U.S. patent application number 11/975184 was filed with the patent office on 2009-04-23 for fibular stiffener and bony defect replacer.
This patent application is currently assigned to InBone Technologies, Inc.. Invention is credited to Mark A. Reiley.
Application Number | 20090105840 11/975184 |
Document ID | / |
Family ID | 40564284 |
Filed Date | 2009-04-23 |
United States Patent
Application |
20090105840 |
Kind Code |
A1 |
Reiley; Mark A. |
April 23, 2009 |
Fibular stiffener and bony defect replacer
Abstract
A fibular implant is provided. The implant includes a stem
anchored to the fibula and a joint-body. The stem is at least
partially covered with a bony-in-growth surface. The joint body
includes an articulating surface for articulating with the talus.
The articulating surface is polished to reduce friction in the
ankle joint.
Inventors: |
Reiley; Mark A.; (Piedmont,
CA) |
Correspondence
Address: |
DUANE MORRIS LLP - Philadelphia;IP DEPARTMENT
30 SOUTH 17TH STREET
PHILADELPHIA
PA
19103-4196
US
|
Assignee: |
InBone Technologies, Inc.
|
Family ID: |
40564284 |
Appl. No.: |
11/975184 |
Filed: |
October 18, 2007 |
Current U.S.
Class: |
623/21.18 ;
623/47 |
Current CPC
Class: |
A61F 2002/30616
20130101; A61F 2220/0033 20130101; A61F 2310/00017 20130101; A61F
2310/00131 20130101; A61F 2002/3085 20130101; A61F 2310/00029
20130101; A61F 2002/30604 20130101; A61F 2/4606 20130101; A61F
2/4202 20130101; A61F 2002/421 20130101; A61F 2310/00796 20130101;
A61F 2310/00023 20130101; A61F 2002/30332 20130101; A61F 2310/0097
20130101 |
Class at
Publication: |
623/21.18 ;
623/47 |
International
Class: |
A61F 2/42 20060101
A61F002/42; A61F 2/64 20060101 A61F002/64 |
Claims
1. A fibular prosthetic comprising: a stem sized and configured for
insertion into the fibula; and a joint body sized and configured
for articulating with the talus, at least a portion of the stem
including a surface permitting bony in-growth.
2. The prosthetic of claim 1 wherein the stem structure is of a
cylindrical configuration.
3. The prosthetic according to claim 1 wherein the stem is of a
conical configuration.
4. The prosthetic according to claim 1 wherein the stem comprises a
prosthetic material.
5. The prosthetic according to claim 1 wherein the stem comprises a
biologic material.
6. The prosthetic according to claim 1 wherein the stem is
threaded.
7. The prosthetic according to claim 1 wherein the joint body is
coupled to said stem.
8. The prosthetic according to claim 1 wherein the joint body is
integrally formed to said stem.
9. The prosthetic according to claim 1 wherein the joint body
comprises a prosthetic material.
10. The prosthetic according to claim 1 wherein the joint body
comprises a biologic material.
11. The prosthetic according to claim 1 wherein the lateral
malleolus replacement potion includes an articulating surface for
articulating with the talus.
12. The prosthetic according to claim 11 wherein the articulating
surface is polished.
13. The prosthetic according to claim 11 wherein the joint body
further includes a lateral surface for engaging the fibula.
14. The prosthetic according to claim 13 wherein at least a portion
of the lateral surface is adapted for bony-in-growth.
15. The prosthetic according to claim 14 wherein the articulating
surface is polished.
16. A method comprising providing a fibular prosthetic, said
fibular prosthetic having a stem and a joint body coupled to said
stem; forming a cavity in the fibula, said cavity being sized and
configured for receiving the stem, and inserting the prosthetic
stem into the cavity in the fibula.
17. The method according to claim 16 further comprising fixing the
prosthetic stem in the fibula.
18. The method according to claim 17 wherein the prosthetic stem is
fixed in the fibula with bone cement.
19. The method according to claim 17 wherein the prosthetic stem is
formed with external threads.
20. The method according to claim 19 wherein the prosthetic stem is
fixed in the fibula by screwing the stem into the cavity in the
fibula.
Description
FIELD OF THE INVENTION
[0001] The invention relates to fibular replacement prostheses,
systems, and associated surgical procedures.
BACKGROUND OF THE INVENTION
[0002] Many times after trauma, previous ankle surgery where a
portion or the entire distal fibula has been removed, or congenital
deformity, adequate fibula does not remain to perform a desired
operation such as a total ankle replacement, ankle ligament repair,
or fibular osteotomy correction. Although the fibula does not carry
much of the weight in the leg, the distal fibula is required to
provide stability to the ankle joint. In these cases it would be
useful to have a device which both strengthens the fibula and
allows ample support of a replacement piece of the distal fibula,
also known as the lateral malleolus.
SUMMARY OF THE INVENTION
[0003] The present invention provides devices and methods for
stiffening the fibula and replacing a broken lateral malleolus.
[0004] The present invention may include an elongate stem for
inserting into the fibula and a joint body coupled to the stem
member for replacing the lateral malleolus.
[0005] The stem may take on various shapes and have various cross
sections.
[0006] Other objects, advantages, and embodiments of the invention
are set forth in part in the description which follows, and in
part, will be obvious from this description, or may be learned from
the practice of the invention.
BRIEF DESCRIPTION OF THE DRAWINGS
[0007] FIG. 1A is an anterior view of a human leg and showing the
leg and foot skeleton.
[0008] FIG. 1B is a lateral view of a human ankle joint showing the
ligaments.
[0009] FIG. 1C is a medial view of a human ankle joint showing the
ligaments.
[0010] FIG. 2 is an anterior view of the lower leg showing a
fractured lateral malleolus where the entire lateral malleolus is
broken off.
[0011] FIG. 3 is an anterior view of the lower leg showing a
fractured lateral malleolus where only a portion of the lateral
malleolus is broken off.
[0012] FIG. 4A is an anterior view of a lateral malleolus
prosthesis according to the presenting invention.
[0013] FIG. 4B is an alternate embodiment of the lateral malleolus
prosthesis of FIG. 4A.
[0014] FIG. 5 is an anterior view of the prosthesis of FIG. 4A
implanted in the lower leg of FIG. 2.
[0015] FIGS. 6A to 6D show the steps of the insertion of the
prosthesis of FIG. 4A into the lower leg of FIG. 2.
[0016] FIGS. 7A to 7E show the steps of the insertion of the
prosthesis of FIG. 4B into the lower leg of FIG. 2.
[0017] FIG. 8 is an anterior view of an alternate embodiment of a
lateral malleolus prosthesis.
[0018] FIG. 9 is a side view showing examples of the various
interchangeable components of the lateral malleolus prosthesis of
the present invention.
[0019] FIG. 10A is an anterior view of an additional alternate
embodiment of a lateral malleolus prosthesis.
[0020] FIG. 10B is an alternate embodiment of the lateral malleolus
prosthesis of FIG. 10A.
[0021] FIG. 11 is an anterior view the prosthesis of FIG. 10A
implanted in the lower leg of FIG. 3.
[0022] FIGS. 12A to 12D show the steps of the insertion of the
prosthesis of FIG. 10A implanted in the lower leg of FIG. 3.
DESCRIPTION OF THE PREFERRED EMBODIMENT
[0023] Although the disclosure hereof is detailed and exact to
enable those skilled in the art to practice the invention, the
physical embodiments herein disclosed merely exemplify the
invention which may be embodied in other specific structures. While
the preferred embodiment has been described, the details may be
changed without departing from the invention, which is defined by
the claims.
I. Anatomy of the Lower Leg
[0024] Referring to FIG. 1A, the lower leg comprises the tibia and
the fibula. The tibia and the fibula, along with the talus form the
ankle joint which allows for the up and down movement of the foot.
The subtalar joint, located below the ankle is made of the talus
and calcaneous. The subtalar joint allows for side to side movement
of the foot.
[0025] The distal end of the fibula enlarges to form the lateral
malleolus (see FIG. 1A). The distal end of the tibia forms the
medial malleolus. The medial malleolus and the lateral malleolus
each articulate with the lateral surface of the talus, as FIG. 1A
shows. The lateral malleolus of is an important element of the
ankle, as it lends stability to the ankle joint. Therefore, it is
desirable to replace a damaged lateral malleolus in order to create
a stable articulating ankle joint.
[0026] FIG. 1B shows the ligaments on the lateral side of the ankle
joint. The major ligaments on the lateral side are the anterior
talofibular ligament which connects the fibula to the talus, the
anterior tibiofibular ligament which connects the tibia to the
fibula and the calcaneofibular ligament which connects the fibular
to the calcaneous. These ligaments provide lateral stability to the
ankle.
[0027] FIG. 1C shows the ligaments on the medial side of the ankle
joint. The major ligament on the medial side is the medial deltoid
ligament which attaches proximally to the medial malleolus and fans
out to attach to the talus, calcaneous, and navicular bone. The
deltoid muscles provide medial stability to the ankle.
II. Fibular Prosthesis
[0028] FIGS. 2 and 3 show examples of a damaged fibula. Fibular
fractures commonly occur 2-6 cm proximal to the distal end of the
lateral malleolus. The fibula may be damaged due to injury,
surgery, or a congenital defect. The fibula may be broken above the
lateral malleolus, as shown in FIG. 2, or a portion of the lateral
malleolus may be broken off, as shown in FIG. 3.
[0029] A. Total Prosthesis
[0030] FIG. 4A shows an example of a fibular prosthetic 10 for use
in a fracture as shown in FIG. 2, where the entire lateral
malleolus is missing. The prosthetic 10 includes a stem 12 and a
joint body 14 coupled to the stem 12. The stem 12 reinforces the
fibula while the joint body 14 replaces the lateral malleolus.
[0031] In one embodiment the stem 12 comprises an elongated body.
However, it should be understood that the prosthesis stem 12 can
take various forms. The stem 12 may be of any size or shape deemed
appropriate by the physician. The stem 12 is desirable selected by
the physician taking into account the morphology and geometry of
the site to be treated. It should be understood that the stem 12
could be of virtually any width or length, depending upon the size
of the patient and his or her bone dimensions. While the stem 12 in
the disclosed embodiments has a circular cross-section, it should
be understood that the stem 12 could be formed in various other
cross-sectional geometries, including, but not limited to,
elliptical, polygonal, irregular, or some combination thereof.
[0032] The stem 12 may be made of any total joint material or
materials commonly used in the prosthetic arts, including, but not
limited to metals, ceramics, titanium, titanium alloys, tantalum,
chrome cobalt, surgical steel, or any other total joint replacement
metal and/or ceramic, bony in-growth surface, sintered glass,
artificial bone, any uncemented metal or ceramic surface, or a
combination thereof.
[0033] It may be desirable to provide surface texturing 13 along at
least a portion of the length of the stem 12 to promote bony
in-growth on its surface (see FIG. 4A). The surface texturing 13
can comprise, e.g., through holes, and/or various surface patterns,
and/or various surface textures, and/or pores, or combinations
thereof. The stem 12 can be coated or wrapped or surfaced treated
to provide the surface texturing 13, or it can be formed from a
material that itself inherently possesses a surface conducing to
bony in-growth, such as a porous mesh, hydroxyapetite, or other
porous surface.
[0034] If desired, the stem 12 may further be covered with one or
more coating 15 such as antimicrobial, antithrombotic, and
osteoinductive agents, or a combination thereof (see FIG. 4A). Any
of these coatings 15 may be used in conjunction with surface
texturing, if desired. Alternatively, the stem 12 may be formed
from a suitable biological material, or a combination of metal and
biological material, including, but not limited to hydroxyapetate,
calcium phosphate, or other biocompatible bony substitutes. The
stem 12 could further be covered with biological bone-growth
stimulants, e.g., but not limited to bone morphogenic proteins.
[0035] The stem 12 may be fixed in the fibula using
poly(methylmethacrylate) bone cement, hydroxyapatite, a ground bone
composition, screws, or a combination thereof, or any other
fixation materials or methods common to one of skill in the art of
prosthetic surgery, as is shown in FIGS. 6A to 6D.
[0036] Especially in cases of trauma, where the fracture of the
fibula is jagged as shown in FIG. 2, it may be desirable to create
a flat surface, such as that shown in FIG. 6A, for prosthetic
attachment. A flat surface can be created by using standard
surgical tools, such as a surgical saw to cut away a portion of the
fibula.
[0037] The physician may then use conventional methods to create a
bore of the desired size and configuration in the fibula, as shown
in FIG. 6B. Preferably, the physician will use a surgical drill
sized and configured to create a conical bore similar in size and
configuration to the stem 12. The bore is desirable sized and
configured to permit tight engagement of the stem 12 within the
bore and thereby restrict movement of the stem 12 within the bore.
As shown in FIG. 6C, the stem 12 is then inserted into the bore.
The pre-formed bore may be slightly smaller than the stem 12, while
still allowing the stem 12 to be secured into position within the
bore by tapping.
[0038] As shown in FIG. 6D, the illustrated embodiment of the joint
body 14 has generally the same configuration as a human lateral
malleolus. The joint body 14 includes an articulating surface 18
that articulates with the talus to form the ankle joint. The
articulating surface 18 of the joint body 14 is preferably made of
a polished biocompatible metal or metallic alloy that allows as
frictionless an engagement with the talus as possible.
[0039] In an alternate embodiment of the fibular stiffener 210 the
stem 212 is formed with external screw-like threads 224 along the
stem 212 (see FIG. 4B). In this arrangement, the threaded stem 212
can be screwed into a pre-drilled bore in the fibula, as shown in
FIGS. 7A to 7E. In inserting the threaded stem, it may be desirable
to have the stem and the joint body formed as two separate parts,
as will be described in detail below.
[0040] As shown in FIG. 2, the fracture may leave a jagged surface
on the lateral malleolus. The physician may first use standard
surgical tools, such as a bone saw to create a flat surface, such
as that shown in FIG. 7A, for prosthetic attachment. The physician
may then use a tool such as a surgical drill to create a bore sized
and configured to engage the stem 212, as shown in FIG. 7B. As
shown in FIG. 7C, The physician may then screw the stem 212 into
the preformed bore. A suitable tool 26 may be used to aid in
insertion of the stem. Preferably, the diameter of the bore is
slightly smaller than diameter of the stem 212 so that the threads
224 on the stem 212 may engage the fibula. The joint body 14 is
then attached to the stem 212, as shown in FIG. 7D.
[0041] As shown in FIG. 7E, the illustrated embodiment of the joint
body 14 has generally the same configuration as a human lateral
malleolus. The joint body 14 includes an articulating surface 18
that articulates with the talus to form the ankle joint. The
articulating surface 18 of the joint body 14 is preferably made of
a polished biocompatible metal or metallic alloy that allows as
frictionless an engagement with the talus as possible.
[0042] In some cases it may be desirable to allow for ligament
attachment to the prosthesis. FIG. 8 shows an alternative joint
body 114 which may therefore further be formed with holes 20
therethrough. These holes 20 may be used to facilitate ligament
attachment. For example, sutures may be passed through the holes 20
and through the ligaments to attach the ligaments to the joint body
114. At least a portion of the joint body 114 may be covered with
biologic surfaces 21, as shown in FIG. 8 to enable ligament
reattachment.
[0043] As shown in FIG. 9, as described above, the stem 12 and
joint body 14 can be formed as a single unit, or as a
multi-component prosthesis. The distal end of the stem 12 may
having interlocking components, common to those of skill in the art
to allow other components of the prosthetic body to lock into the
stem 12. For example, as shown in FIG. 9, the end of the stem may
be formed with a Morse Taper. In this manner, the treating
physician may choose an appropriately sized and configured stem 12
or 212, and an appropriately sized and configured joint body 14,
114, or 214 based on the patent's anatomy and the particular
configuration of the damaged fibula.
[0044] B. Partial Prosthesis
[0045] FIG. 10A shows an example of a prosthetic 210 for use in a
fracture as shown in FIG. 3 where only a portion of the lateral
malleolus is missing. The prosthetic 210 includes a stem 12 as
described above and a partial joint body 214. The partial joint
body 214 is designed to have a portion that engages the fibula and
a portion that articulates with the talus to form the ankle
joint.
[0046] In the illustrated embodiment of FIG. 10A, the stem 12
comprises an elongated body. However, it should be understood that
the prosthesis stem 12 can take various forms. For example, as
shown in FIG. 10B, the stem 212 may be formed with external threads
along the body of the stem.
[0047] The stem 12 may be of any size or shape deemed appropriate
by the physician. The stem 12 is desirable selected by the
physician taking into account the morphology and geometry of the
site to be treated. It should be understood that the stem 12 could
be of virtually any length or width, depending upon the size of the
patient and his or her bone dimensions. While the stem 12 in the
disclosed embodiments has a generally circular cross-section, it
should be understood that the stem 12 could be formed in various
other cross-sectional geometries, including, but not limited to,
elliptical, polygonal, irregular, or some combination thereof.
[0048] The stem 12 may be made of any total joint material or
materials commonly used in the prosthetic arts, including, but not
limited to metals, ceramics, titanium, titanium alloys, tantalum,
chrome cobalt, surgical steel, or any other total joint replacement
metal and/or ceramic, bony in-growth surface, sintered glass,
artificial bone, any uncemented metal or ceramic surface, or a
combination thereof.
[0049] It may be desirable to provide surface texturing 13 along at
least a portion of the length of the stem 12 to promote bony
in-growth on its surface (see FIG. 10A). The surface texturing 13
can comprise, e.g., through holes, and/or various surface patterns,
and/or various surface textures, and/or pores, or combinations
thereof. The stem 12 can be coated or wrapped or surfaced treated
to provide the surface texturing 13, or it can be formed from a
material that itself inherently possesses a surface conducing to
bony in-growth, such as a porous mesh, hydroxyapetite, or other
porous surface.
[0050] If desired, the stem 12 may further be covered with one or
more coatings 15 such as antimicrobial, antithrombotic, and
osteoinductive agents, or a combination thereof (see FIG. 10A). Any
of these coatings 15 may be used in conjunction with surface
texturing, if desired. Alternatively, the stem 12 may be formed
from a suitable biological material, or a combination of metal and
biological material, including, but not limited to hydroxyapetate,
calcium phosphate, or other biocompatible bony substitutes. The
stem 12 could further be covered with biological bone-growth
stimulants, e.g., but not limited to bone morphogenic proteins.
[0051] The stem 12 may be fixed in the fibula using
poly(methylmethacrylate) bone cement, hydroxyapatite, a ground bone
composition, screws, or a combination thereof, or any other
fixation materials or methods common to one of skill in the art of
prosthetic surgery.
[0052] Especially in cases of trauma, where the fracture of the
fibula is jagged as shown in FIG. 3, it may be desirable to create
a flat surface, such as that shown in FIG. 12A for prosthetic
attachment. A flat surface can be created by using a surgical saw
to cut away a portion of the fibula.
[0053] The physician may then use conventional methods to create a
bore of the desired size and configuration in the fibula, as shown
in FIG. 12A. Preferably, the physician will use a surgical drill
sized and configured to create a conical bore similar in size and
configuration to the stem 12. The bore is desirable sized and
configured to permit tight engagement of the stem 12 within the
bore and thereby restrict movement of the stem 12 within the bore.
As shown in FIGS. 12B and 12C, the stem 12 of the prosthesis is
then inserted into the bore. The stem may be inserted by standard
surgical methods. For example, the stem could be inserted by
tapping the stem with a surgical tool such as a mallet. The
pre-formed bore may be slightly smaller than the stem 12, while
still allowing the stem 12 to be secured into position within the
bore by tapping. When inserted, the joint body 214 of the
prosthesis articulates with the talus, as shown in FIG. 12D.
[0054] In an additional alternate embodiment of a fibular stiffener
410 shown in FIG. 10B, the stem 212 is formed with external
screw-like threads 224 along the stem 212. In this arrangement, the
threaded stem 212 can be screwed into a pre-drilled bore in the
fibula, in the same manner as described above and shown in FIGS. 7A
to 7E. In inserting the threaded stem, it may be desirable to have
the stem and the joint body formed as two separate parts, as is
shown in FIG. 9, and will be described in detail below.
[0055] As shown in FIG. 3, the fracture may leave a jagged surface
on the lateral malleolus. The physician may first use standard
surgical tools, such as a bone saw to create a flat surface, such
as that shown in FIG. 12A, for prosthetic attachment. The physician
may then use a tool such as a surgical drill to create a bore sized
and configured to engage the stem 212, as shown in FIG. 12B. As
shown in FIG. 7C, the physician may then screw the stem 212 into
the preformed bore. A suitable tool 26 may be used to aid in
insertion of the stem. Preferably, the diameter of the bore is
slightly smaller than diameter of the stem 212 so that the threads
224 on the stem 212 may engage the fibula. The joint body 214 is
then attached to the stem, as shown in FIG. 12 D. The joint body
214 may then articulate with the talus as shown in FIG. 12D.
[0056] As shown in FIGS. 10A and 10B, the illustrated embodiment of
the joint body 214 has generally the same configuration as the
missing portion of a human lateral malleolus. The joint body 214
includes a portion 22 that engages the fibula, on the lateral side
of the partial joint body 214. The fibula engaging portion 22 may
desirably be formed with a bony-in-growth surface, such as through
holes, and/or various surface patterns, and/or various surface
textures, and/or pores, or combinations thereof. The fibula
engaging portion 22 can be coated or wrapped or surfaced treated to
provide the surface texturing, or it can be formed from a material
that itself inherently possesses a surface conducing to bony
in-growth, such as a porous mesh, hydroxyapetite, or other porous
surface. The fibula engaging portion 22 could further be covered
with biological bone-growth stimulants, e.g., but not limited to
bone morphogenic proteins.
[0057] As shown in FIG. 12D, the joint body 214 also includes an
articulating surface 18 for engaging the talus. It is desirable
that the articulating surface 18 of the partial joint body 214
should be made of a polished biocompatible metal or metallic allow
to reduce friction as the prosthesis 210 articulates with the
talus.
[0058] As shown in FIG. 9, as described above, the stem 12 and
joint body 214 may be formed as a single unit, or as a
multi-component prosthesis. The distal end of the stem 12 may
having interlocking components, common to those of skill in the art
to allow other components of the prosthetic body to lock into the
stem 12. For example, as shown in FIG. 9, the end of the stem may
be formed with a Morse Taper. In this manner, the treating
physician may choose an appropriately sized and configured stem 12
or 212, and an appropriately sized and configured joint body 14,
114, or 214 based on the patent's anatomy and the particular
configuration of the damaged fibula.
[0059] The foregoing is considered as illustrative only of the
principles of the invention. Furthermore, since numerous
modifications and changes will readily occur to those skilled in
the art, it is not desired to limit the invention to the exact
construction and operation shown and described. While the preferred
embodiment has been described, the details may be changed without
departing from the invention, which is defined by the claims.
* * * * *