U.S. patent application number 12/748405 was filed with the patent office on 2010-09-30 for toe joint replacement models.
This patent application is currently assigned to WRIGHT STATE UNIVERSITY. Invention is credited to Tarun K. Goswami, Alexander O. Sheets, Allison L. Van Horn.
Application Number | 20100249942 12/748405 |
Document ID | / |
Family ID | 42785220 |
Filed Date | 2010-09-30 |
United States Patent
Application |
20100249942 |
Kind Code |
A1 |
Goswami; Tarun K. ; et
al. |
September 30, 2010 |
TOE JOINT REPLACEMENT MODELS
Abstract
In various embodiments, provided are implantable devices for
replacing all or a portion of a metatarsophalangeal joint,
comprising (i) a metatarsal component comprising a substantially
convex bearing surface; or (ii) a phalanx component comprising a
substantially concave bearing surface; or (iii) both. In various
embodiments, also provided are methods of treating hallux valgus by
replacing all or a portion of a metatarsophalangeal joint with one
or more of the provided implantable devices.
Inventors: |
Goswami; Tarun K.;
(Beavercreek, OH) ; Van Horn; Allison L.;
(Centerville, OH) ; Sheets; Alexander O.; (Dayton,
OH) |
Correspondence
Address: |
DINSMORE & SHOHL LLP
FIFTH THIRD CENTER, ONE SOUTH MAIN STREET, SUITE 1300
DAYTON
OH
45402-2023
US
|
Assignee: |
WRIGHT STATE UNIVERSITY
Dayton
OH
|
Family ID: |
42785220 |
Appl. No.: |
12/748405 |
Filed: |
March 27, 2010 |
Related U.S. Patent Documents
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Application
Number |
Filing Date |
Patent Number |
|
|
61163920 |
Mar 27, 2009 |
|
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|
Current U.S.
Class: |
623/21.19 |
Current CPC
Class: |
A61F 2002/30387
20130101; A61F 2002/4233 20130101; A61F 2230/0069 20130101; A61F
2/30749 20130101; A61F 2/4225 20130101; A61F 2002/30579 20130101;
A61F 2230/0067 20130101; A61F 2220/0025 20130101; A61F 2002/30205
20130101; A61F 2002/30495 20130101; A61F 2002/30884 20130101; A61F
2002/30878 20130101; A61F 2002/30405 20130101; A61F 2220/0033
20130101; A61F 2002/305 20130101; A61F 2002/30331 20130101; A61F
2002/3085 20130101; A61F 2/30734 20130101; A61F 2002/30332
20130101; A61F 2002/30224 20130101; A61F 2220/0008 20130101 |
Class at
Publication: |
623/21.19 |
International
Class: |
A61F 2/42 20060101
A61F002/42 |
Claims
1. An implantable device for replacing all or a portion of a
metatarsophalangeal joint, comprising: (i) a metatarsal component
for surgical implantation into the distal end of a metatarsal bone,
comprising: a metatarsal articulation member comprising a
substantially convex bearing surface; a base member adapted to be
fixed within the metatarsal bone; and a locking member adapted to
mechanically join the metatarsal articulation member to the base
member; (ii) a phalanx component for surgical implantation into the
proximal end of a proximal phalanx bone, comprising: a phalanx
articulation member comprising a substantially concave bearing
surface; a base member adapted to be fixed within the phalanx bone;
and a locking member adapted to mechanically join the phalanx
articulation member to the base member; wherein the metatarsal
component and the phalanx component are adapted to cooperatively
engage when implanted such that the metatarsal articulation member
and the phalanx articulation member may move with respect to each
other and collectively serve as a prosthetic metatarsophalangeal
joint.
2. A device according to claim 1, comprising a material of
composition selected from ultra-high molecular weight polyethylene,
stainless steel, titanium, titanium alloy,
chromium-cobalt-molybdenum alloy, pyrocarbon, and combinations
thereof.
3. An implantable device for replacing all or a portion of a
metatarsophalangeal joint, comprising: (i) a metatarsal component
for surgical implantation into the distal end of a metatarsal bone,
comprising: a metatarsal articulation member comprising a
substantially convex bearing surface and a stem adapted to receive
a portion of a locking member; a base member adapted to be fixed
within the metatarsal bone, the base member comprising a cavity
adapted to receive at least a portion of the stem and a portion of
the locking member; and a locking member adapted to be received by
the stem and cavity; wherein when the stem is received in the
cavity and the locking member is received by the stem and cavity,
the metatarsal articulation member is mechanically joined to the
base member; (ii) a phalanx component for surgical implantation
into the proximal end of a proximal phalanx bone, comprising: a
phalanx articulation member comprising a substantially concave
bearing surface and a stem adapted to receive a portion of a
locking member; a base member adapted to be fixed within the
phalanx bone, the base member comprising a cavity adapted to
receive at least a portion of the stem and a portion of the locking
member; and a locking member adapted to be received by the stem and
cavity; wherein when the stem is received in the cavity and the
locking member is received by the stem and cavity, the phalanx
articulation member is mechanically joined to the base member;
wherein the metatarsal component and the phalanx component are
adapted to cooperatively engage when implanted such that the
metatarsal articulation member and the phalanx articulation member
may move with respect to each other and collectively serve as a
prosthetic metatarsophalangeal joint.
4. A device according to claim 3, wherein at least one of the stem
of the metatarsal component and the stem of the phalanx component
comprises a slot adapted to receive at least a portion of a locking
member.
5. A device according to claim 4, wherein at least one of the
cavity of the metatarsal component and the cavity of the phalanx
component comprises a slot adapted to receive at least a portion of
a locking member.
6. A device according to claim 4, wherein the locking member is a
flexible spring member adapted to be received within the slot of an
articulation member and the slot of a base member of a metatarsal
component or a phalanx component.
7. A device according to claim 3, wherein the base member of the
metatarsal component, the base member of the phalanx component, or
both have a shape selected from cylindrical, conical, or
tapered.
8. A device according to claim 7, wherein at least one of the base
members comprises one or more peripherally positioned flanges
adapted to be received within a cavity of a resected bone.
9. A device according to claim 8, wherein the flanges are flexible
spring members that, when inserted into the cavity, exert
sufficient tension to fix the base member within the bone.
10. A device according to claim 9, comprising four equidistant
longitudinally positioned flanges.
11. A device according to claim 3, comprising a material of
composition selected from ultra-high molecular weight polyethylene,
stainless steel, titanium, titanium alloy,
chromium-cobalt-molybdenum alloy, pyrocarbon, and combinations
thereof.
12. An implantable device for replacing all or a portion of a
metatarsophalangeal joint, comprising: (i) a metatarsal component
for surgical implantation into the distal end of a metatarsal bone,
comprising: a metatarsal articulation member comprising a
substantially convex bearing surface and a locking member; a base
member adapted to be fixed within the metatarsal bone, the base
member comprising a cavity adapted to receive the locking member;
wherein when the locking member is received by the cavity, the
metatarsal articulation member is mechanically joined to the base
member; (ii) a phalanx component for surgical implantation into the
proximal end of a proximal phalanx bone, comprising: a phalanx
articulation member comprising a substantially concave bearing
surface and a locking member; a base member adapted to be fixed
within the phalanx bone, the base member comprising a cavity
adapted to receive the locking member; wherein when the locking
member is received by the cavity, the phalanx articulation member
is mechanically joined to the base member; wherein the metatarsal
component and the phalanx component are adapted to cooperatively
engage when implanted such that the metatarsal articulation member
and the phalanx articulation member may move with respect to each
other and collectively serve as a prosthetic metatarsophalangeal
joint.
13. A device according to claim 12, wherein the base member of the
metatarsal component, the base member of the phalanx component, or
both have a shape selected from cylindrical, conical, or
tapered.
14. A device according to claim 13, wherein at least one of the
base members comprises one or more peripherally positioned flanges
adapted to be received within a cavity of a resected bone.
15. A device according to claim 14, wherein the flanges are
flexible spring members that, when inserted into the cavity, exert
sufficient tension to fix the base member within the bone.
16. A device according to claim 15, comprising four equidistant
longitudinally positioned flanges.
17. A device according to claim 12, comprising a material of
composition selected from ultra-high molecular weight polyethylene,
stainless steel, titanium, titanium alloy,
chromium-cobalt-molybdenum alloy, pyrocarbon, and combinations
thereof.
18. An implantable device for replacing all or a portion of a
metatarsophalangeal joint, comprising: (i) a metatarsal component
for surgical implantation into the distal end of a metatarsal bone,
comprising: a metatarsal articulation member comprising a
substantially convex bearing surface and a cavity adapted to
receive at least a portion of a locking member; a base member
adapted to be fixed within the metatarsal bone, comprising a head
portion, a body portion, and a continuous cavity; and a locking
member adapted to be at least partially received by the metatarsal
articulation member cavity; wherein when the locking member is
received within the metatarsal articulation member cavity, the
metatarsal articulation member is mechanically joined to the base
member; (ii) a phalanx component for surgical implantation into the
proximal end of a proximal phalanx bone, comprising: a phalanx
articulation member comprising a substantially convex bearing
surface and a cavity adapted to receive at least a portion of a
locking member; a base member adapted to be fixed within the
phalanx bone, comprising a head portion, a body portion, and a
continuous cavity; and a locking member adapted to be at least
partially received by the phalanx articulation member cavity;
wherein when the locking member is received within the phalanx
articulation member cavity, the phalanx articulation member is
mechanically joined to the base member; wherein the metatarsal
component and the phalanx component are adapted to cooperatively
engage when implanted such that the metatarsal articulation member
and the phalanx articulation member may move with respect to each
other and collectively serve as a prosthetic metatarsophalangeal
joint.
19. A device according to claim 18, wherein the body portion of the
metatarsal component, the body portion of the phalanx component, or
both have a shape selected from cylindrical, conical, or
tapered.
20. A device according to claim 18, wherein the continuous cavity
of the metatarsal component, the continuous cavity of the phalanx
component, or both is adapted to receive a screw member that, when
received within the continuous cavity, causes the body portion to
expand and exert sufficient tension to fix the base member within
the bone.
21. A device according to claim 20, wherein the locking member is
at least a portion of the screw member.
22. A device according to claim 20, wherein the locking member is
at least one pair of flanges opposably positioned on the head
portion.
23. A device according to claim 20, comprising a material of
composition selected from ultra-high molecular weight polyethylene,
stainless steel, titanium, titanium alloy,
chromium-cobalt-molybdenum alloy, pyrocarbon, and combinations
thereof.
24. An implantable device for replacing all or a portion of a
metatarsophalangeal joint, comprising: (i) a metatarsal component
for surgical implantation into the distal end of a metatarsal bone,
comprising: a metatarsal articulation member comprising a
substantially convex bearing surface; and a locking member
comprising a screw thread adapted to fix the metatarsal component
in the metatarsal bone; (ii) a phalanx component for surgical
implantation into the proximal end of a proximal phalanx bone,
comprising: a phalanx articulation member comprising a
substantially concave bearing surface; and a locking member
comprising a screw thread adapted to fix the phalanx component in
the phalanx bone; wherein the metatarsal component and the phalanx
component are adapted to cooperatively engage when implanted such
that the metatarsal articulation member and the phalanx
articulation member may move with respect to each other and
collectively serve as a prosthetic metatarsophalangeal joint.
25. A device according to claim 24, comprising a material of
composition selected from ultra-high molecular weight polyethylene,
stainless steel, titanium, titanium alloy,
chromium-cobalt-molybdenum alloy, pyrocarbon, and combinations
thereof.
26. An implantable device for replacing all or a portion of a
metatarsophalangeal joint, comprising: (i) a metatarsal component
for surgical implantation into the distal end of a metatarsal bone,
comprising: a metatarsal articulation member comprising a
substantially convex parabolic bearing surface terminating at
equidistantly positioned ends; (ii) a phalanx component for
surgical implantation into the proximal end of a proximal phalanx
bone, comprising: a phalanx articulation member comprising a
substantially concave bearing surface; wherein the metatarsal
component and the phalanx component are adapted to cooperatively
engage when implanted such that the metatarsal articulation member
and the phalanx articulation member may move with respect to each
other and collectively serve as a prosthetic metatarsophalangeal
joint.
27. A device according to claim 26, comprising a material of
composition selected from ultra-high molecular weight polyethylene,
stainless steel, titanium, titanium alloy,
chromium-cobalt-molybdenum alloy, pyrocarbon, and combinations
thereof.
28. A method of treating hallux valgus, comprising surgically
replacing a metatarsophalangeal joint with an implantable device
selected from: (I) an implantable two-component device comprising:
(i) a metatarsal component for surgical implantation into the
distal end of a metatarsal bone, comprising: a metatarsal
articulation member comprising a substantially convex bearing
surface; a base member adapted to be fixed within the metatarsal
bone; and a locking member adapted to mechanically join the
metatarsal articulation member to the base member; and (ii) a
phalanx component for surgical implantation into the proximal end
of a proximal phalanx bone, comprising: a phalanx articulation
member comprising a substantially concave bearing surface; a base
member adapted to be fixed within the phalanx bone; and a locking
member adapted to mechanically join the phalanx articulation member
to the base member; wherein the metatarsal component and the
phalanx component are adapted to cooperatively engage when
implanted such that the metatarsal articulation member and the
phalanx articulation member may move with respect to each other and
collectively serve as a prosthetic metatarsophalangeal joint; (II)
an implantable two-component device comprising: (i) a metatarsal
component for surgical implantation into the distal end of a
metatarsal bone, comprising: a metatarsal articulation member
comprising a substantially convex bearing surface; and a locking
member comprising a screw thread adapted to fix the metatarsal
component in the metatarsal bone; (ii) a phalanx component for
surgical implantation into the proximal end of a proximal phalanx
bone, comprising: a phalanx articulation member comprising a
substantially concave bearing surface; and a locking member
comprising a screw thread adapted to fix the phalanx component in
the phalanx bone; wherein the metatarsal component and the phalanx
component are adapted to cooperatively engage when implanted such
that the metatarsal articulation member and the phalanx
articulation member may move with respect to each other and
collectively serve as a prosthetic metatarsophalangeal joint; and
(III) an implantable two-component device comprising: (i) a
metatarsal component for surgical implantation into the distal end
of a metatarsal bone, comprising: a metatarsal articulation member
comprising a substantially convex parabolic bearing surface
terminating at equidistantly positioned ends; (ii) a phalanx
component for surgical implantation into the proximal end of a
proximal phalanx bone, comprising: a phalanx articulation member
comprising a substantially concave bearing surface; wherein the
metatarsal component and the phalanx component are adapted to
cooperatively engage when implanted such that the metatarsal
articulation member and the phalanx articulation member may move
with respect to each other and collectively serve as a prosthetic
metatarsophalangeal joint.
Description
CROSS REFERENCE TO RELATED APPLICATION
[0001] This application claims priority to and any other benefit of
U.S. Provisional Patent Application Ser. No. 61/163,920, filed Mar.
27, 2009, the entirety of which is incorporated by reference
herein.
BACKGROUND
[0002] Hallux valgus is characterized as a deformity of the great
toe (hallux) and first metatarsophalangeal joint, wherein the first
metatarsal is medially deviated, the great toe is laterally
deviated and/or rotated on the head of the metatarsal, the plantar
pad and sesamoids are displaced with the toe, and the ligaments on
the medial side of the metatarsophalangeal joint are stretched. The
position of the great toe with respect to the second toe can be
overriding, underriding, abutting, or without contact. Thus, hallux
valgus can involve transverse plane deformities (hallux abductus),
or frontal and transverse plane deformities (hallux abductovalgus).
With respect to deformities in the transverse plane, the angle
between the longitudinal axis of the metatarsals of the first and
second toes (intermetatarsal angle) typically deviates beyond the
normal range of 8-12.degree.. With respect to deformities in the
frontal plane, the angle between the longitudinal axis of the
metatarsal and proximal phalanx of the great toe (hallux valgus
angle) typically deviates beyond the normal upper limit of
15-20.degree..
[0003] In addition to physical deformity, hallux valgus is often
accompanied by formation of a callous, bursa, or bunion over the
first metatarsal head, pain in the first metatarsophalangeal joint
during ambulation, pain in the metatarsal head, and combinations
thereof.
[0004] Hallux valgus is estimated to affect more than 43 million
people in the United States, with incidence more predominate in
females, those older than 60 years of age, teenagers who wear high
heels, and athletes. It can develop due to numerous factors,
including biomechanical instability (e.g., excessive protonation),
arthritic/metabolic conditions (e.g., osteo/rheumatoid arthritis),
neuromuscular disease (e.g., multiple sclerosis), trauma (e.g.,
soft-tissue sprains, dislocations, and sports-related injuries),
and structural deformities (e.g., abnormal metatarsal length).
Additionally, there tends to be familial disposition to developing
hallux valgus.
[0005] Development of hallux valgus typically occurs in four
stages. See Root, M L, "Normal and Abnormal Function of the Foot,"
Vol. 2, Clinical Biomechanics (1977). The first stage is associated
with lateral subluxation (partial or complete dislocation) of the
proximal phalanx. The second stage is associated with increased
abduction of the hallux in the transverse and/or frontal planes.
The third stage is associated with additional subluxation at the
first metatarsophalangeal joint. The fourth stage is associated
with dislocation of the first metatarsophalangeal joint.
[0006] Hallux valgus is a complex deformity and various approaches
to treating or correcting the deformity may be available. For
example, when hallux valgus is in its early stages, or where
surgical correction is contraindicated, braces, straps, splints,
orthotics, or combinations thereof may be used to manage
progression of the deformity and relieve the associated symptoms.
However, surgery is the only means of correcting the deformity.
[0007] The first surgical treatment to address hallux valgus dates
to 1881 when an osteotomy procedure involving an incision medial to
the extensor hallucis longus, followed by incision of the
periosteum, removal of exostosis, removal of bone from behind the
caputulum of the metatarsus, and suturing of the bone. Since this
forerunning procedure, numerous other procedures have been
developed, all with the goal of addressing the deformity with
minimal complications. Such surgical procedures, while varying
depending upon the nature of the deformity and particular needs of
the patient, generally allow for establishment of a congruous first
metatarsophalangeal joint, reduction of the intermetatarsal angle,
realignment of the sesamoids, realignment of the hallux to a rectus
(rather than an abductus) position, and maintenance or increase of
the range of motion of the first metatarsophalangeal joint.
[0008] Typical surgical procedures involve one or more of osteotomy
of the metatarsal head, osteotomy of the metatarsal shaft or base,
fusion of the metatarsophalangeal joint, resectional arthroplasty,
resectional arthroplasty with a partial (hemi) implant, and
resectional arthroplasty with a total implant. With respect to
procedures involving an implant, numerous devices for use therewith
are known in the art. For example, known hemi arthroplasty devices,
which are typically used when the proximal phalanx is degenerated
but the metatarsal head is intact, include the BioPro.RTM. hemi toe
implant (BioPro, Inc., Port Huron, Mich.); Futura.TM. Metal Hemi
Toe implant (Tornier, Edina, Minn.); K2.TM. Hemi Toe Implant System
(Integra LifeSciences Corp., Plainsboro, N.J.); and Swanson.TM.
Great Toe Implant (Wright Medical Technology, Inc., Arlington,
Tenn.), all of which are depicted in FIG. 1A. Examples of known
double-stemmed hinges, which are typically used when both the
proximal phalanx and the metatarsal head are degenerated, include
the Swanson.TM. Flexible Hinge Toe implant (Wright Medical
Technology, Inc., Arlington, Tenn.); GAIT Implant.TM. (Sgarlato
Med, San Jose, Calif.); and Futura.TM. Flexible Great Toe implant
(Tornier, Edina, Minn.), all of which are depicted in FIG. 1B. In
addition, examples of known two-component devices, which are also
typically used when both the proximal phalanx and the metatarsal
head are degenerated, include the Total Toe.TM. System (Biomet,
Warsaw, Ind.); Bio-Action.TM. Great Toe Implant (Osteomed, Inc.,
Addison, Tex.); ReFlexion.TM. 1.sup.st MPJ Implant System
(Osteomed, Inc., Addison, Tex.); and KGTI.TM. Kinetik Great Toe
Implant System (Integra LifeSciences Corp., Plainsboro, N.J.), all
of which are depicted in FIG. 1C.
[0009] Along with the knowledge in the art of numerous implant
devices is the knowledge of numerous problems associated with such
devices. Examples include, but are not limited to, shearing stress,
loosening of the device, fragmentation, fracture through the
proximal phalanx, breakage of hinged implants at the hinge,
misalignment, recurrence of deformity, limited joint motion,
development of plantar keratosis, development of tenderness around
the joint, development of long flexor tendonitis, development of
metatarsalgia, and development of metallosis. Accordingly, there is
need in the art for improved implant devices for use in correcting
hallux valgus. Moreover, there is need in the art for devices that
are aligned and articulate in a manner consistent with natural
motion of the metatarsophalangeal joint, that resist torsion forces
applied to the device, and that are designed to be implanted
without complex assembly, positioning, or other manipulation by the
surgeon.
SUMMARY
[0010] Embodiments of the present invention provide novel
implantable devices used to replace all or a portion of a joint of
the human toe. In some embodiments, the implantable devices are
designed to replace all or a portion of the metatarsophalangeal
joint. In some embodiments, the devices replace all or a portion of
the metatarsal head and function as the metatarsal component of the
metatarsophalangeal joint. In some embodiments, the devices replace
all or a portion of the proximal end of the proximal phalanx and
function as the phalanx component of the metatarsophalangeal
joint.
[0011] In various embodiments, the implantable devices replace all
or a portion of a metatarsophalangeal joint and comprise (i) a
metatarsal component for surgical implantation into the distal end
of a metatarsal bone, comprising a metatarsal articulation member
comprising a substantially convex bearing surface; or (ii) a
phalanx component for surgical implantation into the proximal end
of a proximal phalanx bone, comprising a phalanx articulation
member comprising a substantially concave bearing surface; or (iii)
a metatarsal component for surgical implantation into the distal
end of a metatarsal bone, comprising a metatarsal articulation
member comprising a substantially convex bearing surface; and a
phalanx component for surgical implantation into the proximal end
of a proximal phalanx bone, comprising a phalanx articulation
member comprising a substantially concave bearing surface. In some
embodiments, the metatarsal component and the phalanx component are
adapted to cooperatively engage when implanted such that the
metatarsal articulation member and the phalanx articulation member
may move with respect to each other and collectively serve as a
prosthetic metatarsophalangeal joint.
[0012] In various embodiments, also provided are methods of
treating hallux valgus, comprising replacing all or a portion of a
metatarsophalangeal joint with implantable devices selected from:
(i) a metatarsal component for surgical implantation into the
distal end of a metatarsal bone, comprising a metatarsal
articulation member comprising a substantially convex bearing
surface; (ii) a phalanx component for surgical implantation into
the proximal end of a proximal phalanx bone, comprising a phalanx
articulation member comprising a substantially concave bearing
surface; or (iii) a metatarsal component for surgical implantation
into the distal end of a metatarsal bone, comprising a metatarsal
articulation member comprising a substantially convex bearing
surface; and a phalanx component for surgical implantation into the
proximal end of a proximal phalanx bone, comprising a phalanx
articulation member comprising a substantially concave bearing
surface.
[0013] These and additional features of the invention will become
apparent in the course of the following detailed description.
BRIEF DESCRIPTION OF THE DRAWINGS
[0014] A more complete appreciation of the invention and the many
embodiments thereof will be readily obtained as the same becomes
better understood by reference to the following detailed
description when considered in connection with the accompanying
drawings, wherein:
[0015] FIG. 1 illustrates various examples of implantable devices
known in the art;
[0016] FIGS. 2-4 illustrate one example of an implantable
two-component device and elements thereof;
[0017] FIGS. 5-7 illustrate an additional example of an implantable
two-component device and elements thereof;
[0018] FIGS. 8-10 illustrate a further example of an implantable
two-component device and elements thereof;
[0019] FIGS. 11-13 also illustrate one example of an implantable
two-component device and elements thereof;
[0020] FIGS. 14-16 illustrate an additional example of an
implantable two-component device and elements thereof;
[0021] FIGS. 17-19 illustrate a further example of an implantable
two-component device and elements thereof;
[0022] FIGS. 20-22 also illustrate an example of an implantable
two-component device and elements thereof;
[0023] FIGS. 23-25 illustrate an additional example of an
implantable two-component device and elements thereof;
[0024] FIGS. 26-27 illustrate a further example of an implantable
two-component device and elements thereof;
[0025] FIGS. 28-30 also illustrate one example of an implantable
two-component device and elements thereof;
[0026] FIG. 31 illustrates the bones of the foot, including those
most relevant to hallux valgus: A, distal phalanx; B,
interphalangeal joint; C, proximal phalanx; D, metatarsophalangeal
joint; E, metatarsal; and
[0027] FIG. 32 illustrates deformity of the A, hallux valgus angle;
and B, intermetatarsal angle. In various embodiments, the provided
implants are designed to correct one or both angles in a subject
foot.
DETAILED DESCRIPTION
[0028] The present invention will now be described with occasional
reference to the specific embodiments of the invention. This
invention may, however, be embodied in different forms and should
not be construed as limited to the embodiments set forth herein.
Rather, these embodiments are provided so that this disclosure will
be thorough and complete, and will fully convey the scope of the
invention to those skilled in the art. Similarly, the present
invention should not be considered limited to the specific examples
described herein, but rather should be understood to cover all
aspects of the invention. Various modifications and equivalents, as
well as numerous structures and devices to which the present
invention may be applicable will be readily apparent to those of
skill in the art. Those skilled in the art will understand that
various changes may be made without departing from the scope of the
invention, which is not to be considered limited to what is
described in the specification.
[0029] Unless otherwise defined, all technical and scientific terms
used herein have the same meaning as commonly understood by one of
ordinary skill in the art to which this invention belongs. The
terminology used in the description of the invention herein is for
describing particular embodiments only and is not intended to be
limiting. As used in the description of the invention and the
appended claims, the singular forms "a," "an," and "the" are
intended to include the plural forms as well, unless the context
clearly indicates otherwise.
[0030] Unless otherwise indicated, all numbers expressing
quantities of ingredients, properties such as molecular weight,
reaction conditions, and so forth as used in the specification and
claims are to be understood as being modified in all instances by
the term "about." Additionally, the disclosure of any ranges in the
specification and claims are to be understood as including the
range itself and also anything subsumed therein, as well as
endpoints. Unless otherwise indicated, the numerical properties set
forth in the specification and claims are approximations that may
vary depending on the desired properties sought to be obtained in
embodiments of the present invention. Notwithstanding that
numerical ranges and parameters setting forth the broad scope of
the invention are approximations, the numerical values set forth in
the specific examples are reported as precisely as possible. Any
numerical values, however, inherently contain certain errors
necessarily resulting from error found in their respective
measurements.
[0031] Provided are implantable devices used to replace all or part
of a human toe joint. In some embodiments, the devices replace all
or a portion of the metatarsophalangeal joint, said devices being
designed to be positioned during implantation such that when the
muscles and tendons of the foot exert a force on the natural
phalanx and metatarsal bones, the components of the device provide
functional cooperation that emulates the desired and permissible
movements of the metatarsophalangeal joint. In some embodiments,
the provided devices align and articulate in a manner consistent
with natural motion of the joint. In some embodiments, the devices
are adapted to be implanted without complex assembly, positioning,
or other manipulation by the surgeon.
[0032] In various embodiments, the implantable devices replace all
or a portion of a metatarsophalangeal joint and comprise (i) a
metatarsal component for surgical implantation into the distal end
of a metatarsal bone, comprising a metatarsal articulation member
comprising a substantially convex bearing surface; or (ii) a
phalanx component for surgical implantation into the proximal end
of a proximal phalanx bone, comprising a phalanx articulation
member comprising a substantially concave bearing surface; or (iii)
a metatarsal component for surgical implantation into the distal
end of a metatarsal bone, comprising a metatarsal articulation
member comprising a substantially convex bearing surface; and a
phalanx component for surgical implantation into the proximal end
of a proximal phalanx bone, comprising a phalanx articulation
member comprising a substantially concave bearing surface.
Accordingly, these devices can be used for total joint replacement
when a metatarsal and a phalanx component are implanted, or for
partial (hemi) replacement when only one of the metatarsal and
phalanx component is implanted.
[0033] In various embodiments, the implantable devices replace all
or a portion of a metatarsophalangeal joint and comprise: (i) a
metatarsal component for surgical implantation into the distal end
of a metatarsal bone, comprising a metatarsal articulation member
comprising a substantially convex bearing surface; a base member
adapted to be fixed within the metatarsal bone; and a locking
member adapted to mechanically join the metatarsal articulation
member to the base member; and (ii) a phalanx component for
surgical implantation into the proximal end of a proximal phalanx
bone, comprising a phalanx articulation member comprising a
substantially concave bearing surface; a base member adapted to be
fixed within the phalanx bone; and a locking member adapted to
mechanically join the phalanx articulation member to the base
member; wherein the metatarsal component and the phalanx component
are adapted to cooperatively engage when implanted such that the
metatarsal articulation member and the phalanx articulation member
may move with respect to each other and collectively serve as a
prosthetic metatarsophalangeal joint.
[0034] In various embodiments, the implantable devices replace all
or a portion of a metatarsophalangeal joint and comprise: (i) a
metatarsal component for surgical implantation into the distal end
of a metatarsal bone, comprising a metatarsal articulation member
comprising a substantially convex bearing surface; and a locking
member comprising a screw thread adapted to fix the metatarsal
component in the metatarsal bone; and (ii) a phalanx component for
surgical implantation into the proximal end of a proximal phalanx
bone, comprising a phalanx articulation member comprising a
substantially concave bearing surface; and a locking member
comprising a screw thread adapted to fix the phalanx component in
the phalanx bone; wherein the metatarsal component and the phalanx
component are adapted to cooperatively engage when implanted such
that the metatarsal articulation member and the phalanx
articulation member may move with respect to each other and
collectively serve as a prosthetic metatarsophalangeal joint.
[0035] In various embodiments, the implantable devices replace all
or a portion of a metatarsophalangeal joint and comprise: (i) a
metatarsal component for surgical implantation into the distal end
of a metatarsal bone, comprising a metatarsal articulation member
comprising a substantially convex parabolic bearing surface
terminating at equidistantly positioned ends; and (ii) a phalanx
component for surgical implantation into the proximal end of a
proximal phalanx bone, comprising a phalanx articulation member
comprising a substantially concave bearing surface; wherein the
metatarsal component and the phalanx component are adapted to
cooperatively engage when implanted such that the metatarsal
articulation member and the phalanx articulation member may move
with respect to each other and collectively serve as a prosthetic
metatarsophalangeal joint.
[0036] The provided devices may be comprised of any material
suitable for implant devices. For example, materials that comply
with ASTM F75-01, F90-01, F136-02a, and other applicable
specifications. In some embodiments suitable materials of
composition may be selected from ultra-high molecular weight
polyethylene ("UHMWPE"), stainless steel (including but not limited
to SS 316L), titanium, titanium alloys (including but not limited
to Ti-6Al-4V), chromium-cobalt-molybdenum alloys, pyrocarbon, and
combinations thereof. Properties of some suitable materials are
shown in Table 1. In some embodiments, a device may comprise a
coating for enhancing bone growth. For example, a suitable coating
may be titanium plasma spray. In some embodiments, a device may be
partially or completely formed from pyrocarbon. In some
embodiments, the pyrocarbon is coated with titanium plasma spray.
In some embodiments, UHMWPE is the material of composition used for
the metatarsal bearing surface, the phalanx bearing surface, or
both.
TABLE-US-00001 TABLE 1 Elastic Tensile Modulus Yield Material
Modulus Strength Density of Shear Strength UHMWPE 1258 MPa 45.8 MPa
932 kg/m3 11-13 Mpa 23.56 MPa Stainless 200 GPa 485 MPa 8027 kg/m3
82 GPa 170 MPa Steel 316L Ti-6Al-4V 113.8 GPa 950 MPa 4430 Kg/m3 44
GPa 880 MPa Pyrocarbon 25 GPa 420 MPa 1700 kg/m3 -- 345 MPa
[0037] Referring to FIGS. 2-10, illustrated are various examples of
implantable devices of the invention which are designed to replace
all or a portion of a metatarsophalangeal joint. Such devices
comprise one or more of: (i) a metatarsal component for surgical
implantation into the distal end of a metatarsal bone, comprising a
metatarsal articulation member comprising a substantially convex
bearing surface and a stem adapted to receive a portion of a
locking member; a base member adapted to be fixed within the
metatarsal bone, the base member comprising a cavity adapted to
receive at least a portion of the stem and a portion of the locking
member; and a locking member adapted to be received by the stem and
cavity; wherein when the stem is received in the cavity and the
locking member is received by the stem and cavity, the metatarsal
articulation member is mechanically joined to the base member; and
(ii) a phalanx component for surgical implantation into the
proximal end of a proximal phalanx bone, comprising a phalanx
articulation member comprising a substantially concave bearing
surface and a stem adapted to receive a portion of a locking
member; a base member adapted to be fixed within the phalanx bone,
the base member comprising a cavity adapted to receive at least a
portion of the stem and a portion of the locking member; and a
locking member adapted to be received by the stem and cavity;
wherein when the stem is received in the cavity and the locking
member is received by the stem and cavity, the phalanx articulation
member is mechanically joined to the base member.
[0038] In those embodiment wherein one of the components is
implanted, the chosen component is adapted to cooperatively engage
with and move with respect to either the proximal end of the
proximal phalanx bone or the distal end of the metatarsal bone. In
those embodiments wherein both of the components are implanted, the
metatarsal component and the phalanx component are adapted to
cooperatively engage such that the metatarsal articulation member
and the phalanx articulation member move with respect to each other
and collectively serve as a prosthetic metatarsophalangeal
joint.
[0039] Referring to FIG. 2, one example of a two-component implant
device 1 comprises a metatarsal component 2 and a phalanx component
3. The metatarsal component 2 is designed to be implanted into the
distal end of a resected metatarsal bone to replace all or a
portion of the metatarsal head and function as the metatarsal
component of the metatarsophalangeal joint. The metatarsal
component 2 comprises a base member 4, a metatarsal articulation
member 5, and a locking member 6. The base member 4 may be of any
suitable length and dimension to allow for fixation within the
metatarsal bone, and may be fixed by any medically suitable means.
In some embodiments, the base member 4 is designed to be implanted
in approximately one third of the length of the metatarsal bone. In
some embodiments, it may be fixed with bone cement.
[0040] The phalanx component 3 is designed to be implanted into the
proximal end of a resected proximal phalanx bone to replace all or
a portion of the proximal end of the proximal phalanx and function
as the phalanx component of the metatarsophalangeal joint. The
phalanx component 3 comprises a base member 7, a phalanx
articulation member 8, and a locking member 9. The base member 7
may be of any suitable length and dimension to allow for fixation
within the phalanx bone, and may be fixed by any medically suitable
means. In some embodiments, the phalanx component 3 is designed to
be implanted in approximately half of the length of the phalanx
bone. In some embodiments, it may be fixed with bone cement.
[0041] In some embodiments, one or both of the metatarsal component
2 and the phalanx component 3 are implanted into the human foot to
replace all or a portion of the metatarsophalangeal joint. In some
embodiments, one or both components 2, 3 may be implanted in a
primary resectional arthroplasty procedure, in a revision
arthroplasty procedure performed to replace or compensate for a
failed implant, or combinations thereof. In some embodiments, one
or both components 2, 3 are implanted in a primary resectional
arthroplasty procedure. In some embodiments, each component 2, 3
implanted may be selected from small, medium, or large sizes as
necessary to approximate the anatomy of the subject. In some
embodiments, the components 2, 3 may comprise one or more
dimensions as set forth in Table 2. In some embodiments, each
component 2, 3 and elements thereof may be customized to the
anatomy of the subject.
TABLE-US-00002 TABLE 2 Dimension (mm) Metatarsal Base Member Length
22-26 Base Member Outer Diameter Top 7-10 Base Member Outer
Diameter Bottom 7-10 Articulation Member Length 12-16 (Excluding
Head Portion) Articulation Member Outer Diameter Top 4-7
Articulation Member Outer Diameter Bottom 3-6 Head Portion Diameter
10-13 Locking Member Outer Diameter 4-7 Locking Member Inner
Diameter 2-5 Locking Member Thickness 0.5 Head Portion Height 2
Phalanx Base Member Length 18-22 Base Member Outer Diameter Top
10-13 Base Member Outer Diameter Bottom 10-13 Articulation Member
Length 10-15 (Excluding Head Portion) Articulation Member Outer
Diameter Top 7-10 Articulation Member Outer Diameter Bottom 6-8
Head Portion Diameter 10-13 Locking Member Outer Diameter 7-10
Locking Member Inner Diameter 5-8 Locking Member Thickness 0.5 Head
Portion Depth 2
[0042] A further illustrated in FIG. 3, the base member 4 of the
metatarsal component 2 is cylindrical and has a generally circular
cross-section. However, it is also contemplated that a base member
4 may alternatively be non-cylindrical, have another suitable
cross-section, or combinations thereof, provided that other
elements of the metatarsal component 2 are also adapted to fit such
alternatives. For example, a base member 4 may have a cross-section
selected from generally elliptical, square, triangular, or other
suitable shape. The base member 4 comprises a continuous first end
11, a non-continuous second end 12, and a cavity 10 for receiving a
portion of the metatarsal articulation member 5. The cavity 10
comprises a first end 13 recessed within the base member 4, a
second end 14 that is partially shared with the second end 12 of
the base member 4, and a peripheral slot 15 for receiving a portion
of the locking member 6. As shown, the cavity 10 is generally
conical or tapered and has a generally circular cross-section.
However, it is also contemplated that the cavity 10 may
alternatively be non-conical or non-tapered, have another suitable
cross-section, or combinations thereof, provided that other
elements of the metatarsal component 2 are also adapted to fit such
alternatives. For example, a cavity 10 may have a cross-section
selected from generally elliptical, square, triangular, or other
suitable shape. The slot 15 is integrated with and formed around
all or a portion of the cavity 10 in a direction away from a
longitudinal axis 16 of the base member 4. As shown, the slot 15
may be positioned at or proximate to the first end 13 of the cavity
10, but it is also contemplated that it may alternatively be
positioned elsewhere along the cavity 10, provided that the
metatarsal articulation member 5 is correspondingly adapted.
Moreover, it is also contemplated that the first end 11 of the base
member 4 may alternatively be non-continuous and partially shared
with the first end 13 of the cavity 10.
[0043] The articulation member 5 of the metatarsal component 2
comprises a head portion 17, a stem 20, and an integral slot 22.
The head portion 17 comprises a substantially convex bearing
surface 18 and a proximal surface 19 opposite thereto. As shown,
the proximal surface 19 is generally planar, but it is also
contemplated that it could be non-planar. The bearing surface 18 is
adapted to emulate the general shape and function of the head
portion of the metatarsal bone within a metatarsophalangeal joint.
The stem 20 protrudes from the center (not labeled) of the proximal
surface 19, terminates at a proximal end 21, and is adapted to be
received within the cavity 10 of the base member 4. When so
received, the proximal surface 19 abuts the second end 12 of the
base member 4. It is also contemplated that the proximal surface 19
could be spaced from the second end 12 when so received. As shown,
the stem 20 is generally conical or tapered and has a generally
circular cross-section. However, it is also contemplated that the
stem 20 may alternatively be non-conical or non-tapered, have
another suitable cross-section, or combinations thereof, provided
that other elements of the metatarsal component 2 are also adapted
to fit such alternatives. For example, a stem 20 may have a
cross-section selected from generally elliptical, square,
triangular, or other suitable shape. The slot 22 is integrated with
and formed in a direction towards a longitudinal axis 23 of the
metatarsal articulation member 5 around all or a portion of the
stem 20, and it is adapted to receive a portion of the locking
member 6. As shown, the slot 22 may be positioned at or proximate
to the proximal end 21, but it is also contemplated that it may
alternatively be positioned elsewhere along the stem 20, provided
that the base member 4 is correspondingly adapted. The stem 20 and
slot 22 are adapted to fit within the cavity 10 of the base member
4 such that both slots 15, 22 are aligned to each receive a portion
and together receive the whole of the locking member 6.
[0044] The locking member 6 is a resilient spring member having at
least a first and a second configuration (not shown) and is adapted
to be received within both slots 15, 22 to mechanically join the
metatarsal articulation member 5 with the base member 4. In some
embodiments, the metatarsal articulation member 5 and the base
member 4 are permanently joined, and as such are effectively a
single component of the implantable device. As shown, the locking
member 6 is non-continuous and has a generally circular
cross-section. However, it is also contemplated that the locking
member 6 may alternatively be continuous, have a different
cross-section, or combinations thereof, provided that other
elements (including, but not limited to the slots 15, 22) of the
metatarsal component 2 are correspondingly adapted. For example, a
locking member 6 could have a cross-section selected from generally
elliptical, square, triangular, or other suitable cross-section. In
some embodiments, the locking member 6 may comprise a resilient
material suitable for surgical implants.
[0045] In some embodiments of assembly, the locking member 6 is
flexed from a first to a second configuration upon insertion
through the partially shared second ends 12, 14 of the base member
4 and cavity 10; remains in the second configuration as it is
advanced along the cavity 10 towards the first end 13; and upon
encountering the slot 15 flexes from the second to the first
configuration as it is received within the slot 15. Alternatively,
it is contemplated that the locking member 6 may flex from the
second to an intermediate third configuration as it is received
within the slot 15.
[0046] In some embodiments of assembly, a portion of the locking
member 6 is received within the slot 22 of the metatarsal
articulating member 5; the stem 20 of said articulating member 5 is
inserted through the shared ends 12, 14 of the base member 4 and
cavity 10 as the locking member 6 flexes from a first to a second
configuration; the locking member 6 remains in the second
configuration as it and the stem 20 are advanced along the cavity
10 towards the first end 13; and upon encountering the slot 15 of
the base member 4, the locking member 6 flexes from the second to
the first configuration as it is received within the slot 15.
Alternatively, it is contemplated that the locking member 6 may
flex from the second to an intermediate third configuration as it
is received within the slot 15.
[0047] As further illustrated in FIG. 4, the base member 7 of the
phalanx component 3 is cylindrical and has a generally circular
cross-section. However, it is also contemplated that a base member
7 may alternatively be non-cylindrical, have another suitable
cross-section, or combinations thereof, provided that other
elements of the phalanx component 3 are also adapted to fit such
alternatives. For example, a base member 7 may have a cross-section
selected from generally elliptical, square, triangular, or other
suitable shape. The base member 7 comprises a continuous first end
24, a non-continuous second end 25, and a cavity 26 for receiving a
portion of the phalanx articulation member 8. The cavity 26
comprises a first end 27 recessed within the base member 7, a
second end 28 that is partially shared with the second end 25 of
the base member 7, and a peripheral slot 29 for receiving a portion
of the locking member 9. As shown, the cavity 26 is generally
conical or tapered and has a generally circular cross-section.
However, it is also contemplated that the cavity 26 may
alternatively be non-conical or non-tapered, have another suitable
cross-section, or combinations thereof, provided that other
elements of the phalanx component 3 are also adapted to fit such
alternatives. For example, a cavity 26 may have a cross-section
selected from generally elliptical, square, triangular, or other
suitable shape. The slot 29 is integrated with and formed around
all or a portion of the cavity 26 in a direction away from a
longitudinal axis 30 of the base member 7. As shown, the slot 29
may be positioned at or proximate to the first end 27, but it is
also contemplated that it may alternatively be positioned elsewhere
along the cavity 26, provided that the phalanx articulation member
8 is correspondingly adapted. Moreover, it is also contemplated
that the first end 24 of the base member 7 may alternatively be
non-continuous and partially shared with the first end 27 of the
cavity 26.
[0048] The articulation member 8 of the phalanx component 3
comprises a head portion 31, a stem 34, and an integral slot 36.
The head portion 31 comprises a substantially concave bearing
surface 32 and a distal surface 33 opposite thereto. As shown, the
distal surface 33 is generally planar, but it is also contemplated
that it could be non-planar. The bearing surface 32 is adapted to
emulate the general shape and function of the proximal portion of
the proximal phalanx bone within a metatarsophalangeal joint. The
stem 34 protrudes from the center (not labeled) of the distal
surface 33, terminates at a distal end 35, and is adapted to be
received within the cavity 26 of the base member 7. When so
received, the distal surface 33 abuts the second end 25 of the base
member 7. It is also contemplated that the distal surface 33 could
be spaced from the second end 25 when so received. As shown, the
stem 34 is generally conical or tapered and has a generally
circular cross-section. However, it is also contemplated that the
stem 34 may alternatively be non-conical or non-tapered, have
another suitable cross-section, or combinations thereof, provided
that other elements of the phalanx component 3 are also adapted to
fit such alternatives. For example, a stem 34 may have a
cross-section selected from generally elliptical, square,
triangular, or other suitable shape. The slot 36 is integrated with
and formed around all or a portion of the stem 34 in a direction
towards a longitudinal axis 37 of the phalanx articulation member
8, and it is adapted to receive a portion of the locking member 9.
As shown, the slot 36 may be positioned at or proximate to the
distal end 35, but it is also contemplated that it may
alternatively be positioned elsewhere along the stem 34, provided
that the base member 7 is correspondingly adapted. The stem 34 and
slot 36 are adapted to fit within the cavity 26 of the base member
7 such that both slots 29, 36 are aligned to each receive a portion
and together receive the whole of the locking member 9.
[0049] The locking member 9 is a resilient spring member having at
least a first and a second configuration (not shown) and is adapted
to be received within both slots 29, 36 to mechanically join the
phalanx articulation member 8 with the base member 7. In some
embodiments, the phalanx articulation member 8 and the base member
7 are permanently joined, and as such are effectively a single
component of the implantable device. As shown, the locking member 9
is non-continuous and has a generally circular cross-section.
However, it is also contemplated that the locking member 9 may
alternatively be continuous, have a different cross-section, or
combinations thereof, provided that other elements (including, but
not limited to the slots 29, 36) of the phalanx component 3 are
correspondingly adapted. For example, a locking member 9 could have
a cross-section selected from generally elliptical, square,
triangular, or other suitable cross-section. In some embodiments,
the locking member 9 may comprise a resilient material suitable for
surgical implants.
[0050] In some embodiments of assembly, the locking member 9 is
flexed from a first to a second configuration upon insertion
through the partially shared second ends 25, 28 of the base member
7 and cavity 26; remains in the second configuration as it is
advanced along the cavity 26 towards the first end 27; and upon
encountering the slot 29 flexes from the second to the first
configuration as it is received within the slot 29. Alternatively,
it is contemplated that the locking member 9 may flex from the
second to an intermediate third configuration as it is received
within the slot 29.
[0051] In some embodiments of assembly, a portion of the locking
member 9 is received within the slot 36 of the phalanx articulating
member 8, the stem 34 of said articulating member 8 is inserted
through the shared ends 25, 28 of the base member 7 and cavity 26
as the locking member 9 flexes from a first to a second
configuration; the locking member 9 remains in the second
configuration as it and the stem 34 are advanced along the cavity
26 towards the first end 27; and upon encountering the slot 29 of
the base member 7, the locking member 9 flexes from the second to
the first configuration as it is received within the slot 29.
Alternatively, it is contemplated that the locking member 9 may
flex from the second to an intermediate third configuration as it
is received within the slot 29.
[0052] Referring to FIGS. 5-7, illustrated is another example of a
two-component implant 38 that comprises a metatarsal component 39
and a phalanx component 40. The metatarsal component 39 is designed
to be implanted into the distal end of a resected metatarsal bone
to replace all or a portion of the metatarsal head and function as
the metatarsal component of the metatarsophalangeal joint. The
metatarsal component 39 comprises a base member 41, a metatarsal
articulation member 42, and a locking member 43. The base member 41
may be of any suitable length and dimension to allow for fixation
within the metatarsal bone, and may be fixed by any medically
suitable means. In some embodiments, the base member 41 is designed
to be implanted in approximately one third of the length of the
metatarsal bone. In some embodiments, it may be fixed with bone
cement.
[0053] The phalanx component 40 is designed to be implanted into
the proximal end of a resected proximal phalanx bone to replace all
or a portion of the proximal end of the proximal phalanx and
function as the phalanx component of the metatarsophalangeal joint.
The phalanx component 40 comprises a base member 44, a phalanx
articulation member 45, and a locking member 46. The base member 44
may be of any suitable length and dimension to allow for fixation
within the phalanx bone, and may be fixed by any medically suitable
means. In some embodiments, the base member 44 is designed to be
implanted in approximately half of the length of the phalanx bone.
In some embodiments, it may be fixed with bone cement.
[0054] In some embodiments, one or both of the metatarsal component
39 and the phalanx component 40 are implanted into the human foot
to replace all or a portion of the metatarsophalangeal joint. In
some embodiments, one or both components 39, 40 may be implanted in
a primary resectional arthroplasty procedure, in a revision
arthroplasty procedure performed to replace or compensate for a
failed implant, or combinations thereof. In some embodiments, one
or both components 39, 40 are implanted in a revision arthroplasty
procedure. In some embodiments, each component 39, 40 implanted may
be selected from small, medium, or large sizes as necessary to
approximate the anatomy of the subject. In some embodiments, the
components 39, 40 may comprise one or more dimensions set forth in
Table 3. In some embodiments, each component 39, 40 and elements
thereof may be customized to the anatomy of the subject.
TABLE-US-00003 TABLE 3 Dimension (mm) Metatarsal Base Member Length
22-26 Base Member Outer Diameter Top 7-10 Base Member Outer
Diameter Bottom 5-7 Articulation Member Length 12-16 (Excluding
Head Portion) Articulation Member Outer Diameter Top 4-7
Articulation Member Outer Diameter Bottom 3-5 Head Portion Diameter
10-13 Locking Member Outer Diameter 4-7 Locking Member Inner
Diameter 2-5 Locking Member Thickness 0.5 Head Portion Height 2
Phalanx Base Member Length 18-22 Base Member Outer Diameter Top
10-13 Base Member Outer Diameter Bottom 7-10 Articulation Member
Length 10-15 (Excluding Head Portion) Articulation Member Outer
Diameter Top 7-10 Articulation Member Outer Diameter Bottom 5-8
Head Portion Diameter 10-13 Locking Member Outer Diameter 7-10
Locking Member Inner Diameter 5-8 Locking Member Thickness 0.5 Head
Portion Depth 2
[0055] As further illustrated in FIG. 6, the base member 41 of the
metatarsal component 39 is conical or tapered and has a generally
circular cross-section. However, it is also contemplated that a
base member 41 may alternatively be non-conical or non-tapered,
have another suitable cross-section, or combinations thereof,
provided that other elements of the metatarsal component 39 are
also adapted to fit such alternatives. For example, a base member
41 may have a cross-section selected from generally elliptical,
square, triangular, or other suitable shape. The base member 41
comprises a continuous first end 44, a non-continuous second end
45, and a cavity 46 for receiving a portion of the metatarsal
articulation member 42. The cavity 46 comprises a first end 47
recessed within the base member 41, a second end 48 that is
partially shared with the second end 45 of the base member 41, and
a peripheral slot 49 for receiving a portion of the locking member
43. As shown, the cavity 46 is generally conical or tapered and has
a generally circular cross-section. However, it is also
contemplated that the cavity 46 may alternatively be non-conical or
non-tapered, have another suitable cross-section, or combinations
thereof, provided that other elements of the metatarsal component
39 are also adapted to fit such alternatives. For example, a cavity
46 may have a cross-section selected from generally elliptical,
square, triangular, or other suitable shape. The slot 49 is
integrated with and formed around all or a portion of the cavity 46
in a direction away from a longitudinal axis 50 of the base member
41. As shown, the slot 49 may be positioned at or proximate to the
first end 47, but it is also contemplated that it may alternatively
be positioned elsewhere along the cavity 46, provided that the
metatarsal articulation member 42 is correspondingly adapted.
Moreover, it is also contemplated that the first end 44 of the base
member 41 may alternatively be non-continuous and partially shared
with the first end 47 of the cavity 46.
[0056] The articulation member 42 of the metatarsal component 39
comprises a head portion 51, a stem 54, and an integral slot 56.
The head portion 51 comprises a substantially convex bearing
surface 52 and a proximal surface 53 opposite thereto. As shown,
the proximal surface 53 is generally planar, but it is also
contemplated that it could be non-planar. The bearing surface 52 is
adapted to emulate the general shape and function of the head
portion of the metatarsal bone within a metatarsophalangeal joint.
The stem 54 protrudes from the center (not labeled) of the proximal
surface 53, terminates at a proximal end 55, and is adapted to be
received within the cavity 46 of the base member 41. When so
received, the proximal surface 53 abuts the second end 45 of the
base member 41. It is also contemplated that the proximal surface
53 could be spaced from the second end 45 when so received. As
shown, the stem 54 is generally conical or tapered and has a
generally circular cross-section. However, it is also contemplated
that the stem 54 may alternatively be non-conical or non-tapered,
have another suitable cross-section, or combinations thereof,
provided that other elements of the metatarsal component 39 are
also adapted to fit such alternatives. For example, a stem 54 may
have a cross-section selected from generally elliptical, square,
triangular, or other suitable shape. The slot 56 is integrated with
and formed around all or a portion of the stem 54 in a direction
towards a longitudinal axis 57 of the metatarsal articulation
member 42, and it is adapted to receive a portion of the locking
member 43. As shown, the slot 56 may be positioned at or proximate
to the proximal end 55, but it is also contemplated that it may
alternatively be positioned elsewhere along the stem 54, provided
that the base member 41 is correspondingly adapted. The stem 54 and
slot 56 are adapted to fit within the cavity 46 of the base member
41 such that both slots 49, 56 are aligned to each receive a
portion and together receive the whole of the locking member
43.
[0057] The locking member 43 is a resilient spring member having at
least a first and a second configuration (not shown) and is adapted
to be received within both slots 49, 56 to mechanically join the
metatarsal articulation member 42 with the base member 41. In some
embodiments, the metatarsal articulation member 42 and the base
member 41 are permanently joined, and as such are effectively a
single component of the implantable device. As shown, the locking
member 43 is non-continuous and has a generally circular
cross-section. However, it is also contemplated that the locking
member 43 may alternatively be continuous, have an different
cross-section, or combinations thereof, provided that other
elements (including, but not limited to the slots 49, 56) of the
metatarsal component 39 are correspondingly adapted. For example, a
locking member 43 could have a cross-section selected from
generally elliptical, square, triangular, or other suitable
cross-section. In some embodiments, the locking member 43 may
comprise a resilient material suitable for surgical implants.
[0058] In some embodiments of assembly, the locking member 43 is
flexed from a first to a second configuration upon insertion
through the partially shared second ends 45, 48 of the base member
41 and cavity 46; remains in the second configuration as it is
advanced along the cavity 46 towards the first end 47; and upon
encountering the slot 49 flexes from the second to the first
configuration as it is received within the slot 49. Alternatively,
it is contemplated that the locking member 43 may flex from the
second to an intermediate third configuration as it is received
within the slot 49.
[0059] In some embodiments of assembly, a portion of the locking
member 43 is received within the slot 56 of the metatarsal
articulating member 42; the stem 54 of said articulating member 42
is inserted through the shared ends 45, 48 of the base member 41
and cavity 46 as the locking member 43 flexes from a first to a
second configuration; the locking member 43 remains in the second
configuration as it and the stem 54 are advanced along the cavity
46 towards the first end 47; and upon encountering the slot 49 of
the base member 41, the locking member 43 flexes from the second to
the first configuration as it is received within the slot 49.
Alternatively, it is contemplated that the locking member 43 may
flex from the second to an intermediate third configuration as it
is received within the slot 49.
[0060] A further illustrated in FIG. 7, the base member 44 of the
phalanx component 40 is conical or tapered and has a generally
circular cross-section. However, it is also contemplated that a
base member 44 may alternatively be non-conical or non-tapered,
have another suitable cross-section, or combinations thereof,
provided that other elements of the phalanx component 40 are also
adapted to fit such alternatives. For example, a base member 44 may
have a cross-section selected from generally elliptical, square,
triangular, or other suitable shape. The base member 44 comprises a
continuous first end 58, a non-continuous second end 59, and a
cavity 60 for receiving a portion of the phalanx articulation
member 45. The cavity 60 comprises a first end 61 recessed within
the base member 44, a second end 62 that is partially shared with
the second end 59 of the base member 44, and a peripheral slot 63
for receiving a portion of the locking member 46. As shown, the
cavity 60 is generally conical or tapered and has a generally
circular cross-section. However, it is also contemplated that the
cavity 60 may alternatively be non-conical or non-tapered, have
another suitable cross-section, or combinations thereof, provided
that other elements of the phalanx component 40 are also adapted to
fit such alternatives. For example, a cavity 60 may have a
cross-section selected from generally elliptical, square,
triangular, or other suitable shape. The slot 63 is integrated with
and formed around all or a portion of the cavity 60 in a direction
away from a longitudinal axis 64 of the base member 44. As shown,
the slot 63 may be positioned at or proximate to the first end 61,
but it is also contemplated that it may alternatively be positioned
elsewhere along the cavity 60, provided that the phalanx
articulation member 45 is correspondingly adapted. Moreover, it is
also contemplated that the first end 58 of the base member 44 may
alternatively be non-continuous and partially shared with the first
end 61 of the cavity 60.
[0061] The articulation member 45 of the phalanx component 40
comprises a head portion 65, a stem 68, and an integral slot 70.
The head portion 65 comprises a substantially concave bearing
surface 66 and a distal surface 67 opposite thereto. As shown, the
distal surface 67 is generally planar, but it is also contemplated
that it could be non-planar. The bearing surface 66 is adapted to
emulate the general shape and function of the proximal portion of
the proximal phalanx bone within a metatarsophalangeal joint. The
stem 68 protrudes from the center (not labeled) of the distal
surface 67, terminates at a distal end 69, and is adapted to be
received within the cavity 60 of the base member 44. When so
received, the distal surface 67 abuts the second end 59 of the base
member 44. It is also contemplated that the distal surface 67 could
be spaced from the second end 59 when so received. As shown, the
stem 68 is generally conical or tapered and has a generally
circular cross-section. However, it is also contemplated that the
stem 68 may alternatively be non-conical or non-tapered, have
another suitable cross-section, or combinations thereof, provided
that other elements of the phalanx component 40 are also adapted to
fit such alternatives. For example, a stem 68 may have a
cross-section selected from generally elliptical, square,
triangular, or other suitable shape. The slot 70 is integrated with
and formed around all or a portion of the stem 68 in a direction
towards a longitudinal axis 71 of the phalanx articulation member
45, and it is adapted to receive a portion of the locking member
46. As shown, the slot 70 may be positioned at or proximate to the
distal end 69, but it is also contemplated that it may
alternatively be positioned elsewhere along the stem 68, provided
that the base member 44 is correspondingly adapted. The stem 68 and
slot 70 are adapted to fit within the cavity 60 of the base member
44 such that both slots 63, 70 are aligned to each receive a
portion and together receive the whole of the locking member
46.
[0062] The locking member 46 is a resilient spring member having at
least a first and a second configuration (not shown) and is adapted
to be received within both slots 63, 70 to mechanically join the
phalanx articulation member 45 with the base member 44. In some
embodiments, the phalanx articulation member 45 and the base member
44 are permanently joined, and as such are effectively a single
component of the implantable device. As shown, the locking member
46 is non-continuous and has a generally circular cross-section.
However, it is also contemplated that the locking member 46 may
alternatively be continuous, have an different cross-section, or
combinations thereof, provided that other elements (including, but
not limited to the slots 63, 70) of the phalanx component 40 are
correspondingly adapted. For example, a locking member 46 could
have a cross-section selected from generally elliptical, square,
triangular, or other suitable cross-section. In some embodiments,
the locking member 46 may comprise a resilient material suitable
for surgical implants.
[0063] In some embodiments of assembly, the locking member 46 is
flexed from a first to a second configuration upon insertion
through the partially shared second ends 59, 62 of the base member
44 and cavity 60; remains in the second configuration as it is
advanced along the cavity 60 towards the first end 61; and upon
encountering the slot 63 flexes from the second to the first
configuration as it is received within the slot 63. Alternatively,
it is contemplated that the locking member 46 may flex from the
second to an intermediate third configuration as it is received
within the slot 63.
[0064] In some embodiments of assembly, a portion of the locking
member 46 is received within the slot 70 of the phalanx
articulating member 45; the stem 68 of said articulating member 45
is inserted through the shared ends 59, 62 of the base member 44
and cavity 60 as the locking member 46 flexes from a first to a
second configuration; the locking member 46 remains in the second
configuration as it and the stem 68 are advanced along the cavity
60 towards the first end 61; and upon encountering the slot 63 of
the base member 44, the locking member 46 flexes from the second to
the first configuration as it is received within the slot 63.
Alternatively, it is contemplated that the locking member 46 may
flex from the second to an intermediate third configuration as it
is received within the slot 63.
[0065] Referring to FIGS. 8-10, illustrated is another example of a
two-component implant 72 that comprises a metatarsal component 73
and a phalanx component 74. The metatarsal component 73 is designed
to be implanted into the distal end of a resected metatarsal bone
to replace all or a portion of the metatarsal head and function as
the metatarsal component of the metatarsophalangeal joint. The
metatarsal component 73 comprises a base member 75, a metatarsal
articulation member 76, and a locking member 77. The base member 75
may be of any suitable length and dimension to allow for fixation
within the metatarsal bone, and may be fixed by any medically
suitable means. In some embodiments, it is designed to be implanted
in approximately one third of the length of the metatarsal bone. In
some embodiments, the base member 75 is designed to be fixed by
tension on the interior cavity of the resected bone.
[0066] The phalanx component 74 is designed to be implanted into
the proximal end of a resected proximal phalanx bone to replace all
or a portion of the proximal end of the proximal phalanx and
function as the phalanx component of the metatarsophalangeal joint.
The phalanx component 74 comprises a base member 78, a phalanx
articulation member 79, and a locking member 80. The base member 78
may be of any suitable length and dimension to allow for fixation
within the phalanx bone, and may be fixed by any medically suitable
means. In some embodiments, it is designed to be implanted in
approximately half of the length of the phalanx bone. In some
embodiments, the base member 78 is designed to be fixed by tension
on the interior cavity of the resected bone.
[0067] In some embodiments, one or both of the metatarsal component
73 and the phalanx component 74 are implanted into the human foot
to replace all or a portion of the metatarsophalangeal joint. In
some embodiments, one or both components 73, 74 may be implanted in
a primary resectional arthroplasty procedure, in a revision
arthroplasty procedure performed to replace or compensate for a
failed implant, or combinations thereof. In some embodiments, one
or both components 73, 74 are implanted in a revision arthroplasty
procedure. In some embodiments, each component 73, 74 implanted may
be selected from small, medium, or large sizes as necessary to
approximate the anatomy of the subject. In some embodiments, the
components 73, 74 may comprise one or more dimensions set forth in
Table 3. In some embodiments, each component 73, 74 and elements
thereof may be customized to the anatomy of the subject.
[0068] As further illustrated in FIG. 9, the base member 75 of the
metatarsal component 73 comprises primary 81 and secondary 82 body
portions. The primary body portion 81 is conical or tapered and has
a generally circular cross-section. However, it is also
contemplated that the primary body portion 81 may alternatively be
non-conical or non-tapered, have another suitable cross-section, or
combinations thereof, provided that other elements of the
metatarsal component 73 are also adapted to fit such alternatives.
For example, a primary body portion 81 may have a cross-section
selected from generally elliptical, square, triangular, or other
suitable shape. The secondary body portion 82 comprises one or more
flanges peripherally positioned around the primary body portion 81.
As shown, the secondary body portion 82 comprises four flanges
equidistantly positioned around the periphery of the primary body
portion 81. Each of said flanges has a generally triangular
cross-section, a length approximately two-thirds that of the
primary body portion 81, one end (not labeled) positioned at the
second end 83 of the base member 75, and runs longitudinally along
the primary body portion 81. However, it is contemplated that the
secondary body portion 82 may have fewer or more flanges, that the
flanges may have another suitable cross-section (for example,
generally elliptical, square, or other suitable shape), that the
flanges may have another suitable length, that the flanges may be
suitably spaced or positioned in a different manner, and
combinations thereof. In some embodiments, the secondary body
portion 82 may be a resilient spring member adapted to be received
within the interior cavity of a resected bone, wherein upon
insertion into the cavity, the secondary body portion 82 flexes
from a first to a second configuration (not shown) that exerts
sufficient tension on the bone cavity to fix the base member 75. In
some embodiments, the secondary body portion 82 may comprise a
resilient material suitable for surgical implants.
[0069] The base member 75 comprises a continuous first end 84, a
non-continuous second end 83, and a cavity 85 for receiving a
portion of the metatarsal articulation member 76. The cavity 85
comprises a first end 86 recessed within the base member 75, a
second end 87 that is partially shared with the second end 83 of
the base member 75, and a peripheral slot 88 for receiving a
portion of the locking member 77. As shown, the cavity 85 is
generally conical or tapered and has a generally circular
cross-section. However, it is also contemplated that the cavity 85
may alternatively be non-conical or non-tapered, have another
suitable cross-section, or combinations thereof, provided that
other elements of the metatarsal component 73 are also adapted to
fit such alternatives. For example, a cavity 85 may have a
cross-section selected from generally elliptical, square,
triangular, or other suitable shape. The slot 88 is integrated with
and formed around all or a portion of the cavity 85 in a direction
away from a longitudinal axis 89 of the base member 75. As shown,
the slot 88 may be positioned at or proximate to the first end 86,
but it is also contemplated that it may alternatively be positioned
elsewhere along the cavity 85, provided that the metatarsal
articulation member 76 is correspondingly adapted. Moreover, it is
also contemplated that the first end 84 of the base member 75 may
alternatively be non-continuous and partially shared with the first
end 86 of the cavity 85.
[0070] The articulation member 76 of the metatarsal component 73
comprises a head portion 90, a stem 93, and an integral slot 95.
The head portion 90 comprises a substantially convex bearing
surface 91 and a proximal surface 92 opposite thereto. As shown,
the proximal surface 92 is generally planar, but it is also
contemplated that it could be non-planar. The bearing surface 91 is
adapted to emulate the general shape and function of the head
portion of the metatarsal bone within a metatarsophalangeal joint.
The stem 93 protrudes from the center (not labeled) of the proximal
surface 92, terminates at a proximal end 94, and is adapted to be
received within the cavity 85 of the base member 75. When so
received, the proximal surface 92 abuts the second end 83 of the
base member 75. It is also contemplated that the proximal surface
92 could be spaced from the second end 83 when so received. As
shown, the stem 93 is generally conical or tapered and has a
generally circular cross-section. However, it is also contemplated
that the stem 93 may alternatively be non-conical or non-tapered,
have another suitable cross-section, or combinations thereof,
provided that other elements of the metatarsal component 73 are
also adapted to fit such alternatives. For example, a stem 93 may
have a cross-section selected from generally elliptical, square,
triangular, or other suitable shape. The slot 95 is integrated with
and formed in a direction towards a longitudinal axis 96 of the
metatarsal articulation member 76 around all or a portion of the
stem 93, and it is adapted to receive a portion of the locking
member 77. As shown, the slot 95 may be positioned at or proximate
to the proximal end 94, but it is also contemplated that it may
alternatively be positioned elsewhere along the stem 93, provided
that the base member 75 is correspondingly adapted. The stem 93 and
slot 95 are adapted to fit within the cavity 85 of the base member
75 such that both slots 88, 95 are aligned to each receive a
portion and together receive the whole of the locking member
77.
[0071] The locking member 77 is a resilient spring member having at
least a first and a second configuration (not shown) and is adapted
to be received within both slots 88, 95 to mechanically join the
metatarsal articulation member 76 with the base member 75. In some
embodiments, the metatarsal articulation member 76 and the base
member 75 are permanently joined, and as such are effectively a
single component of the implantable device. As shown, the locking
member 77 is non-continuous and has a generally circular
cross-section. However, it is also contemplated that the locking
member 77 may alternatively be continuous, have a different
cross-section, or combinations thereof, provided that other
elements (including, but not limited to the slots 88, 95) of the
metatarsal component 76 are correspondingly adapted. For example, a
locking member 77 could have a cross-section selected from
generally elliptical, square, triangular, or other suitable
cross-section. In some embodiments, the locking member 77 may
comprise a resilient material suitable for surgical implants.
[0072] In some embodiments of assembly, the locking member 77 is
flexed from a first to a second configuration upon insertion
through the partially shared second ends 83, 87 of the base member
75 and cavity 85; remains in the second configuration as it is
advanced along the cavity 85 towards the first end 86; and upon
encountering the slot 88 flexes from the second to the first
configuration as it is received within the slot 88. Alternatively,
it is contemplated that the locking member 77 may flex from the
second to an intermediate third configuration as it is received
within the slot 88.
[0073] In some embodiments of assembly, a portion of the locking
member 77 is received within the slot 95 of the metatarsal
articulating member 76; the stem 93 of said articulating member 76
is inserted through the shared ends 83, 87 of the base member 75
and cavity 85 as the locking member 77 flexes from a first to a
second configuration; the locking member 77 remains in the second
configuration as it and the stem 93 are advanced along the cavity
85 towards the first end 86; and upon encountering the slot 88 of
the base member 75, the locking member 77 flexes from the second to
the first configuration as it is received within the slot 88.
Alternatively, it is contemplated that the locking member 77 may
flex from the second to an intermediate third configuration as it
is received within the slot 88.
[0074] As further illustrated in FIG. 10, the base member 78 of the
phalanx component 74 comprises primary 97 and secondary body 98
portions. The primary body portion 97 is conical or tapered and has
a generally circular cross-section. However, it is also
contemplated that the primary body portion 97 may alternatively be
non-conical or non-tapered, have another suitable cross-section, or
combinations thereof, provided that other elements of the phalanx
component 74 are also adapted to fit such alternatives. For
example, a primary body portion 97 may have a cross-section
selected from generally elliptical, square, triangular, or other
suitable shape. The secondary body portion 98 comprises one or more
flanges peripherally positioned around the primary body portion 97.
As shown, the secondary body portion 98 comprises four flanges
equidistantly positioned around the periphery of the primary body
portion 97. Each of said flanges has a generally triangular
cross-section, a length approximately two-thirds that of the
primary body portion 97, one end (not labeled) positioned at the
second end 99 of the base member 78, and runs longitudinally along
the primary body portion 97. However, it is contemplated that the
secondary body portion 98 may have fewer or more flanges, that the
flanges may have another suitable cross-section (for example,
generally elliptical, square, or other suitable shape), that the
flanges may have another suitable length, that the flanges may be
suitably spaced or positioned in a different manner, and
combinations thereof. In some embodiments, the secondary body
portion 98 may be a resilient spring member adapted to be received
within the interior cavity of a resected bone, wherein upon
insertion into the cavity, the secondary body portion 98 flexes
from a first to a second configuration (not shown) that exerts
sufficient tension on the bone cavity to fix the base member 78. In
some embodiments, the secondary body portion 98 may comprise a
resilient material suitable for surgical implants.
[0075] The base member 78 comprises a continuous first end 100, a
non-continuous second end 99, and a cavity 101 for receiving a
portion of the phalanx articulation member 79. The cavity 101
comprises a first end 102 recessed within the base member 78, a
second end 103 that is partially shared with the second end 99 of
the base member 78, and a peripheral slot 104 for receiving a
portion of the locking member 80. As shown, the cavity 101 is
generally conical or tapered and has a generally circular
cross-section. However, it is also contemplated that the cavity 101
may alternatively be non-conical or non-tapered, have another
suitable cross-section, or combinations thereof, provided that
other elements of the phalanx component 74 are also adapted to fit
such alternatives. For example, a cavity 101 may have a
cross-section selected from generally elliptical, square,
triangular, or other suitable shape. The slot 104 is integrated
with and formed around all or a portion of the cavity 101 in a
direction away from a longitudinal axis 105 of the base member 78.
As shown, the slot 104 may be positioned at or proximate to the
first end 102, but it is also contemplated that it may
alternatively be positioned elsewhere along the cavity 101,
provided that the phalanx articulation member 79 is correspondingly
adapted. Moreover, it is also contemplated that the first end 100
of the base member 78 may alternatively be non-continuous and
partially shared with the first end 102 of the cavity 101.
[0076] The articulation member 79 of the phalanx component 74
comprises a head portion 106, a stem 109, and an integral slot 111.
The head portion 106 comprises a substantially concave bearing
surface 107 and a distal surface 108 opposite thereto. As shown,
the distal surface 108 is generally planar, but it is also
contemplated that it could be non-planar. The bearing surface 107
is adapted to emulate the general shape and function of the
proximal portion of the proximal phalanx bone within a
metatarsophalangeal joint. The stem 109 protrudes from the center
(not labeled) of the distal surface 108, terminates at a distal end
110, and is adapted to be received within the cavity 101 of the
base member 78. When so received, the distal surface 108 abuts the
second end 99 of the base member 78. It is also contemplated that
the distal surface 108 could be spaced from the second end 99 when
so received. As shown, the stem 109 is generally conical or tapered
and has a generally circular cross-section. However, it is also
contemplated that the stem 109 may alternatively be non-conical or
non-tapered, have another suitable cross-section, or combinations
thereof, provided that other elements of the phalanx component 74
are also adapted to fit such alternatives. For example, a stem 109
may have a cross-section selected from generally elliptical,
square, triangular, or other suitable shape. The slot 111 is
integrated with and formed around all or a portion of the stem 109
in a direction towards a longitudinal axis 112 of the phalanx
articulation member 79, and it is adapted to receive a portion of
the locking member 80. As shown, the slot 111 may be positioned at
or proximate to the distal end 110, but it is also contemplated
that it may alternatively be positioned elsewhere along the stem
109, provided that the base member 78 is correspondingly adapted.
The stem 109 and slot 111 are adapted to fit within the cavity 101
of the base member 78 such that both slots 104, 111 are aligned to
each receive a portion and together receive the whole of the
locking member 80.
[0077] The locking member 80 is a resilient spring member having at
least a first and a second configuration (not shown) and is adapted
to be received within both slots 104, 111 to mechanically join the
phalanx articulation member 79 with the base member 78. In some
embodiments, the phalanx articulation member 79 and the base member
78 are permanently joined, and as such are effectively a single
component of the implantable device. As shown, the locking member
80 is non-continuous and has a generally circular cross-section.
However, it is also contemplated that the locking member 80 may
alternatively be continuous, have an different cross-section, or
combinations thereof, provided that other elements (including, but
not limited to the slots 104, 111) of the phalanx component 74 are
correspondingly adapted. For example, a locking member 80 could
have a cross-section selected from generally elliptical, square,
triangular, or other suitable cross-section. In some embodiments,
the locking member 80 may comprise a resilient material suitable
for surgical implants.
[0078] In some embodiments of assembly, the locking member 80 is
flexed from a first to a second configuration upon insertion
through the partially shared second ends 99, 103 of the base member
78 and cavity 101; remains in the second configuration as it is
advanced along the cavity 101 towards the first end 102; and upon
encountering the slot 104 flexes from the second to the first
configuration as it is received within the slot 104. Alternatively,
it is contemplated that the locking member 80 may flex from the
second to an intermediate third configuration as it is received
within the slot 104.
[0079] In some embodiments of assembly, a portion of the locking
member 80 is received within the slot 111 of the phalanx
articulating member 79; the stem 109 of said articulating member 79
is inserted through the shared ends 99, 103 of the base member 78
and cavity 101 as the locking member 80 flexes from a first to a
second configuration; the locking member 80 remains in the second
configuration as it and the stem 109 are advanced along the cavity
101 towards the first end 102; and upon encountering the slot 104
of the base member 78, the locking member 80 flexes from the second
to the first configuration as it is received within the slot 104.
Alternatively, it is contemplated that the locking member 80 may
flex from the second to an intermediate third configuration as it
is received within the slot 104.
[0080] Referring to FIGS. 11-19, illustrated are various examples
of implantable devices of the invention which are designed to
replace all or a portion of a metatarsophalangeal joint. Such
devices comprise one or more of: (i) a metatarsal component for
surgical implantation into the distal end of a metatarsal bone,
comprising a metatarsal articulation member comprising a
substantially convex bearing surface and a locking member; and a
base member adapted to be fixed within the metatarsal bone, the
base member comprising a cavity adapted to receive the locking
member; wherein when the locking member is received by the cavity,
the metatarsal articulation member is mechanically joined to the
base member; and (ii) a phalanx component for surgical implantation
into the proximal end of a proximal phalanx bone, comprising a
phalanx articulation member comprising a substantially concave
bearing surface and a locking member; and a base member adapted to
be fixed within the phalanx bone, the base member comprising a
cavity adapted to receive the locking member; wherein when the
locking member is received by the cavity, the phalanx articulation
member is mechanically joined to the base member.
[0081] In those embodiment wherein one of the components is
implanted, the chosen component is adapted to cooperatively engage
with and move with respect to either the proximal end of the
proximal phalanx bone or the distal end of the metatarsal bone. In
those embodiments wherein both of the components are implanted, the
metatarsal component and the phalanx component are adapted to
cooperatively engage such that the metatarsal articulation member
and the phalanx articulation member move with respect to each other
and collectively serve as a prosthetic metatarsophalangeal
joint.
[0082] Referring to FIG. 11, illustrated is one example of a
two-component implant device 113 comprising a metatarsal component
114 and a phalanx component 115. The metatarsal component 114 is
designed to be implanted into the distal end of a resected
metatarsal bone to replace all or a portion of the metatarsal head
and function as the metatarsal component of the metatarsophalangeal
joint. The metatarsal component 114 comprises a base member 116 and
a metatarsal articulation member 117. The base member 116 may be of
any suitable length and dimension to allow for fixation within the
metatarsal bone, and may be fixed by any medically suitable means.
In some embodiments, the base member 116 is designed to be
implanted in approximately one third of the length of the
metatarsal bone. In some embodiments, it is designed to be fixed by
tension on the interior cavity of the resected bone.
[0083] The phalanx component 115 is designed to be implanted into
the proximal end of a resected proximal phalanx bone to replace all
or a portion of the proximal end of the proximal phalanx and
function as the phalanx component of the metatarsophalangeal joint.
The phalanx component 115 comprises a base member 118 and a phalanx
articulation member 119. The base member 118 may be of any suitable
length and dimension to allow for fixation within the phalanx bone,
and may be fixed by any medically suitable means. In some
embodiments, the base member 118 is designed to be implanted in
approximately half of the length of the phalanx bone. In some
embodiments, it is designed to be fixed by tension on the interior
cavity of the resected bone.
[0084] In some embodiments, one or both of the metatarsal component
114 and the phalanx component 115 are implanted into the human foot
to replace all or a portion of the metatarsophalangeal joint. In
some embodiments, one or both components 114, 115 may be implanted
in a primary resectional arthroplasty procedure, in a revision
arthroplasty procedure performed to replace or compensate for a
failed implant, or combinations thereof. In some embodiments, one
or both components 114, 115 are implanted in a revision
arthroplasty procedure. In some embodiments, each component 114,
115 implanted may be selected from small, medium, or large sizes as
necessary to approximate the anatomy of the subject. In some
embodiments, the components 114, 115 may comprise one or more
dimensions set forth in Table 4. In some embodiments, each
component 114, 115 and elements thereof may be customized to the
anatomy of the subject.
TABLE-US-00004 TABLE 4 Dimension (mm) Metatarsal Base Member Length
22-26 Base Member Outer Diameter Top 7-10 Base Member Outer
Diameter Bottom 5-7 Cavity Length 5-7 Cavity Width 4-5 Slot
Depression Diameter 4 Slot Depression Depth 0.5 Head Portion
Diameter 10-13 Head Portion Height 2 Phalanx Base Member Length
18-22 Base Member Outer Diameter Top 10-13 Base Member Outer
Diameter Bottom 6-7 Cavity Length 8-11 Cavity Width 4-5 Slot
Depression Diameter 5 Slot Depression Depth 0.5 Head Portion
Diameter 10-13 Head Portion Depth 2
[0085] A further illustrated in FIG. 12, the base member 116 of the
metatarsal component 114 comprises primary 120 and secondary 121
body portions. The primary body portion 120 is conical or tapered
and has a generally circular cross-section. However, it is also
contemplated that the primary body portion 120 may alternatively be
non-conical or non-tapered, have another suitable cross-section, or
combinations thereof, provided that other elements of the
metatarsal component 114 are also adapted to fit such alternatives.
For example, a primary body portion 120 may have a cross-section
selected from generally elliptical, square, triangular, or other
suitable shape. The secondary body portion 121 comprises one or
more flanges peripherally positioned around the primary body
portion 120. As shown, the secondary body portion 121 comprises
four flanges equidistantly positioned around the periphery of the
primary body portion 120. Each of said flanges has a generally
triangular cross-section, a length approximately half that of the
primary body portion 120, one end (not labeled) positioned at the
second end 123 of the base member 116, and runs longitudinally
along the primary body portion 120. However, it is contemplated
that the secondary body portion 121 may have fewer or more flanges,
that the flanges may have another suitable cross-section (for
example, generally elliptical, square, or other suitable shape),
that the flanges may have another suitable length, that the flanges
may be suitably spaced or positioned in a different manner, and
combinations thereof. In some embodiments, the secondary body
portion 121 may be a resilient spring member adapted to be received
within the interior cavity of a resected bone, wherein upon
insertion into the cavity, the secondary body portion 121 flexes
from a first to a second configuration (not shown) that exerts
sufficient tension on the cavity to fix the base member 116. In
some embodiments, the secondary body portion 121 may comprise a
resilient material suitable for surgical implants.
[0086] The base member 116 comprises a continuous first end 122, a
non-continuous second end 123, and a cavity 124 for receiving a
portion of the metatarsal articulation member 117. The cavity 124
comprises a first end 125 recessed within the base member 116, a
second end 126 that is partially shared with the second end 123 of
the base member 116, and a slot 127 for receiving a portion of a
locking member 131. As shown, the cavity 124 has a generally
rectangular cross-section. However, it is also contemplated that
the cavity 124 may alternatively have another suitable
cross-section, provided that other elements of the metatarsal
component 114 are also adapted to fit such alternatives. For
example, a cavity 124 may have a cross-section selected from
generally elliptical, square, or other suitable shape. As shown,
the second end 126 of the cavity 124 is generally rectangular in
shape. However, it is also contemplated that it may have another
suitable shape, provided that other elements of the metatarsal
component 114 are also adapted to fit such alternatives. The slot
127 is integrated with the first end 125 and formed in a direction
towards the first end 122 of the base member 116. As shown, the
slot 127 may be positioned at or proximate to the center (not
shown) of the first end 125, but it is also contemplated that it
may alternatively be positioned elsewhere on the first end 125,
provided that the metatarsal articulation member 117 is
correspondingly adapted.
[0087] The articulation member 117 of the metatarsal component 114
comprises a head portion 128 and a locking member 131. The head
portion 128 comprises a substantially convex bearing surface 129
and a proximal surface 130 opposite thereto. As shown, the proximal
surface 130 is generally planar, but it is also contemplated that
it could be non-planar. The bearing surface 129 is adapted to
emulate the general shape and function of the head portion of the
metatarsal bone within a metatarsophalangeal joint. The locking
member 131 protrudes proximally from the center (not labeled) of
the proximal surface 130, terminates at a proximal end 132, and is
adapted to be received within the cavity 124 of the base member
116. When so received, the proximal surface 130 abuts the second
end 123 of the base member 116, and the proximal end 132 is locked
within the slot 127.
[0088] The locking member 131 comprises a neck portion 133 abutting
the proximal surface 130 of the metatarsal articulation member 117,
a body portion 134 positioned between the neck portion 133 and the
proximal end 132, and the proximal end 132. As shown, each of the
neck portion 133 and body portion 134 has a generally rectangular
cross-section, wherein the rectangular cross-section of the neck
portion 133 has at least one of length, width, and height that is
smaller than that of the rectangular cross-section of the body
portion 134. It is, however, contemplated that the neck portion 133
and body portion 134 of a locking member 131 may have another
suitable cross-section, dimension, or combination thereof, provided
that other elements of the metatarsal component 114 are also
adapted to fit such alternatives. For example, the neck portion 133
and body portion 134 could alternatively have a cross-section
selected from generally elliptical, circular, square, or other
suitable shape.
[0089] As shown, the proximal end 132 has a generally circular
cross-section. However, it is also contemplated that the proximal
end 132 may alternatively have another suitable cross-section,
provided that other elements of the metatarsal component 114 are
also adapted to fit such alternatives. For example, a proximal end
132 may have a cross-section selected from generally elliptical,
square, triangular, or other suitable shape. The proximal end 132
is adapted to fit within the slot 127 of the cavity 124 of the base
member 116.
[0090] In some embodiments, at least one of the locking member 131
and the second ends 123, 126 is suitably resilient such that the
locking member 131 may be received within the cavity 124 and the
proximal end 132 received within the slot 127 to mechanically join
the metatarsal articulation member 117 with the base member 116. In
some embodiments, one or more of the locking member 131 and second
ends 123, 126 may comprise a resilient material suitable for
surgical implants.
[0091] In some embodiments, the metatarsal articulation member 117
and the base member 116 are permanently joined, and as such are
effectively a single component of the implantable device. In some
embodiments of assembly, the second ends 123, 126 may be flexed
from a first to a second configuration upon insertion of the
locking member 131 into the cavity 124; remain in the second
configuration as the locking member 131 is advanced within the
cavity 124; and upon the proximal end 132 encountering the slot 127
flexes from the second to the first configuration as the proximal
end 132 is received within the slot 127. Alternatively, it is
contemplated that the second ends 123, 126 may flex from the second
to an intermediate third configuration as the proximal end 132 is
received within the slot 127.
[0092] As further illustrated in FIG. 13, the base member 118 of
the phalanx component 115 comprises primary 135 and secondary 136
body portions. The primary body portion 135 is conical or tapered
and has a generally circular cross-section. However, it is also
contemplated that the primary body portion 135 may alternatively be
non-conical or non-tapered, have another suitable cross-section, or
combinations thereof, provided that other elements of the phalanx
component 115 are also adapted to fit such alternatives. For
example, a primary body portion 135 may have a cross-section
selected from generally elliptical, square, triangular, or other
suitable shape. The secondary body portion 136 comprises one or
more flanges peripherally positioned around the primary body
portion 135. As shown, the secondary body portion 136 comprises
four flanges equidistantly positioned around the periphery of the
primary body portion 135. Each of said flanges has a generally
triangular cross-section, a length approximately half that of the
primary body portion 135, one end (not labeled) positioned at the
second end 138 of the base member 118, and runs longitudinally
along the primary body portion 135. However, it is contemplated
that the secondary body portion 136 may have fewer or more flanges,
that the flanges may have another suitable cross-section (for
example, generally elliptical, square, or other suitable shape),
that the flanges may have another suitable length, that the flanges
may be suitably spaced or positioned in a different manner, and
combinations thereof. In some embodiments, the secondary body
portion 136 may be a resilient spring member adapted to be received
within the interior cavity of a resected bone, wherein upon
insertion into the cavity, the secondary body portion 136 flexes
from a first to a second configuration (not shown) that exerts
sufficient tension on the bone cavity to fix the base member 118.
In some embodiments, the secondary body portion 136 may comprise a
resilient material suitable for surgical implants.
[0093] The base member 118 comprises a continuous first end 137, a
non-continuous second end 138, and a cavity 139 for receiving a
portion of the phalanx articulation member 119. The cavity 139
comprises a first end 140 recessed within the base member 118, a
second end 141 that is partially shared with the second end 138 of
the base member 118, and a slot 142 for receiving a portion of a
locking member 146. As shown, the cavity 139 has a generally
rectangular cross-section. However, it is also contemplated that
the cavity 139 may alternatively have another suitable
cross-section, provided that other elements of the phalanx
component 115 are also adapted to fit such alternatives. For
example, a cavity 139 may have a cross-section selected from
generally elliptical, square, or other suitable shape. As shown,
the second end 140 of the cavity 139 is generally rectangular in
shape. However, it is also contemplated that it may have another
suitable shape, provided that other elements of the phalanx
component 115 are also adapted to fit such alternatives. The slot
142 is integrated with the first end 140 and formed in a direction
towards the first end 137 of the base member 118. As shown, the
slot 142 may be positioned at or proximate to the center (not
shown) of the first end 140, but it is also contemplated that it
may alternatively be positioned elsewhere on the first end 140,
provided that the phalanx articulation member 119 is
correspondingly adapted.
[0094] The articulation member 119 of the phalanx component 115
comprises a head portion 143 and a locking member 146. The head
portion 143 comprises a substantially concave bearing surface 144
and a distal surface 145 opposite thereto. As shown, the distal
surface 145 is generally planar, but it is also contemplated that
it could be non-planar. The bearing surface 144 is adapted to
emulate the general shape and function of the proximal portion of
the proximal phalanx bone within a metatarsophalangeal joint. The
locking member 146 protrudes distally from the center (not labeled)
of the distal surface 145, terminates at a distal end 147, and is
adapted to be received within the cavity 139 of the base member
118. When so received, the distal surface 145 abuts the second end
138 of the base member 118, and the distal end 147 is locked within
the slot 142.
[0095] The locking member 146 comprises a neck portion 148 abutting
the distal surface 145 of the phalanx articulation member 119, a
body portion 149 positioned between the neck portion 148 and the
distal end 147, and the distal end 147. As shown, each of the neck
portion 148 and body portion 149 has a generally rectangular
cross-section, wherein the rectangular cross-section of the neck
portion 148 has at least one of length, width, and height that is
smaller than that of the rectangular cross-section of the body
portion 149. It is, however, contemplated that the neck portion 148
and body portion 149 of a locking member 146 may have another
suitable cross-section, dimension, or combination thereof, provided
that other elements of the phalanx component 115 are also adapted
to fit such alternatives. For example, the neck portion 148 and
body portion 149 could alternatively have a cross-section selected
from generally elliptical, circular, square, or other suitable
shape.
[0096] As shown, the distal end 147 has a generally circular
cross-section. However, it is also contemplated that the distal end
147 may alternatively have another suitable cross-section, provided
that other elements of the phalanx component 115 are also adapted
to fit such alternatives. For example, a distal end 147 may have a
cross-section selected from generally elliptical, square,
triangular, or other suitable shape. The distal end 147 is adapted
to fit within the slot 142 of the cavity 139 of the base member
118.
[0097] In some embodiments, at least one of the locking member 146
and the second ends 138, 141 is suitably flexible such that the
locking member 146 may be received within the cavity 139 and the
distal end 147 received within the slot 142 to mechanically join
the phalanx articulation member 119 with the base member 118. In
some embodiments, one or more of the locking member 146, and the
second ends 138, 141 may comprise a resilient material suitable for
surgical implants.
[0098] In some embodiments, the phalanx articulation member 119 and
the base member 118 are permanently joined, and as such are
effectively a single component of the implantable device. In some
embodiments of operation, the second ends 138, 141 may be flexed
from a first to a second configuration upon insertion of the
locking member 146 into the cavity 139, remain in the second
configuration as the locking member 146 is advanced within the
cavity 139, and upon the distal end 147 encountering the slot 142
flexes from the second to the first configuration as the distal end
147 is received within the slot 142. Alternatively, it is
contemplated that the second ends 138, 141 may flex from the second
to an intermediate third configuration as the distal end 147 is
received within the slot 142.
[0099] Referring to FIGS. 14-16, illustrated is another example of
a two-component implant 150 comprising a metatarsal component 151
and a phalanx component 152. The metatarsal component 151 is
designed to be implanted into the distal end of a resected
metatarsal bone to replace all or a portion of the metatarsal head
and function as the metatarsal component of the metatarsophalangeal
joint. The metatarsal component 151 comprises a base member 153 and
a metatarsal articulation member 154. The base member 153 may be of
any suitable length and dimension to allow for fixation within the
metatarsal bone, and may be fixed by any medically suitable means.
In some embodiments, the base member 153 is designed to be
implanted in approximately one third of the length of the
metatarsal bone. In some embodiments, it may be fixed with bone
cement.
[0100] The phalanx component 152 is designed to be implanted into
the proximal end of a resected proximal phalanx bone to replace all
or a portion of the proximal end of the proximal phalanx and
function as the phalanx component of the metatarsophalangeal joint.
The phalanx component 152 comprises a base member 155 and a phalanx
articulation member 156. The base member 155 may be of any suitable
length and dimension to allow for fixation within the phalanx bone,
and may be fixed by any medically suitable means. In some
embodiments, the base member 155 is designed to be implanted in
approximately half of the length of the phalanx bone. In some
embodiments, it may be fixed with bone cement.
[0101] In some embodiments, one or both of the metatarsal component
151 and the phalanx component 152 are implanted into the human foot
to replace all or a portion of the metatarsophalangeal joint. In
some embodiments, one or both components 151, 152 may be implanted
in a primary resectional arthroplasty procedure, in a revision
arthroplasty procedure performed to replace or compensate for a
failed implant, or combinations thereof. In some embodiments, one
or both components 151, 152 are implanted in a primary resectional
arthroplasty procedure. In some embodiments, each component 151,
152 implanted may be selected from small, medium, or large sizes as
necessary to approximate the anatomy of the subject. In some
embodiments, the components 151, 152 may comprise one or more
dimensions set forth in Table 5. In some embodiments, each
component 151, 152 and elements thereof may be customized to the
anatomy of the subject.
TABLE-US-00005 TABLE 5 Dimension (mm) Metatarsal Base Member Length
22-26 Base Member Outer Diameter Top 7-10 Base Member Outer
Diameter Bottom 7-10 Cavity Length 5-8 Cavity Width 4-5 Slot
Depression Diameter 5 Slot Depression Depth 0.5 Head Portion
Diameter 10-13 Head Portion Height 2 Phalanx Base Member Length
18-22 Base Member Outer Diameter Top 10-13 Base Member Outer
Diameter Bottom 10-13 Cavity Length 8-11 Cavity Width 4-5 Slot
Depression Diameter 5 Slot Depression Depth 0.5 Head Portion
Diameter 10-13 Head Portion Depth 2
[0102] A further illustrated in FIG. 15, the base member 153 of the
metatarsal component 151 is cylindrical and has a generally
circular cross-section. However, it is also contemplated that the
base member 153 may alternatively be non-cylindrical, have another
suitable cross-section, or combinations thereof, provided that
other elements of the metatarsal component 151 are also adapted to
fit such alternatives. For example, a base member 153 may have a
cross-section selected from generally elliptical, square,
triangular, or other suitable shape. The base member 153 comprises
a continuous first end 157, a non-continuous second end 158, and a
cavity 159 for receiving a portion of the metatarsal articulation
member 154. The cavity 159 comprises a first end 160 recessed
within the base member 153, a second end 161 that is partially
shared with the second end 158 of the base member 153, and a slot
162 for receiving a portion of a locking member 166. As shown, the
cavity 159 has a generally rectangular cross-section. However, it
is also contemplated that the cavity 159 may alternatively have
another suitable cross-section, provided that other elements of the
metatarsal component 151 are also adapted to fit such alternatives.
For example, a cavity 159 may have a cross-section selected from
generally elliptical, square, or other suitable shape.
[0103] As shown, the second end 160 of the cavity 159 is generally
rectangular in shape. However, it is also contemplated that it may
have another suitable shape, provided that other elements of the
metatarsal component 151 are also adapted to fit such alternatives.
The slot 162 is integrated with the first end 160 and formed in a
direction towards the first end 157 of the base member 153. As
shown, the slot 162 may be positioned at or proximate to the center
(not shown) of the first end 160, but it is also contemplated that
it may alternatively be positioned elsewhere on the first end 160,
provided that the metatarsal articulation member 154 is
correspondingly adapted.
[0104] The articulation member 154 of the metatarsal component 151
comprises a head portion 163 and a locking member 166. The head
portion 163 comprises a substantially convex bearing surface 164
and a proximal surface 165 opposite thereto. As shown, the proximal
surface 165 is generally planar, but it is also contemplated that
it could be non-planar. The bearing surface 164 is adapted to
emulate the general shape and function of the head portion of the
metatarsal bone within a metatarsophalangeal joint. The locking
member 166 protrudes proximally from the center (not labeled) of
the proximal surface 165, terminates at a proximal end 167, and is
adapted to be received within the cavity 159 of the base member
153. When so received, the proximal surface 165 abuts the second
end 158 of the base member 153, and the proximal end 167 is locked
within the slot 162.
[0105] The locking member 166 comprises a neck portion 168 abutting
the proximal surface 165 of the metatarsal articulation member 154,
a body portion 169 positioned between the neck portion 168 and the
proximal end 167, and the proximal end 167. As shown, each of the
neck portion 168 and body portion 169 has a generally rectangular
cross-section, wherein the rectangular cross-section of the neck
portion 168 has at least one of length, width, and height that is
smaller than that of the rectangular cross-section of the body
portion 169. It is, however, contemplated that the neck portion 168
and body portion 169 of a locking member 166 may have another
suitable cross-section, dimension, or combination thereof, provided
that other elements of the metatarsal component 151 are also
adapted to fit such alternatives. For example, the neck portion 168
and body portion 169 could alternatively have a cross-section
selected from generally elliptical, circular, square, or other
suitable shape.
[0106] As shown, the proximal end 167 has a generally circular
cross-section. However, it is also contemplated that the proximal
end 167 may alternatively have another suitable cross-section,
provided that other elements of the metatarsal component 151 are
also adapted to fit such alternatives. For example, a proximal end
167 may have a cross-section selected from generally elliptical,
square, triangular, or other suitable shape. The proximal end 167
is adapted to fit within the slot 162 of the cavity 159 of the base
member 153.
[0107] In some embodiments, at least one of the locking member 166
and the second ends 158, 161 is suitably flexible such that the
locking member 166 may be received within the cavity 159 and the
proximal end 167 received within the slot 162 to mechanically join
the metatarsal articulation member 154 with the base member 153. In
some embodiments, one or more of the locking member 166 and the
second ends 158, 161 may comprise a resilient material suitable for
surgical implants. In some embodiments, the metatarsal articulation
member 154 and the base member 153 are permanently joined, and as
such are effectively a single component of the implantable device.
In some embodiments of assembly, the second ends 158, 161 may be
flexed from a first to a second configuration upon insertion of the
locking member 166 into the cavity 159; remain in the second
configuration as the locking member 166 is advanced within the
cavity 159; and upon the proximal end 167 encountering the slot 162
flexes from the second to the first configuration as the proximal
end 167 is received within the slot 162. Alternatively, it is
contemplated that the second ends 158, 161 may flex from the second
to an intermediate third configuration as the proximal end 167 is
received within the slot 162.
[0108] A further illustrated in FIG. 16, the base member 155 of the
phalanx component 152 is cylindrical and has a generally circular
cross-section. However, it is also contemplated that the base
member 155 may alternatively be non-cylindrical, have another
suitable cross-section, or combinations thereof, provided that
other elements of the phalanx component 152 are also adapted to fit
such alternatives. For example, a base member 155 may have a
cross-section selected from generally elliptical, square,
triangular, or other suitable shape. The base member 155 comprises
a continuous first end 170, a non-continuous second end 171, and a
cavity 172 for receiving a portion of the phalanx articulation
member 156. The cavity 172 comprises a first end 173 recessed
within the base member 155, a second end 174 that is partially
shared with the second end 171 of the base member 155, and a slot
175 for receiving a portion of a locking member 179. As shown, the
cavity 172 has a generally rectangular cross-section. However, it
is also contemplated that the cavity 172 may alternatively have
another suitable cross-section, provided that other elements of the
phalanx component 152 are also adapted to fit such alternatives.
For example, a cavity 172 may have a cross-section selected from
generally elliptical, square, or other suitable shape. As shown,
the second end 174 of the cavity 172 is generally rectangular in
shape. However, it is also contemplated that it may have another
suitable shape, provided that other elements of the phalanx
component 152 are also adapted to fit such alternatives. The slot
175 is integrated with the first end 173 and formed in a direction
towards the first end 170 of the base member 155. As shown, the
slot 175 may be positioned at or proximate to the center (not
shown) of the first end 173, but it is also contemplated that it
may alternatively be positioned elsewhere on the first end 173,
provided that the phalanx articulation member 156 is
correspondingly adapted.
[0109] The articulation member 156 of the phalanx component 152
comprises a head portion 176 and a locking member 179. The head
portion 176 comprises a substantially concave bearing surface 177
and a distal surface 178 opposite thereto. As shown, the distal
surface 178 is generally planar, but it is also contemplated that
it could be non-planar. The bearing surface 177 is adapted to
emulate the general shape and function of the proximal portion of
the proximal phalanx bone within a metatarsophalangeal joint. The
locking member 179 protrudes distally from the center (not labeled)
of the distal surface 178, terminates at a distal end 180, and is
adapted to be received within the cavity 172 of the base member
155. When so received, the distal surface 178 abuts the second end
171 of the base member 155, and the distal end 180 is locked within
the slot 175.
[0110] The locking member 179 comprises a neck portion 181 abutting
the distal surface 178 of the phalanx articulation member 156, a
body portion 182 positioned between the neck portion 181 and the
distal end 180, and the distal end 180. As shown, each of the neck
portion 181 and body portion 182 has a generally rectangular
cross-section, wherein the rectangular cross-section of the neck
portion 181 has at least one of length, width, and height that is
smaller than that of the rectangular cross-section of the body
portion 182. It is, however, contemplated that the neck portion 181
and body portion 182 of a locking member 179 may have another
suitable cross-section, dimension, or combination thereof, provided
that other elements of the phalanx component 152 are also adapted
to fit such alternatives. For example, the neck portion 181 and
body portion 182 could alternatively have a cross-section selected
from generally elliptical, circular, square, or other suitable
shape.
[0111] As shown, the distal end 180 has a generally circular
cross-section. However, it is also contemplated that the distal end
180 may alternatively have another suitable cross-section, provided
that other elements of the phalanx component 152 are also adapted
to fit such alternatives. For example, a distal end 180 may have a
cross-section selected from generally elliptical, square,
triangular, or other suitable shape. The distal end 180 is adapted
to fit within the slot 175 of the cavity 172 of the base member
155.
[0112] In some embodiments, at least one of the locking member 179
and the second ends 171, 174 is suitably flexible such that the
locking member 179 may be received within the cavity 172 and the
distal end 180 received within the slot 172 to mechanically join
the phalanx articulation member 156 with the base member 155. In
some embodiments, one or more of the locking member 179 and the
second ends 171, 174 may comprise a resilient material suitable for
surgical implants. In some embodiments, the phalanx articulation
member 156 and the base member 155 are permanently joined, and as
such are effectively a single component of the implantable device.
In some embodiments of assembly, the second ends 171, 174 may be
flexed from a first to a second configuration upon insertion of the
locking member 179 into the cavity 172; remain in the second
configuration as the locking member 179 is advanced within the
cavity 172; and upon the distal end 180 encountering the slot 175
flexes from the second to the first configuration as the distal end
180 is received within the slot 175. Alternatively, it is
contemplated that the second ends 171, 174 may flex from the second
to an intermediate third configuration as the distal end 180 is
received within the slot 175.
[0113] Referring to FIGS. 17-19, illustrated is another example of
a two-component device 183 comprising a metatarsal component 184
and a phalanx component 185. The metatarsal component 184 is
designed to be implanted into the distal end of a resected
metatarsal bone to replace all or a portion of the metatarsal head
and function as the metatarsal component of the metatarsophalangeal
joint. The metatarsal component 184 comprises a base member 186 and
a metatarsal articulation member 187. The base member 186 may be of
any suitable length and dimension to allow for fixation within the
metatarsal bone, and may be fixed by any medically suitable means.
In some embodiments, the base member 186 is designed to be
implanted in approximately one third of the length of the
metatarsal bone. In some embodiments, it may be fixed with bone
cement.
[0114] The phalanx component 185 is designed to be implanted into
the proximal end of a resected proximal phalanx bone to replace all
or a portion of the proximal end of the proximal phalanx and
function as the phalanx component of the metatarsophalangeal joint.
The phalanx component 185 comprises a base member 188 and a phalanx
articulation member 189. The base member 188 may be of any suitable
length and dimension to allow for fixation within the phalanx bone,
and may be fixed by any medically suitable means. In some
embodiments, the base member 188 is designed to be implanted in
approximately half of the length of the phalanx bone. In some
embodiments, it may be fixed with bone cement.
[0115] In some embodiments, one or both of the metatarsal component
184 and the phalanx component 185 are implanted into the human foot
to replace all or a portion of the metatarsophalangeal joint. In
some embodiments, one or both components 184, 185 may be implanted
in a primary resectional arthroplasty procedure, in a revision
arthroplasty procedure performed to replace or compensate for a
failed implant, or combinations thereof. In some embodiments, one
or both components 184, 185 are implanted in a revision
arthroplasty procedure. In some embodiments, each component 184,
185 implanted may be selected from small, medium, or large sizes as
necessary to approximate the anatomy of the subject. In some
embodiments, the components 184, 185 may comprise one or more
dimensions set forth in Table 4. In some embodiments, each
component 184, 185 and elements thereof may be customized to the
anatomy of the subject.
[0116] A further illustrated in FIG. 18, the base member 186 of the
metatarsal component 184 is conical or tapered and has a generally
circular cross-section. However, it is also contemplated that the
base member 186 may alternatively be non-conical or non-tapered,
have another suitable cross-section, or combinations thereof,
provided that other elements of the metatarsal component 184 are
also adapted to fit such alternatives. For example, a base member
186 may have a cross-section selected from generally elliptical,
square, triangular, or other suitable shape. The base member 186
comprises a continuous first end 190, a non-continuous second end
191, and a cavity 192 for receiving a portion of the metatarsal
articulation member 187. The cavity 192 comprises a first end 193
recessed within the base member 186, a second end 194 that is
partially shared with the second end 191 of the base member 186,
and a slot 195 for receiving a portion of a locking member 199. As
shown, the cavity 192 has a generally rectangular cross-section.
However, it is also contemplated that the cavity 192 may
alternatively have another suitable cross-section, provided that
other elements of the metatarsal component 184 are also adapted to
fit such alternatives. For example, a cavity 192 may have a
cross-section selected from generally elliptical, square, or other
suitable shape.
[0117] As shown, the second end 194 of the cavity 192 is generally
rectangular in shape. However, it is also contemplated that it may
have another suitable shape, provided that other elements of the
metatarsal component 184 are also adapted to fit such alternatives.
The slot 195 is integrated with the first end 193 and formed in a
direction towards the first end 190 of the base member 186. As
shown, the slot 195 may be positioned at or proximate to the center
(not shown) of the first end 193, but it is also contemplated that
it may alternatively be positioned elsewhere on the first end 193,
provided that the metatarsal articulation member 187 is
correspondingly adapted.
[0118] The articulation member 187 of the metatarsal component 184
comprises a head portion 196 and a locking member 199. The head
portion 196 comprises a substantially convex bearing surface 197
and a proximal surface 198 opposite thereto. As shown, the proximal
surface 198 is generally planar, but it is also contemplated that
it could be non-planar. The bearing surface 197 is adapted to
emulate the general shape and function of the head portion of the
metatarsal bone within a metatarsophalangeal joint. The locking
member 199 protrudes proximally from the center (not labeled) of
the proximal surface 198, terminates at a proximal end 200, and is
adapted to be received within the cavity 192 of the base member
186. When so received, the proximal surface 198 abuts the second
end 191 of the base member 186, and the proximal end 200 is locked
within the slot 195.
[0119] The locking member 199 comprises a neck portion 201 abutting
the proximal surface 198 of the metatarsal articulation member 187,
a body portion 202 positioned between the neck portion 201 and the
proximal end 200, and the proximal end 200. As shown, each of the
neck portion 201 and body portion 202 has a generally rectangular
cross-section, wherein the rectangular cross-section of the neck
portion 201 has at least one of length, width, and height that is
smaller than that of the rectangular cross-section of the body
portion 202. It is, however, contemplated that the neck portion 201
and body portion 202 of a locking member 199 may have another
suitable cross-section, dimension, or combination thereof, provided
that other elements of the metatarsal component 184 are also
adapted to fit such alternatives. For example, the neck portion 201
and body portion 202 could alternatively have a cross-section
selected from generally elliptical, circular, square, or other
suitable shape.
[0120] As shown, the proximal end 200 has a generally circular
cross-section. However, it is also contemplated that the proximal
end 200 may alternatively have another suitable cross-section,
provided that other elements of the metatarsal component 184 are
also adapted to fit such alternatives. For example, a proximal end
200 may have a cross-section selected from generally elliptical,
square, triangular, or other suitable shape. The proximal end 200
is adapted to fit within the slot 195 of the cavity 192 of the base
member 186.
[0121] In some embodiments, at least one of the locking member 199
and the second ends 191, 194 is suitably flexible such that the
locking member 199 may be received within the cavity 192 and the
proximal end 200 received within the slot 195 to mechanically join
the metatarsal articulation member 187 with the base member 186. In
some embodiments, one or more of the locking member 199 and the
second ends 191, 194 may comprise a resilient material suitable for
surgical implants. In some embodiments, the metatarsal articulation
member 187 and the base member 186 are permanently joined, and as
such are effectively a single component of the implantable device.
In some embodiments of assembly, the second ends 191, 194 may be
flexed from a first to a second configuration upon insertion of the
locking member 199 into the cavity 192; remain in the second
configuration as the locking member 199 is advanced within the
cavity 192; and upon the proximal end 200 encountering the slot 195
flexes from the second to the first configuration as the proximal
end 200 is received within the slot 195. Alternatively, it is
contemplated that the second ends 191, 194 may flex from the second
to an intermediate third configuration as the proximal end 200 is
received within the slot 195.
[0122] A further illustrated in FIG. 19, the base member 188 of the
phalanx component 185 is conical or tapered and has a generally
circular cross-section. However, it is also contemplated that the
base member 188 may alternatively be non-conical or non-tapered,
have another suitable cross-section, or combinations thereof,
provided that other elements of the phalanx component 185 are also
adapted to fit such alternatives. For example, a base member 188
may have a cross-section selected from generally elliptical,
square, triangular, or other suitable shape. The base member 188
comprises a continuous first end 203, a non-continuous second end
204, and a cavity 205 for receiving a portion of the phalanx
articulation member 189. The cavity 205 comprises a first end 206
recessed within the base member 188, a second end 207 that is
partially shared with the second end 204 of the base member 188,
and a slot 208 for receiving a portion of a locking member 212. As
shown, the cavity 205 has a generally rectangular cross-section.
However, it is also contemplated that the cavity 205 may
alternatively have another suitable cross-section, provided that
other elements of the phalanx component 185 are also adapted to fit
such alternatives. For example, a cavity 205 may have a
cross-section selected from generally elliptical, square, or other
suitable shape. As shown, the second end 207 of the cavity 205 is
generally rectangular in shape. However, it is also contemplated
that it may have another suitable shape, provided that other
elements of the phalanx component 185 are also adapted to fit such
alternatives. The slot 208 is integrated with the first end 206 and
formed in a direction towards the first end 203 of the base member
188. As shown, the slot 208 may be positioned at or proximate to
the center (not shown) of the first end 206, but it is also
contemplated that it may alternatively be positioned elsewhere on
the first end 206, provided that the phalanx articulation member
189 is correspondingly adapted.
[0123] The articulation member 189 of the phalanx component 185
comprises a head portion 209 and a locking member 212. The head
portion 209 comprises a substantially concave bearing surface 210
and a distal surface 211 opposite thereto. As shown, the distal
surface 211 is generally planar, but it is also contemplated that
it could be non-planar. The bearing surface 210 is adapted to
emulate the general shape and function of the proximal portion of
the proximal phalanx bone within a metatarsophalangeal joint. The
locking member 212 protrudes distally from the center (not labeled)
of the distal surface 211, terminates at a distal end 213, and is
adapted to be received within the cavity 205 of the base member
188. When so received, the distal surface 211 abuts the second end
204 of the base member 188, and the distal end 213 is locked within
the slot 208.
[0124] The locking member 212 comprises a neck portion 214 abutting
the distal surface 211 of the phalanx articulation member 189, a
body portion 215 positioned between the neck portion 214 and the
distal end 213, and the distal end 213. As shown, each of the neck
portion 214 and body portion 215 has a generally rectangular
cross-section, wherein the rectangular cross-section of the neck
portion 214 has at least one of length, width, and height that is
smaller than that of the rectangular cross-section of the body
portion 215. It is, however, contemplated that the neck portion 214
and body portion 215 of a locking member 212 may have another
suitable cross-section, dimension, or combination thereof, provided
that other elements of the phalanx component 185 are also adapted
to fit such alternatives. For example, the neck portion 214 and
body portion 215 could alternatively have a cross-section selected
from generally elliptical, circular, square, or other suitable
shape.
[0125] As shown, the distal end 213 has a generally circular
cross-section. However, it is also contemplated that the distal end
213 may alternatively have another suitable cross-section, provided
that other elements of the phalanx component 185 are also adapted
to fit such alternatives. For example, a distal end 213 may have a
cross-section selected from generally elliptical, square,
triangular, or other suitable shape. The distal end 213 is adapted
to fit within the slot 208 of the cavity 205 of the base member
188.
[0126] In some embodiments, at least one of the locking member 212
and the second ends 204, 207 is suitably flexible such that the
locking member 212 may be received within the cavity 205 and the
distal end 213 received within the slot 208 to mechanically join
the phalanx articulation member 189 with the base member 188. In
some embodiments, one or more of the locking member 212 and the
second ends 204, 207 may comprise a resilient material suitable for
surgical implants. In some embodiments, the phalanx articulation
member 189 and the base member 188 are permanently joined, and as
such are effectively a single component of the implantable device.
In some embodiments of operation, the second ends 204, 207 may be
flexed from a first to a second configuration upon insertion of the
locking member 212 into the cavity 205; remain in the second
configuration as the locking member 212 is advanced within the
cavity 205; and upon the distal end 213 encountering the slot 208
flexes from the second to the first configuration as the distal end
213 is received within the slot 208. Alternatively, it is
contemplated that the second ends 204, 207 may flex from the second
to an intermediate third configuration as the distal end 213 is
received within the slot 208.
[0127] Referring to FIGS. 20-25, illustrated are various examples
of implantable devices of the invention which are designed to
replace all or a portion of a metatarsophalangeal joint. Such
devices comprise one or more of: (i) a metatarsal component for
surgical implantation into the distal end of a metatarsal bone,
comprising a metatarsal articulation member comprising a
substantially convex bearing surface and a cavity adapted to
receive at least a portion of a locking member; a base member
adapted to be fixed within the metatarsal bone; a locking member
adapted to be at least partially received by the cavity; wherein
when the locking member is received within the cavity, the
metatarsal articulation member is mechanically joined to the base
member; and (ii) a phalanx component for surgical implantation into
the proximal end of a proximal phalanx bone, comprising a phalanx
articulation member comprising a substantially convex bearing
surface and a cavity adapted to receive at least a portion of a
locking member; a base member adapted to be fixed within the
phalanx bone; a locking member adapted to be at least partially
received by the cavity; wherein when the locking member is received
within the cavity, the phalanx articulation member is mechanically
joined to the base member.
[0128] In those embodiments wherein one of the components is
implanted, the chosen component is adapted to cooperatively engage
with and move with respect to either the proximal end of the
proximal phalanx bone or the distal end of the metatarsal bone. In
those embodiments wherein both of the components are implanted, the
metatarsal component and the phalanx component are adapted to
cooperatively engage such that the metatarsal articulation member
and the phalanx articulation member move with respect to each other
and collectively serve as a prosthetic metatarsophalangeal
joint.
[0129] Referring to FIG. 20, illustrated is one example of a device
comprising a metatarsal articulation member 216, a phalanx
articulation member 217, a base member 218, and a screw member 219.
The base member 218 is designed to be implanted into the distal end
of a resected metatarsal bone, the proximal end of a resected
proximal phalanx bone, or both. The base member 218 may be of any
suitable length and dimension to allow for fixation within the
metatarsal and phalanx bones, and may be fixed by any medically
suitable means. In some embodiments, the base member 218 is
designed to be implanted in approximately one third of the length
of the metatarsal bone or half of the length of the phalanx bone.
In some embodiments, it is designed to be fixed by tension on the
interior cavity of the resected bone. When the metatarsal-implanted
base member 218 is mechanically joined to the metatarsal
articulation member 216, the device is designed to replace all or a
portion of the metatarsal head and function as the metatarsal
component of the metatarsophalangeal joint. When the
phalanx-implanted base member 218 is mechanically joined to the
phalanx articulation member 217, the device is designed to replace
all or a portion of the proximal end of the proximal phalanx and
function as the phalanx component of the metatarsophalangeal
joint.
[0130] In some embodiments, the device may be implanted into one or
both of the metatarsal and phalanx bones in a primary resectional
arthroplasty procedure, in a revision arthroplasty procedure
performed to replace or compensate for a failed implant, or
combinations thereof. In some embodiments, implantation is by a
revision arthroplasty procedure. In some embodiments, each device
implanted may be selected from small, medium, or large sizes as
necessary to approximate the anatomy of the subject. In some
embodiments, the devices may comprise one or more dimensions set
forth in Table 6. In some embodiments, each device and elements
thereof may be customized to the anatomy of the subject.
TABLE-US-00006 TABLE 6 Dimension Metatarsal and Phalanx (mm) Base
Member Length Metatarsal 22-26 Base Member Length Phalange 18-22
Base Member Head Portion Height 5-6 Base Member Head Portion
Without Flange 9-10 Base Member Head Portion and Flange Width 10-11
Screw Length Metatarsal 22-26 Screw Length Phalange 18-22 Screw
Head Height 2 Screw Head Diameter 9-10 Articulation Member Height
10 (Excluding Bearing Surface) Articulation Member Bearing Surface
16-22 Diameter Bearing Surface Depth 2 Bearing Surface Height 2
[0131] A further illustrated in FIG. 21, the base member 218
comprises a first end 220, a second end 221 comprising a head
portion 222, a body portion 223, and a cavity 224 for receiving the
screw member 219. As shown, the first 220 and second 221 ends are
non-continuous. The cavity 224 is continuous through the base
member 218 from the first end 220 to the second end 221. As shown,
the cavity 224 and body portion 223 are conical or tapered and have
a generally non-continuous cross-section with a generally circular
shape. It is, however, contemplated that the cavity 224 and body
portion 223 could alternatively be non-conical or non-tapered, have
another suitable cross-section, or combinations thereof, provided
that other elements of the device are also adapted to fit such
alternatives. For example, a cross-section could be selected from
generally elliptical, square, or other suitable shape. In some
embodiments, the body portion 223 may be a resilient member adapted
to be received within the interior cavity of a resected bone,
wherein the body portion 223 expands in response to the screw
member 219 being received and advanced within the cavity 224 and
exerts sufficient tension on the bone cavity to fix the base member
218 therein. In some embodiments, the body portion 223 may comprise
a resilient material suitable for surgical implants.
[0132] The head portion 222 has a generally rectangular
cross-section. However, it is also contemplated that a head portion
222 could alternatively have another suitable cross-section,
provided that other elements of the device are also adapted to fit
such alternatives. For example, a head portion 222 could have a
cross-section selected from generally elliptical, square, or other
suitable shape. The head portion 222 comprises a locking member
225. In some embodiments, the locking member 225 comprises a pair
of flanges, each opposably positioned on the exterior of the head
portion 222. As shown, the flanges are positioned at or proximate
to the body portion 223, are perpendicular to a longitudinal axis
226, and have a generally rectangular cross-section with at least
one of length, width, or height that is the same as that of the
cross-section of the head portion 222. It is also contemplated that
the head portion 222 could comprise a locking member 225 with more
than one pair of flanges, that the flanges could be alternatively
positioned, that the flanges could have a different cross-section
or dimension, or combinations thereof, provided that other elements
of the device are also adapted to fit such alternatives. In some
embodiments, the flanges are a locking member 225 adapted to
mechanically join the metatarsal articulation member 216 or the
phalanx articulation member 217 to the base member 218. The head
portion 222 further comprises an interior (female) screw thread 227
along the portion of the cavity 224 formed within the head portion
222, said screw thread 227 adapted to receive a portion of the
screw member 219.
[0133] As shown, the screw member 219 comprises a first end 228, a
second end 229 comprising a head portion 230, and a body portion
231 comprising an external (male) screw thread 232. The screw
thread 232 is adapted to be at least partially received by the
interior screw thread 227 of the base member 218. The screw member
219 is generally cylindrical and has a generally circular
cross-section. However, it is also contemplated that the screw
member 219 could alternatively be non-cylindrical, have an
different cross-section, or combinations thereof, provided that
other elements of the device are correspondingly adapted. For
example, a screw member 219 could be tapered or conical or have a
helical cross-section. The head portion 230 of the screw member 219
has a cross-section larger than that of the body portion 231.
Additionally, the head portion 230 comprises a slot 233 centrally
positioned on the second end 229. As shown, the slot 233 has a
generally rectangular cross-section. However, it is also
contemplated that the slot 233 could alternatively have another
suitable cross-section. The screw member 219 is adapted to be
received within the cavity 224 of the base member 218. When the
screw member 219 is so received, the head portion 230 abuts the
second end 221 of the base member 218. When so received, the
combination of the screw member 219 and base member 218 is adapted
be at least partially received by the metatarsal articulation
member 216, the phalanx articulation member 217, or both and
mechanically joined by the locking member 225.
[0134] As further illustrated in FIG. 22, the metatarsal
articulation member 216 comprises a substantially convex bearing
surface 234 and a proximal surface 235 opposite thereto. As shown,
the proximal surface 235 is generally planar, but it is also
contemplated that it could be non-planar. The bearing surface 234
is adapted to emulate the general shape and function of the head
portion of the metatarsal bone within a metatarsophalangeal joint.
The metatarsal articulation member 216 also comprises a cavity 236
depressed from the center (not labeled) of the proximal surface 235
and that is adapted to receive at least a portion of the
combination of the screw member 219 and base member 218. In some
embodiments, the cavity 236 is adapted to receive at least a
portion of the head portion 222 of the base member 218 and at least
a portion of the head portion 230 of the screw member 219 when the
screw member 219 is received within the cavity 223 of the base
member 218. The cavity 236 of the metatarsal articulation member
216 comprises a distal portion 237 for receiving at least a portion
of the head portion 230 of the screw member 219, a middle portion
238 for receiving the second end 221 and at least a portion of the
head portion 222 of the base member 218, and a proximal portion 239
for receiving at least a portion of the flanges of the locking
member 225. The distal portion 237 of the cavity 236 has a
cross-section that matches that of the head portion 230 of the
screw member 219. As shown, the distal portion 237 has a circular
cross-section. The middle portion 238 of the cavity 236 has a
cross-section that matches that of the second end 221 and at least
a portion of the head portion 222 of the base member 218. As shown,
the middle portion 238 has a rectangular cross-section. The
proximal portion 239 of the cavity 236 comprises at least two
opposing slots adapted to receive at least a portion of the
opposing flanges of the locking member 225. As shown, the slots of
the proximal portion 239 have a rectangular cross-section.
[0135] As also illustrated in FIG. 22, the phalanx articulation
member 217 comprises a substantially concave bearing surface 240
and a distal surface 241 opposite thereto. As shown, the distal
surface 241 is generally planar, but it is also contemplated that
it could be non-planar. The bearing surface 240 is adapted to
emulate the general shape and function of the proximal portion of
the proximal phalanx bone within a metatarsophalangeal joint. The
phalanx articulation member 217 also comprises a cavity 242
depressed from the center (not labeled) of the distal surface 241
and that is adapted to receive at least a portion of the
combination of the screw member 219 and base member 218. In some
embodiments, the cavity 242 is adapted to receive at least a
portion of the head portion 222 of the base member 218 and at least
a portion of the head portion 230 of the screw member 219 when the
screw member 219 is received within the cavity 223 of the base
member 218. The cavity 242 of the phalanx articulation member 217
comprises a proximal portion 243 for receiving at least a portion
of the head portion 230 of the screw member 219, a middle portion
244 for receiving the second end 221 and at least a portion of the
head portion 222 of the base member 218, and a distal portion 245
for receiving at least a portion of the flanges of the locking
member 225. The proximal portion 243 of the cavity 242 has a
cross-section that matches that of the head portion 230 of the
screw member 219. As shown, the distal portion 243 has a circular
cross-section. The middle portion 244 of the cavity 242 has a
cross-section that matches that of the second end 221 and at least
a portion of the head portion 222 of the base member 218. As shown,
the middle portion 244 has a rectangular cross-section. The distal
portion 245 of the cavity 242 comprises at least two opposing slots
adapted to receive at least a portion of the opposing flanges of
the locking member 225. As shown, the slots of the distal portion
245 have a rectangular cross-section.
[0136] In some embodiments, at least a portion of the metatarsal
articulation member 216, at least a portion of the flanges of the
locking member 225, or combinations thereof are suitably flexible
such that the flanges 225 may be received within the proximal
portion 239 of the cavity 236 of the articulation member 216 to
mechanically join the articulation member 216 with the base member
218. In some embodiments, at least a portion of the phalanx
articulation member 217, at least a portion of the flanges of the
locking member 225, or combinations thereof are suitably flexible
such that the flanges may be received within the distal portion 245
of the cavity 242 of the articulation member 217 to mechanically
join the articulation member 217 with the base member 218.
[0137] In some embodiments of assembly, at least the first end 220
and body portion 223 of the base member 218 are first implanted
within the resected portion of the bone. Then the first end 228 of
the screw member 219 is inserted in and, using a tool that fits the
slot 233 of the screw member 219, screwed through the second end
221 and head portion 222 of the base member 218, thereby causing
the body portion 223 of the base member 218 to expand with
sufficient force to fix the base member 218 and screw member 219
within the bone. When so fixed, the head portion 230 of the screw
member 219 abuts the second end 221 of the base member 218. Next,
either the metatarsal articulation member 216 or the phalanx
articulation member 217 is placed over the combined locking head
portion 230, base second end 221, and base head portion 222 in an
orientation allowing the flanges of the locking member 225 to be
received within the slots 239 or 245 of the chosen articulation
member 216 or 217. Finally, sufficient force is applied to the
chosen articulation member 216 or 217 to cause at least a portion
of the articulation member 216 or 217, the locking member 225, or
combinations thereof to resiliently flex from a first to a second
position to allow the flanges to be received within the slots 239
or 245, and then from a second to a first position as the flanges
are received within the slots 239 or 245. Alternatively, it is
contemplated that at least a portion of the articulation member 216
or 217, the locking member 225, or combinations thereof may
resiliently flex from the second to an intermediate third
configuration as the flanges are received within the slots 239 or
245. When the flanges are received within the slots 239 or 245, the
chosen articulation member 216 or 217 is mechanically joined to the
base member 218. In some embodiments, the chosen articulation
member 216 or 217 is permanently joined to the base member 218.
[0138] Referring to FIGS. 23-25, illustrated is one example of a
device comprising a metatarsal articulation member 246, a phalanx
articulation member 247, a base member 248, and a locking member
249. The device may be utilized as a single (hemi) component
implant or as a two-component (total) implant. The base member 248
is designed to be implanted into the distal end of a resected
metatarsal bone, the proximal end of a resected proximal phalanx
bone, or both. The base member 248 may be of any suitable length
and dimension to allow for fixation within the metatarsal and
phalanx bones, and may be fixed by any medically suitable means. In
some embodiments, the base member 248 is designed to be implanted
in approximately one third of the length of the metatarsal bone or
half of the length of the phalanx bone. In some embodiments, it is
designed to be fixed by tension on the interior cavity of the
resected bone. When the metatarsal-implanted base member 248 is
mechanically joined to the metatarsal articulation member 246 with
the locking member 249, the device is designed to replace all or a
portion of the metatarsal head and function as the metatarsal
component of the metatarsophalangeal joint. When the
phalanx-implanted base member 248 is mechanically joined to the
phalanx articulation member 247 with the locking member 249, the
device is designed to replace all or a portion of the proximal end
of the proximal phalanx and function as the phalanx component of
the metatarsophalangeal joint.
[0139] In some embodiments, the device may be implanted into one or
both of the metatarsal and phalanx bones in a primary resectional
arthroplasty procedure, in a revision arthroplasty procedure
performed to replace or compensate for a failed implant, or
combinations thereof. In some embodiments, implantation is by a
revision arthroplasty procedure. In some embodiments, each device
implanted may be selected from small, medium, or large sizes as
necessary to approximate the anatomy of the subject. In some
embodiments, the devices may comprise one or more dimensions set
forth in Table 7. In some embodiments, each device and elements
thereof may be customized to the anatomy of the subject.
TABLE-US-00007 TABLE 7 Dimension Metatarsal and Phalanx (mm) Base
Member Length Metatarsal 22-26 Base Member Length Phalange 18-22
Locking Member Length Metatarsal 22-26 Locking Member Length
Phalange 18-22 Locking Member Head Height 2 Locking Member Head
Diameter 9-10 Articulation Member Height 10 (Excluding Bearing
Surface) Articulation Member Dome Diameter 16-22 Phalanx Bearing
Surface Depth 2 Metatarsal Bearing Surface Height 2
[0140] A further illustrated in FIG. 24, the base member 248
comprises a first end 250, a second end 251 comprising a head
portion 252, a body portion 253, and a cavity 254 for receiving the
locking member 249. As shown, the first 250 and second 251 ends are
non-continuous. The cavity 254 is continuous through the base
member 248 from the first end 250 to the second end 251. As shown,
the cavity 254 and body portion 253 are conical or tapered and have
a generally non-continuous cross-section with a generally circular
shape. It is, however, contemplated that the cavity 254 and body
portion 253 could alternatively be non-conical or non-tapered, have
another suitable cross-section, or combinations thereof, provided
that other elements of the device are also adapted to fit such
alternatives. For example, a cross-section could be selected from
generally elliptical, square, or other suitable shape. In some
embodiments, the body portion 253 may be a resilient member adapted
to be received within the interior cavity of a resected bone,
wherein the body portion 253 expands in response to the locking
member 249 being received and advanced through the cavity 254 and
exerts sufficient tension on the cavity of the bone to fix the base
member 248 therein. In some embodiments, the body portion 253 may
comprise a resilient material suitable for surgical implants.
[0141] The head portion 252 has a generally circular cross-section.
However, it is also contemplated that a head portion 252 could
alternatively have another suitable cross-section, provided that
other elements of the device are also adapted to fit such
alternatives. For example, a head portion 252 could have a
cross-section selected from generally elliptical, square, or other
suitable shape. The head portion 252 also comprises an interior
(female) screw thread 255 along the portion of the cavity 254
formed within the head portion 252, said screw thread 255 adapted
to receive a portion of the locking member 249.
[0142] As shown, the locking member 249 is a screw member
comprising a first end 256, a second end 257 comprising a head
portion 258, and a body portion 259 comprising an external (male)
screw thread 260. The screw thread 260 is adapted to be at least
partially received by the interior screw thread 255 of the base
member 248. The locking member 249 is generally cylindrical and has
a generally circular cross-section. However, it is also
contemplated that the locking member 249 could alternatively be
non-cylindrical, have an different cross-section, or combinations
thereof, provided that other elements of the device are
correspondingly adapted. For example, a locking member 249 could be
tapered or conical or have a helical cross-section. The head
portion 258 of the locking member 249 has a cross-section larger
than that of the body portion 259. Additionally, the head portion
258 comprises a slot 261 centrally positioned on the second end 257
and an external (male) screw thread 262. The screw thread 262 is
adapted to be at least partially received by a portion of the
metatarsal articulation member 246, phalanx articulation member
247, or both. As shown, the slot 261 has a generally rectangular
cross-section. However, it is also contemplated that the slot 261
could alternatively have another suitable cross-section. The
locking member 249 is adapted to be received within the cavity 254
of the base member 248. When the locking member 249 is so received,
the head portion 258 abuts the second end 251 of the base member
248. It is also contemplated that the head portion 258 could be
spaced from the second end 251 when so received. The combination of
the locking member 249 and base member 248 is adapted be at least
partially received by the metatarsal articulation member 246, the
phalanx articulation member 247, or both.
[0143] As further illustrated in FIG. 25, the metatarsal
articulation member 246 comprises a substantially convex bearing
surface 263 and a proximal surface 264 opposite thereto. As shown,
the proximal surface 264 is generally planar, but it is also
contemplated that it could be non-planar. The bearing surface 263
is adapted to emulate the general shape and function of the head
portion of the metatarsal bone within a metatarsophalangeal joint.
The metatarsal articulation member 246 also comprises a cavity 265
depressed from the center (not labeled) of the proximal surface
264. The cavity 265 comprises an interior (female) screw thread 266
adapted to receive at least a portion of the external screw thread
262 of the head portion 258 of the locking member 249. In some
embodiments, all of the head portion 258 may be received within the
cavity 265. The cavity 265 has a cross-section that matches that of
the head portion 258 of the locking member 249. As shown, the
cavity 265 has a circular cross-section.
[0144] As additionally illustrated in FIG. 25, the phalanx
articulation member 247 comprises a substantially concave bearing
surface 267 and a distal surface 268 opposite thereto. As shown,
the distal surface 268 is generally planar, but it is also
contemplated that it could be non-planar. The bearing surface 267
is adapted to emulate the general shape and function of the
proximal portion of the proximal phalanx bone within a
metatarsophalangeal joint. The phalanx articulation member 247 also
comprises a cavity 269 depressed from the center (not labeled) of
the distal surface 268. The cavity 269 comprises an interior
(female) screw thread 270 adapted to receive at least a portion of
the external screw thread 262 of the head portion 258 of the
locking member 249. In some embodiments, all of the head portion
258 may be received within the cavity 269. The cavity 269 has a
cross-section that matches that of the head portion 258 of the
locking member 249. As shown, the cavity 269 has a circular
cross-section.
[0145] In some embodiments of assembly, at least the first end 250
and body portion 253 of the base member 248 are first implanted
within the resected portion of the bone. Then the first end 256 of
the locking member 249 is inserted in and, using a tool that fits
the slot 261 of the locking member 249, screwed through the second
end 251 and head portion 252 of the base member 248, thereby
causing the body portion 253 of the base member 248 to expand with
sufficient force to fix the base member 248 and locking member 249
within the bone cavity. When so fixed, the head portion 258 of the
locking member 249 abuts or is proximate to the second end 251 of
the base member 248. Next, either the metatarsal articulation
member 246 or the phalanx articulation member 247 is placed over
the head portion 258 of the locking member 249 such that the head
portion 258 may be received within the cavity 265 or 269 of the
chosen articulation member 246 or 247. Finally, the chosen
articulation member 246 or 247 is screwed onto the head portion 258
of the locking member 249 to mechanically join the articulation
member chosen 246 or 247 with the base member 248.
[0146] Referring to FIGS. 26-27, illustrated is an example of an
implantable device of the invention which is designed to replace
all or a portion of a metatarsophalangeal joint. Such device
comprises one or more of: (i) a metatarsal component for surgical
implantation into the distal end of a metatarsal bone, comprising a
metatarsal articulation member comprising a substantially convex
bearing surface; and a locking member comprising a screw thread
adapted to fix the metatarsal component in the metatarsal bone; and
(ii) a phalanx component for surgical implantation into the
proximal end of a proximal phalanx bone, comprising a phalanx
articulation member comprising a substantially concave bearing
surface; and a locking member comprising a screw thread adapted to
fix the phalanx component in the phalanx bone.
[0147] In those embodiments wherein one of the components is
implanted, the chosen component is adapted to cooperatively engage
with and move with respect to either the proximal end of the
proximal phalanx bone or the distal end of the metatarsal bone. In
those embodiments wherein both of the components are implanted, the
metatarsal component and the phalanx component are adapted to
cooperatively engage such that the metatarsal articulation member
and the phalanx articulation member move with respect to each other
and collectively serve as a prosthetic metatarsophalangeal
joint.
[0148] As illustrated in FIG. 26, the two-component device 271
comprises a metatarsal component 272 designed to be implanted into
the distal end of a resected metatarsal bone, and a phalanx
component 273 designed to be implanted into the proximal end of a
resected proximal phalanx bone. The metatarsal component 272 may be
of any suitable length and dimension to allow for fixation within
the metatarsal bone, and may be fixed by any medically suitable
means. In some embodiments, the metatarsal component 272 is
designed to be implanted in approximately one third of the length
of the metatarsal bone. The phalanx component 273 may be of any
suitable length and dimension to allow for fixation within the
phalanx bone, and may be fixed by any medically suitable means. In
some embodiments, the phalanx component 273 is designed to be
implanted in approximately half of the length of the phalanx
bone.
[0149] In some embodiments, the components 272, 273 may be
implanted into one or both of the metatarsal and phalanx bones in a
primary resectional arthroplasty procedure, in a revision
arthroplasty procedure performed to replace or compensate for a
failed implant, or combinations thereof. In some embodiments,
implantation is by a primary arthroplasty procedure. In some
embodiments, each device implanted may be selected from small,
medium, or large sizes as necessary to approximate the anatomy of
the subject. In some embodiments, the components 272, 273 may
comprise one or more dimensions set forth in Table 8. In some
embodiments, each device and elements thereof may be customized to
the anatomy of the subject.
TABLE-US-00008 TABLE 8 Dimension Metatarsal and Phalanx (mm) Total
Length Metatarsal 22-26 Total Length Phalange 18-22 Locking Member
Length Metatarsal 22-26 Locking Member Length Phalange 18-22
Locking Member Head Height 2 Screw Head Diameter 10-13 Articulation
Member Height 10 (Excluding Bearing Surface) Phalanx Bearing
Surface Depth 3 Metatarsal Bearing Surface Height 3
[0150] As further illustrated in FIG. 27, the metatarsal component
272 comprises a first end 274, a second end 275 comprising a
metatarsal articulation member 276, and a locking member 277
comprising an external (male) screw thread 278. The screw thread
278 is adapted to be at least partially received within, and fix
the metatarsal component 272 to, a resected distal end of a
metatarsal bone. The locking member 277 is generally cylindrical
and has a generally circular cross-section. However, it is also
contemplated that the locking member 277 could alternatively be
non-cylindrical, have an different cross-section, or combinations
thereof. For example, a locking member 277 could be tapered or
conical or have a helical cross-section. The articulation member
276 of the metatarsal component 272 has a cross-section larger than
that of the locking member 277. Additionally, the metatarsal
articulation member 276 comprises a substantially convex bearing
surface 279. The bearing surface 279 is adapted to emulate the
general shape and, when implanted into the resected metatarsal
bone, function of the head portion of the metatarsal bone within a
metatarsophalangeal joint.
[0151] As additionally illustrated in FIG. 27, the phalanx
component 273 comprises a first end 280, a second end 281
comprising a phalanx articulation member 282, and a locking member
283 comprising an external (male) screw thread 284. The screw
thread 284 is adapted to be at least partially received within, and
fix the phalanx component 273 to, a resected proximal end of a
proximal phalanx bone. The locking member 283 is generally
cylindrical and has a generally circular cross-section. However, it
is also contemplated that the locking member 283 could
alternatively be non-cylindrical, have an different cross-section,
or combinations thereof. For example, a locking member 283 could be
tapered or conical or have a helical cross-section. The
articulation member 282 of the phalanx component 273 has a
cross-section larger than that of the locking member 283.
Additionally, the phalanx articulation member 282 comprises a
substantially concave bearing surface 285. The bearing surface 285
is adapted to emulate the general shape and, when implanted into
the resected proximal phalanx bone, function of the proximal
portion of the proximal phalanx bone within a metatarsophalangeal
joint.
[0152] In some embodiments of operation, at least the first end 274
and locking member 277 of the metatarsal component 272 are inserted
in and screwed into the distal end of a resected metatarsal bone.
In some embodiments, at least all of the locking member 277 is
screwed into the metatarsal bone. In some embodiments, all of the
locking member 277 and at least a portion of the metatarsal
articulation member 276 are implanted into the metatarsal bone. In
some embodiments, a portion ("screw head") of the metatarsal
articulation member 276 proximate to the locking member 277 may be
received within the resected bone. In some embodiments of
operation, at least the first end 280 and locking member 283 of the
phalanx component 273 are inserted in and screwed into the proximal
end of a resected proximal phalanx bone. In some embodiments, at
least all of the locking member 283 is screwed into the proximal
phalanx bone. In some embodiments, all of the locking member 283
and at least a portion of the phalanx articulation member 282 are
implanted into the proximal phalanx bone. In some embodiments, a
portion ("screw head") of the phalanx articulation member 282
proximate to the locking member 283 may be received within the
resected bone.
[0153] Referring to FIGS. 28-30, illustrated is an example of an
implantable device of the invention which is designed to replace
all or a portion of a metatarsophalangeal joint. Such device
comprises one or more of: (i) a metatarsal component for surgical
implantation into the distal end of a metatarsal bone, comprising a
metatarsal articulation member comprising a substantially convex
parabolic bearing surface terminating at equidistantly positioned
ends; and (ii) a phalanx component for surgical implantation into
the proximal end of a proximal phalanx bone, comprising a phalanx
articulation member comprising a substantially concave bearing
surface.
[0154] In those embodiments wherein one of the components is
implanted, the chosen component is adapted to cooperatively engage
with and move with respect to either the proximal end of the
proximal phalanx bone or the distal end of the metatarsal bone. In
those embodiments wherein both of the components are implanted, the
metatarsal component and the phalanx component are adapted to
cooperatively engage such that the metatarsal articulation member
and the phalanx articulation member move with respect to each other
and collectively serve as a prosthetic metatarsophalangeal
joint.
[0155] As illustrated, the two-component device 286 comprises a
metatarsal component 287 and a phalanx component 288. The
metatarsal component 287 is designed to be implanted into the
distal end of a resected metatarsal bone to replace all or a
portion of the metatarsal head and function as the metatarsal
component of the metatarsophalangeal joint. The phalanx component
288 is designed to be implanted into the proximal end of the
proximal phalanx and function as the phalanx component of the
metatarsophalangeal joint.
[0156] In some embodiments, the components 287, 288 may be
implanted into one or both of the metatarsal and phalanx bones in a
primary resectional arthroplasty procedure, in a revision
arthroplasty procedure performed to replace or compensate for a
failed implant, or combinations thereof. In some embodiments,
implantation is by a revision arthroplasty procedure. In some
embodiments, each device implanted may be selected from small,
medium, or large sizes as necessary to approximate the anatomy of
the subject. In some embodiments, the components 287, 288 may
comprise one or more of the dimensions set forth in Table 9. In
some embodiments, each device and elements thereof may be
customized to the anatomy of the subject.
TABLE-US-00009 TABLE 9 Dimension (mm) Metatarsal Stem Length 10-11
Stem Diameter 5-6 Articulation Member Width 18-19 Articulation
Member Diameter 12-14 Phalanx Stem Length 10-11 Stem Diameter 5-6
Articulation Member Height 16-18 Articulation Member Width 20-21
Articulation Member Diameter 12-14
[0157] In some embodiments, the material of composition of the
components 287, 288 is pyrocarbon. In some embodiments, the
material of composition is pyrocarbon having a coating to enhance
bone growth. In some embodiments, the coating is titanium plasma
spray.
[0158] As further illustrated in FIG. 29, the metatarsal component
287 comprises a metatarsal articulation member 289, a stem 290, and
a proximal end 291. The metatarsal articulation member 289
comprises a substantially convex bearing surface 292 having a
parabolic cross-section and a proximal surface 293 opposite
thereto. In some embodiments, the proximal surface 293 has a
semi-circular cross-section. However, alternative cross-sections
are also contemplated. For example, semi-elliptical, semi-oval, or
parabolic cross-sections. In some embodiments, the convex bearing
surface 292 and proximal surface 293 comprise shared ends 294 that
are equidistantly positioned with respect to each other. In some
embodiments, the ends 294 are equidistantly position with respect
to each other and the stem 290. The bearing surface 292 is adapted
to emulate the general shape and function as the head portion of
the metatarsal bone within a metatarsophalangeal joint.
[0159] The stem 290 protrudes from the center (not labeled) of the
proximal surface 293, terminates at the proximal end 291, and is
adapted to be received within a resected metatarsal bone. As shown,
the stem 290 is conical or tapered and has a circular
cross-section. In some embodiments, the stem 290 is tapered and has
a taper angle of from about 0-10.degree.. However, it is also
contemplated that the stem 290 could alternatively be non-conical
or non-tapered, have another suitable cross-section, or
combinations thereof. For example, a stem 290 could be cylindrical,
have a cross-section selected from generally elliptical, square,
triangular, or other suitable shape, or combinations thereof. The
stem 290 may be of any suitable length and dimension to allow for
fixation within the metatarsal bone, and may be fixed by any
medically suitable means. In some embodiments, the stem 290 is
designed to be implanted in approximately one third of the length
of the metatarsal bone. In some embodiments, it may be fixed with
bone cement.
[0160] In some embodiments of operation, the proximal end 291 and
at least a portion of the stem 290 of the metatarsal component 287
are implanted into the distal end of a resected metatarsal bone. In
some embodiments of operation, the proximal end 291 and the entire
stem 290 are implanted such that the proximal surface 293 abuts the
distal end of the resected metatarsal bone. In some embodiments,
the metatarsal component 287 is designed to be implanted without a
washer or other spacer means between the proximal surface 293 and
the bone.
[0161] As further illustrated in FIG. 30, the phalanx component 288
comprises a phalanx articulation member 295, a stem 296, and a
distal end 297. The phalanx articulation member 295 comprises a
substantially concave bearing surface 298 and a distal surface 299
opposite thereto. As shown, the distal surface 299 is generally
planar, but it is also contemplated that it could be non-planar.
Moreover, as shown, the phalanx articulation member 295 has a
generally elliptical cross-section. It is contemplated, however,
that it could have another suitable cross-section, provided that
the metatarsal component 287 is correspondingly adapted to enable
cooperative engagement. The bearing surface 298 is adapted to
emulate the general shape and function as the proximal portion of
the proximal phalanx bone within a metatarsophalangeal joint. The
stem 296 protrudes from the center (not labeled) of the distal
surface 299, terminates at the distal end 297, and is adapted to be
received within a resected proximal phalanx bone. As shown, the
stem 296 is conical or tapered and has a circular cross-section. In
some embodiments, the stem 296 is tapered and has a taper angle of
from about 0-10.degree.. However, it is also contemplated that the
stem 296 could alternatively be non-conical or non-tapered, have
another suitable cross-section, or combinations thereof. For
example, a stem 296 could be cylindrical, have a cross-section
selected from generally elliptical, square, triangular, or other
suitable shape, or combinations thereof. The stem 296 may be of any
suitable length and dimension to allow for fixation within the
phalanx bone, and may be fixed by any medically suitable means. In
some embodiments, the stem 296 is designed to be implanted in
approximately half of the length of the phalanx bone. In some
embodiments, it may be fixed with bone cement.
[0162] In some embodiments of operation, the distal end 297 and at
least a portion of the stem 296 of the phalanx component 288 are
implanted into the proximal end of a resected proximal phalanx
bone. In some embodiments of operation, the distal end 297 and the
entire stem 296 are implanted such that the distal surface 299
abuts the proximal end of the resected proximal phalanx bone. In
some embodiments, the phalanx component 288 is designed to be
implanted without a washer or other spacer means between the distal
surface 299 and the bone.
[0163] In various embodiments, provided are methods of treating
hallux valgus, comprising replacing all or a portion of a
metatarsophalangeal joint with implantable devices selected from:
(i) a metatarsal component for surgical implantation into the
distal end of a metatarsal bone, comprising a metatarsal
articulation member comprising a substantially convex bearing
surface; (ii) a phalanx component for surgical implantation into
the proximal end of a proximal phalanx bone, comprising a phalanx
articulation member comprising a substantially concave bearing
surface; or (iii) a metatarsal component for surgical implantation
into the distal end of a metatarsal bone, comprising a metatarsal
articulation member comprising a substantially convex bearing
surface; and a phalanx component for surgical implantation into the
proximal end of a proximal phalanx bone, comprising a phalanx
articulation member comprising a substantially concave bearing
surface. In some embodiments, the provided methods may be used to
correct one or more of the hallus valgus angle and the
intermetatarsal angle. In some embodiments, the provided methods
may be used to provide a subject with alignment and articulation of
the metatarsal and proximal phalanx bones in a manner consistent
with that of a natural metatarsophalangeal joint. In some
embodiments, the provided methods may be performed without complex
assembly, positioning, or other manipulation of the implant device
by the surgeon. In some embodiments, one or more of the devices
illustrated in FIGS. 2-30 and further described herein may be
utilized with the provided methods.
* * * * *