U.S. patent application number 13/182901 was filed with the patent office on 2011-11-10 for method of preparing an ankle joint for replacement, joint prosthesis, and cutting alignment apparatus for use in performing an arthroplasty procedure.
Invention is credited to Carl T. HASSELMAN.
Application Number | 20110276052 13/182901 |
Document ID | / |
Family ID | 38288348 |
Filed Date | 2011-11-10 |
United States Patent
Application |
20110276052 |
Kind Code |
A1 |
HASSELMAN; Carl T. |
November 10, 2011 |
Method of Preparing an Ankle Joint for Replacement, Joint
Prosthesis, and Cutting Alignment Apparatus for Use in Performing
an Arthroplasty Procedure
Abstract
A method prepares an ankle joint of a patient for replacement.
The patient includes a tibia (20) having a medial portion (22), a
talus (40), and an ankle (10) having a medial portion. The method
employs a cutting alignment apparatus (50) including a first
portion external to the patient and a second portion, and
surgically prepares and exposes the medial portion of the ankle for
replacement. The second portion of the cutting alignment apparatus
is coupled to the tibia, and a cutting guide (90) is disposed with
respect to the cutting alignment apparatus. The medial portion of
the tibia is detached, a portion of the tibia proximate the talus
is cut, and a portion of the talus proximate the tibia is cut. An
ankle prosthesis (100) is installed to the ankle, and the medial
portion of the tibia is reattached.
Inventors: |
HASSELMAN; Carl T.;
(Oakmont, PA) |
Family ID: |
38288348 |
Appl. No.: |
13/182901 |
Filed: |
July 14, 2011 |
Related U.S. Patent Documents
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Application
Number |
Filing Date |
Patent Number |
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12161244 |
Jul 17, 2008 |
8002841 |
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PCT/US2007/060470 |
Jan 12, 2007 |
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13182901 |
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60761007 |
Jan 20, 2006 |
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60781634 |
Mar 13, 2006 |
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Current U.S.
Class: |
606/87 |
Current CPC
Class: |
A61F 2002/30232
20130101; A61F 2002/30649 20130101; A61F 2310/00029 20130101; A61F
2002/4205 20130101; A61F 2002/4207 20130101; A61F 2002/30891
20130101; A61F 2/4202 20130101; A61F 2230/0069 20130101; A61B 17/15
20130101; A61F 2002/30357 20130101; A61F 2220/0033 20130101 |
Class at
Publication: |
606/87 |
International
Class: |
A61B 17/00 20060101
A61B017/00 |
Claims
1-30. (canceled)
31. A cutting alignment apparatus for arthroplasty procedures,
comprising: a first positioning member extending along a first
longitudinal axis and including a first alignment element extending
laterally therefrom to determine a location of a tibia, the first
position member including an opening extending laterally
therethrough substantially parallel to the first alignment
extension to receive a bone fixation element configured to fix the
first positioning member to the tibia; and a cutting guide coupled
to the first positioning member such that when the first member is
fixed to the tibia, the cutting guide is positioned along a medial
portion of the tibia and a talus, the cutting guide including a
first cutting slot extending therethrough to guide a blade to
resect a desired portion of the tibia and a second cutting slot
extending therethrough to guide a cutting blade to resect a desired
portion of the tibia.
32. The apparatus according to claim 31, wherein the first
positioning member includes an alignment channel extending
longitudinally therethrough and a second alignment element sized
and shaped for insertion through the alignment aperture to
determine a desired alignment of the first positioning member with
the tibia.
33. The apparatus according to claim 31, wherein the first
positioning member includes first rods extending laterally
therefrom substantially perpendicularly of the first alignment
extension rod, the apparatus further comprising: a second
positioning member extending along a longitudinal axis and
including first openings extending therethrough to receive the
first rods therein such that the second positioning member is
movable relative to the first positioning member along the first
rods and the longitudinal axes of the first and second positioning
members are substantially parallel to one another, the second
positioning member including second rods extending laterally
therefrom such that the second rods are substantially perpendicular
to the first rods; a third positioning member extending along a
longitudinal axis and including second openings extending
therethrough to receive the second rods therein such that the third
positioning members movable relative to the second positioning
member along the second rods and the longitudinal axes of the
second and third positioning members are substantially parallel to
one another, the cutting guide coupled to the third positioning
member such that the cutting guide is longitudinally movable
relative to the third positioning member to position the cutting
guide along the medial portion of the tibia and talus.
34. The apparatus of claim 33, wherein the cutting guide is coupled
to the third positioning member such that the cutting guide is
rotatable relative to the third positioning member.
35. The apparatus of claim 33, further comprising a locking
mechanism to fix the cutting guide in a desired position relative
to the third positioning member.
36. The apparatus of claim 31, wherein the cutting guide includes a
first mounting aperture extending therethrough to guide a cutting
tool along a portion of the tibia corresponding to a first mounting
projection of a joint prosthesis and a second mounting aperture
extending therethrough to guide a cutting tool along a portion of
the talus corresponding to a second mounting projection of a joint
prosthesis.
37. The apparatus of claim 36, wherein the first mounting aperture
is open to the first cutting slot and the second mounting aperture
is open to the second cutting slot.
38. The apparatus of claim 31, wherein the cutting guide includes a
locking hole extending therethrough and configured to receive a
locking element therethrough to fix the cutting guide to the medial
portion of one of the tibia and the talus.
39. A method for preparing an ankle for ankle joint replacement,
comprising: positioning a first positioning member of a cutting
alignment apparatus along a tibia of a patient using a first
alignment element extending laterally therefrom, the first
positioning member extending substantially perpendicularly to a
longitudinal axis of the first positioning member; fixing the first
positioning member to the tibia by inserting a bone fixation
element through an opening extending transversely through the first
positioning member; exposing a medial portion of the tibia and a
talus to which a joint prosthesis is to be implanted; and coupling
a cutting guide to the first positioning member such that the
cutting guide extends along the medial portion of the tibia and the
talus.
40. The method of claim 39, wherein positioning the first member
along the tibia includes aligning the first positioning member
along the tibia using a second alignment element extending
longitudinally through the first positioning member.
41. The method of claim 39, wherein the cutting guide is coupled to
the first positioning member via second and third positioning
member connected to one another, the second positioning member
extending along a longitudinal axis and including first openings
extending therethrough to receive first rods extending from the
first positioning member therein such that longitudinal axes of the
first and second positioning members are substantially parallel to
one another, the third positioning member extending along a
longitudinal axis and including second openings extending
therethrough to receive the second rods extending from the second
positioning member therein such that longitudinal axes of the
second and third positioning members are substantially parallel to
one another, the third positioning member extending along a medial
portion of the tibia.
42. The method of claim 41, adjusting the cutting guide alignment
apparatus to the patient by moving the second positioning member
relative to the first positioning member along the second rods and
moving the third positioning member relative to the second
positioning member along the second rods,
43. The method of claim 39, further comprising adjusting the
cutting guide to a desired configuration relative to medial portion
tibia and the talus.
44. The method of claim 43, wherein adjusting the cutting guide
includes rotating the cutting guide relative to the first
positioning member.
45. The method of claim 43, wherein adjusting the cutting guide
includes moving the cutting guide longitudinally relative to the
first positioning member.
46. The method of claim 43, further comprising locking the cutting
in the desired configuration.
47. The method of claim 39, further comprising resecting a desired
portion of the tibia and the talus using a blade inserted through
first and second cutting slots extending through the cutting
guide.
48. The method of claim 47, further comprising inserting a cutting
tool through a first mounting aperture extending through the
cutting guide to form a first recess in the tibia corresponding to
a first mounting projection of a joint prosthesis and through a
second mounting aperture extending through the cutting guide to
form a second recess corresponding to a second mounting projection
of a joint prosthesis.
49. The method of claim 48, sliding the first mounting projection
of the joint prosthesis through the first recess and sliding the
second mounting projection of the joint prosthesis through the
second recess to implant the joint prosthesis.
50. The method of claim 39, further comprising fixing the cutting
guide to the medial portion of one of the tibia and the talus by
inserting a locking element through a locking hole extending
through the cutting guide.
Description
CROSS-REFERENCE TO RELATED APPLICATIONS
[0001] This application claims the benefit of U.S. Provisional Pat.
Appl. Ser. No. 60/761,007, filed Jan. 20, 2006; and of U.S.
Provisional Pat. Appl. Ser. No. 60/781,634, filed Mar. 13,
2006.
BACKGROUND OF THE INVENTION
[0002] 1. Field of the Invention
[0003] This invention relates to a method of preparing an ankle
joint for replacement, and more particularly to an ankle prosthesis
and a method of preparing the ankle joint for replacement
implementing such ankle prosthesis and an alignment apparatus that
enables such replacement to be performed from a medial position on
the ankle.
[0004] 2. Background Information
[0005] Ankle prostheses and ankle replacement methods have been
implemented for the past few decades producing numerous prostheses
and approaches to the treatment of diseased, injured or otherwise
compromised ankle joints. Many types of total ankle prostheses have
been developed including a cylindrical-type ankle replacement, the
spherical-type ankle replacement, the sliding cylindrical-type
ankle replacement, the Buechel-Pappas Total Ankle Replacement
System, the Scandinavian Total Ankle Replacement system, or STAR
system, Hintegra ankle system, ESKA implant, and the Agility.TM.
Total Ankle System. Generally two broad categories exist in ankle
replacement prostheses, fixed-bearing ankle implants having fixed
components and mobile-bearing implants having mobile components.
The fixed-bearing ankle implants are generally semi-constrained,
although some are fully constrained, to have a single articulation
capability between a tibial and a talar component with some
allowance for rotation. The mobile-bearing implants have minimal
constraints due to the articulation permitted by a meniscus
positioned between tibial and talar components.
[0006] Many ankle prostheses in the United States are the
fixed-bearing ankle implant type, such as the Agility.TM. Total
Ankle System, due to its FDA approval status. In these types of
semi-constrained fixed bearing devices, the tibial prosthesis
component and the talar prosthesis component have a plastic insert
slidingly positioned within the tibial component between the two
components. In these fixed-bearing ankle implants, the two
components generally work directly with each other in various
fashions and all require incisions and installation from an
anterior position on the ankle, save certain methods published for
the ESKA ankle replacement.
[0007] Most of the known prostheses further require significant
amounts of bone to be resected from the tibia and talus in order to
install the traditionally bulky components into the ankle joint. As
is well known in the art, the more bone that is removed, or
resealed, the more likely the failure of the component as the bone
typically is its hardest at its outside surface. Thus, many devices
fail for reasons of subsidence of the component wherein the
significant bone resection and the implanting of a component will
cause the component to crush into the cancellous bone over time
under pressure.
[0008] Another ankle replacement that has been developed is the
ESKA implant which differs from the other ankle implants in that it
requires incision and installation from a lateral position on the
ankle. However, this preparation requires the devascularization of
the fibula, release of the syndesmotic ligaments and significant
bone resection.
[0009] No known prosthesis disclosed is designed, configured and
installed from a medial position on the ankle.
[0010] Some of the most common problems encountered with prior art
ankle prostheses are loosening of the components, instability, loss
of bone support, subsidence, inadequate motion and noticeable
scaring on the most visible parts of the ankle. Further, and more
importantly, ankle replacement is more challenging than other
procedures such as hip or knee replacement due to the limited soft
tissue envelope that is sparse at the ankle and has minimal
flexibility. Thus, ankle replacement is associated with a high
complication rate. This complication rate is exacerbated by the
dense intersection of tendons and nerves in the anterior (or front)
and lateral sides of the ankle.
[0011] Accordingly, wound problems are not uncommon due to the
present techniques and prostheses known in the art.
SUMMARY OF THE INVENTION
[0012] The present invention is directed to a method and apparatus
for ankle replacement. A cutting alignment apparatus may be
provided for assisting in performing an arthroplasty procedure. The
cutting alignment apparatus may include a first positioner having
first rods extending therefrom in a first direction and first
alignment extensions extending from the first positioner in a
second direction. The first positioner may further have securing
apertures extending through the first positioner in a second
direction. A second positioner may have second rods extending
therefrom in the second direction. The second positioner may
further have second apertures extending therethrough in the first
direction and may be in communication with the first positioner via
the first rods, which are positioned within the second apertures. A
third positioner may have third apertures extending therethrough in
the second direction wherein the third positioner is in
communication with the second positioner via the second rods
positioned within the third apertures. The third positioner may
further have a fourth aperture extending therethrough in a third
direction.
[0013] The method of ankle replacement may comprise the steps of
employing an external fixator apparatus to position an ankle,
surgically preparing and exposing a medial portion of the ankle for
replacement, forming at least one alignment aperture in a medial
portion of the tibia and performing an osteotomy of the medial
portion of the tibia, applying a cutting alignment apparatus such
that a cutting guide of the cutting alignment apparatus is
positioned in a desired orientation, cutting a portion of a tibia
and a talus of the ankle, installing an ankle prosthesis and
reattaching the medial portion of the tibia.
[0014] In accordance with one aspect of the invention, a joint
prosthesis comprises: a first joint component having a first
locking feature; a second joint component; and a meniscus insert
disposed between the first joint component and the second joint
component, wherein the meniscus insert has a second locking
feature, which is structured to lock to the first locking feature
of the first joint component, and wherein the first and second
locking features are both structured to permit the meniscus insert
to pivot with respect to the first joint component.
[0015] As another aspect of the invention, a method prepares an
ankle joint of a patient for replacement. The patient includes a
tibia having a medial portion, a talus, and an ankle having a
medial portion. The method comprises: employing a cutting alignment
apparatus including a first portion external to the patient and a
second portion; surgically preparing and exposing the medial
portion of the ankle for replacement; coupling the second portion
of the cutting alignment apparatus to the tibia; disposing a
cutting guide with respect to the cutting alignment apparatus;
detaching the medial portion of the tibia; cutting a portion of the
tibia proximate the talus; and cutting a portion of the talus
proximate the tibia.
[0016] As another aspect of the invention, a cutting alignment
apparatus is for use in performing an arthroplasty procedure of a
patient including a tibia having a medial portion, a talus, and an
ankle. The cutting alignment apparatus comprises: a first
positioner comprising first rods extending therefrom in a first
direction and first alignment extensions extending from the first
positioner in a second direction, the first positioner being
structured to be secured to the tibia; a second positioner
comprising second rods extending therefrom in the second direction,
and second apertures extending therethrough in the first direction,
the first rods of the first positioner being positioned within the
second apertures; a third positioner comprising third apertures
extending therethrough in the second direction, a fourth aperture
extending therethrough in a third direction, and a third rod
extending from the fourth aperture, the second rods of the second
positioner being positioned within the third apertures; and a
cutting guide positioned from the third rod and being structured to
face the medial portion of the tibia and the talus.
[0017] These and other features and characteristics of the present
invention, as well as the methods of operation and functions of the
related elements of structures and the combination of parts and
economies of manufacture, will become more apparent upon
consideration of the following description and the appended claims
with reference to the accompanying drawings, all of which form a
part of this specification, wherein like reference numerals
designate corresponding parts in the various figures. It is to be
expressly understood, however, that the drawings are for the
purpose of illustration and description only and are not intended
to unduly limit the present invention. As used in the specification
and the claims, the singular form of "a", "an" and "the" include
plural referents unless the context clearly dictates otherwise.
BRIEF DESCRIPTION OF THE DRAWINGS
[0018] FIG. 1 is a perspective view of an embodiment of a cutting
alignment apparatus in accordance with the present invention;
[0019] FIG. 2 shows a perspective view of an embodiment of a first
positioner in accordance with the present invention;
[0020] FIG. 3 is a perspective view of an embodiment of a second
positioner in accordance with the present invention;
[0021] FIG. 4 is a perspective view of an embodiment of a third
positioner having a cutting guide positioned thereon in accordance
with the present invention;
[0022] FIG. 5 shows a front elevational view of an embodiment of a
preparation step for the medial portion of the tibia in accordance
with the present invention;
[0023] FIG. 6 illustrates a lateral view of an ankle that has
undergone an embodiment of a preparation step for the medial
portion of the tibia in accordance with the present invention;
[0024] FIG. 6a illustrates a lateral view of an ankle that has
undergone an embodiment of a preparation step for the medial
portion of the tibia in accordance with the present invention;
[0025] FIG. 6b illustrates a lateral view of an ankle that has
undergone an embodiment of a preparation step for the medial
portion of the tibia in accordance with the present invention;
[0026] FIG. 7 is a lateral elevational view of an embodiment of a
first positioner, having an alignment rod positioned therethrough,
as it may be secured to the tibia in accordance with the present
invention;
[0027] FIG. 8 is a front elevational view of an embodiment of a
second and third positioner, having an alignment rod positioned
therethrough, as they may be positioned in accordance with the
present invention;
[0028] FIG. 9 shows a front elevational view of an embodiment of a
preparation step for the tibia and talus in accordance with the
present invention;
[0029] FIG. 10 is a perspective view of a saw as it may be used
with an embodiment of a cutting guide in accordance with the
present invention;
[0030] FIG. 11 is a front elevational view of an embodiment of a
preparation step for the tibia and the talus in accordance with the
present invention;
[0031] FIG. 12 is a plan view of an embodiment of a measuring
implement in accordance with the present invention;
[0032] FIG. 13 illustrates a front elevational view of an
embodiment of a preparation step utilizing the measuring implement
in accordance with the present invention;
[0033] FIG. 14 shows a perspective view of an embodiment of a
tibial component of an ankle replacement as it may be positioned in
accordance with the present invention;
[0034] FIG. 14a is a perspective view of an embodiment of a tibial
component of an ankle replacement in accordance with the present
invention;
[0035] FIG. 14b is a perspective view of an embodiment of a tibial
component of an ankle replacement in accordance with the present
invention;
[0036] FIG. 14c is a perspective view of an embodiment of a tibial
component of an ankle replacement in accordance with the present
invention;
[0037] FIG. 15 illustrates a perspective view of an embodiment of a
talar component of an ankle replacement as it may be positioned in
accordance with the present invention;
[0038] FIG. 16 is a perspective view of an embodiment of a meniscus
insert of an ankle replacement in accordance with the present
invention;
[0039] FIG. 16a is a perspective view of an embodiment of a
meniscus insert of an ankle replacement in accordance with the
present invention;
[0040] FIG. 16b is a perspective view of an embodiment of a
meniscus insert of an ankle replacement in accordance with the
present invention;
[0041] FIG. 17 is a front elevational view illustrating an
embodiment of an inserted ankle replacement and a preparation step
for the medial portion of the tibia in accordance with the present
invention;
[0042] FIG. 18 is a perspective view of an embodiment of a cutting
guide in accordance with the present invention;
[0043] FIG. 19 illustrates a perspective view of an embodiment of a
talar component of an ankle replacement as it may be positioned in
accordance with the present invention;
[0044] FIG. 20 is a perspective view of an embodiment of a cutting
guide in accordance with the present invention; and
[0045] FIG. 21 is illustrates a perspective view of an embodiment
of a talar component of an ankle replacement as it may be
positioned in accordance with the present invention.
DESCRIPTION OF THE PREFERRED EMBODIMENTS
[0046] For purposes of the description hereinafter, the terms
"upper", "lower", "right", "left", "vertical", "horizontal", "top",
"bottom", "lateral", "longitudinal" and derivatives thereof shall
relate to the invention as it may be oriented in the drawing
figures. However, it is to be understood that the invention may
assume various alternative variations and step sequences, except
where expressly specified to the contrary. It is also to be
understood that the specific devices and processes illustrated in
the attached drawings, and described in the following
specification, are simply exemplary embodiments of the invention.
Hence, specific dimensions and other physical characteristics
related to the embodiments disclosed herein are not to be
considered as unduly limiting. For example, certain portions of the
invention are shown as oblong blocks having circular holes
positioned therethrough, which could be configured in a number of
shapes and manners as various embodiments of the invention
described herein.
[0047] As employed herein, the term "osteotomy" is employed in
accordance with its traditional meaning to refer to the cutting or
otherwise suitable removal or severing of bone.
[0048] As employed herein, the terms "cut" and "cutting" refer to
the process of slicing, chiseling, or otherwise suitably removing
or severing bone.
[0049] As employed herein, the terms "drill" and "drilling" refer
to the process of creating a hole, bore or aperture in bone.
[0050] As employed herein, the term "cutting device" refers to any
known or suitable tool or mechanism suitable for "cutting"
bone.
[0051] As employed herein, the term "drilling device" or "drill"
refers to any known or suitable tool (e.g., without limitation,
drill bit) or mechanism for "drilling" bone.
[0052] As employed herein, the term "bone" refers to any known or
suitable human, animal or artificial structure suitable for use in
the body as a component of the skeleton.
[0053] As employed herein, the term "guide" refers to any known or
suitable mechanism, apparatus or fixture (e.g., without limitation,
jig), or suitable combination thereof, for establishing a
predetermined desired relationship (e.g., suitably precise
alignment) between two or more components in order to perform a
procedure (e.g., without limitation, an osteotomy) in a suitably
precise and accurate manner, which can be substantially replicated
or reproduced.
[0054] As employed herein, the terms "fastener" and "fastening
mechanism" refer to any known or suitable connecting, securing or
tightening material, structure or device and expressly include, but
are not limited to, suitable protrusions for securing one component
to another, as well as receptacles (e.g., without limitation,
recesses; slots; sockets; grooves), combinations of interlocking
protrusions and receptacles, welds, and devices such as pins,
rivets, screws, bolts and any suitable combination of bolts, nuts
(e.g., without limitation, lock nuts) and/or washers.
[0055] As employed herein, the statement that two or more parts are
"coupled" together shall mean that the parts are joined together
either directly or joined through one or more intermediate
parts.
[0056] As employed herein, the term "number" refers to the quantity
one or an integer greater than one (i.e., a plurality).
[0057] As employed herein, the term "patient" shall mean human
beings and other members of the animal kingdom.
[0058] As employed herein, the term "meniscus" shall mean any
mobile bearing structure or surface between two other structures or
surfaces, such as, for example, a meniscus insert between first and
second joint components.
[0059] The present invention is directed to an ankle prosthesis, a
method of preparing the ankle joint for replacement implementing
such ankle prosthesis and an alignment apparatus that enables such
replacement to be performed from a medial position on the ankle, as
illustrated in various embodiments in FIGS. 1-21. In general, an
ankle prosthesis 100 of the present invention is adapted for use in
connection with the method of preparing the ankle joint for
replacement, which may also implement a cutting alignment apparatus
50. As discussed hereinafter, the components of the ankle
prosthesis 100 and the cutting alignment apparatus 50 provide a
configurable and modifiable ankle replacement system and alignment
therefore, allowing a patient receiving such method of ankle
replacement to more effectively overcome the symptoms for which the
arthroplasty procedure was performed.
[0060] Generally in arthroplasty procedures, an external fixator
apparatus (not shown) may be applied to the area of interest to
assist in normalizing and distracting the joint that is intended to
undergo the medical procedure. More specifically, the external
fixator apparatus is employed to distract the bones concerned with
the ankle joints for positioning the ankle joint into proper
alignment. In a preferred embodiment, the method of preparing the
ankle joint includes applying the external fixator apparatus to the
lateral side of the lower leg of the patient.
[0061] As is common in the art of arthroplasty procedures, pins,
nails or screws may be placed into the tibia 20, the talus 40 and
the calcaneus 36. The external fixator apparatus may be actuated to
separate the tibia 20 from the talus 40 a sufficient distance such
that the proper alignment is achieved in order to perform the
remaining steps of the method of preparation of the present
invention. However, the final separation will be determined by the
medical professional implementing such external fixator apparatus
based upon the symptoms of the patient and the diagnosis of the
medical professional that will best accomplish a successful
arthroplasty procedure. After the arthroplasty procedure is
completed, the external fixator may be distracted slowly until the
ankle joint is in the proper alignment and pain is relieved. When
the medical professional is satisfied that distraction is no longer
necessary, the external fixator may be removed.
[0062] As can be seen in FIG. 5, the method of preparation includes
the forming of alignment apertures 21 into the medial portion 22 of
the tibia 20. The forming of the alignment apertures 21 may be
accomplished in a number of ways including, but not limited to,
drilling, boring, etc. with a tool 23. In a preferred embodiment,
at least two alignment apertures 21 may be formed in the medial
portion 22 of the tibia 20 as illustrated in FIG. 6. However, due
to varied circumstances it may only be necessary in certain
instances to form one alignment aperture 21 in an appropriate
location such as, for example, in the vicinity of the valley of the
chevron osteotomy discussed in greater detail below.
[0063] The method further includes an osteotomy of the medial
portion 22 of the tibia 20. In a preferred embodiment, the
osteotomy is performed forming tibial chevron section 25 where the
medial portion 22 of the tibia 20 is removed as shown in FIG. 6. In
order to perform such osteotomy, the posterior tibial tendon
retinaculum and superficial deltoid may be taken down such that the
medial portion 22 of the tibia 20 may be removed as illustrated in
FIGS. 6-6b.
[0064] Further, as can be seen in FIGS. 6a and 6b, more than one
type of osteotomy may be performed on the medial portion 22 of the
tibia 20 in accordance with the invention. For example, as shown in
FIG., 6a, a crescentic section 25a may be removed by using a
crescentic saw blade to perform the osteotomy. Similarly, as also
generally shown in FIG. 6a, a circular section 25a may be removed
by using a biradial saw blade. A further example of the osteotomy
that may be performed, as determined by the medical professional
implementing such method of preparation according to the present
invention, is a valley section 25b as illustrated in FIG. 6b.
Accordingly, any number of osteotomies may be performed, as may be
determined by the medical professional based upon the composure and
integrity of the medial portion 22 of the tibia 20 specific to the
patient undergoing such method of preparation may be used in
accordance with the present invention.
[0065] Next, a lateral incision (not shown) may be made over a
distal portion 32 of the fibula 30 which is shown in FIG. 8. The
incision may be made such that the syndesmosis located in this area
of the ankle may be exposed. A dissection may then be performed
such that at least the inferior aspect of the syndesmosis may be
taken down. This may further expose the distal portion 32 of the
fibula 30 to assist in performing the arthroplasty procedure and
preventing unnecessary damage to the distal portion 32 of the
fibula 30. For example, exposing this area visually enables
prevention of damage from over cutting, as will be described in
greater detail below, and may also provide access to the lateral
side of the ankle for assisting in positioning the ankle prosthesis
100 as can be seen in FIGS. 11, 13 and 17.
[0066] The cutting alignment apparatus 50, and components thereof,
is illustrated generally in FIGS. 1-4 and 7-11 for assisting in
performing an arthroplasty procedure as will be discussed in
greater detail below. The main components of the cutting alignment
apparatus 50 include a first positioner 60, a second positioner 70
and a third positioner 80. As can be seen in the drawings, a
cutting guide 90 may also be attached in order to perform
embodiments of the ankle preparation method described herein.
Although the cutting alignment apparatus 50 is separable for
convenience in sterilizing the cutting alignment apparatus 50, in
accordance with the present invention, the cutting alignment
apparatus 50 may also be unitary provided it allows for the same
functionality. Accordingly, when component portions of the cutting
alignment apparatus 50 are discussed, it is herein understood that
other portions of the cutting alignment apparatus 50 may also be
physically attached during these steps.
[0067] For purposes of describing the cutting alignment apparatus
50, several components of the cutting alignment apparatus 50 will
be described based upon their interspatial relations with other
components. Accordingly, a first direction 61, a second direction
71 and a third direction 81 will be used to describe these
interrelated components. As viewed in FIG. 1, the first direction
61 is indicated with an arrow and corresponds with the indicated
direction with reference to the X axis generally. Likewise, the
second direction 71 is also indicated with an arrow and corresponds
with the direction indicated by the arrow in reference to the Y
axis generally. The third direction 81 is also indicated with an
arrow and corresponds with the direction indicated with reference
to the Z axis generally. Again, these dimensional descriptions
related to the embodiments disclosed herein are not to be
considered as unduly limiting but are merely used for the purpose
of describing embodiments of the general interspatial relations of
the components of the present invention.
[0068] The first positioner 60 may be utilized for accomplishing
several attributes of alignment with regards to the expected
positioning of components that comprise the ankle joint. In
particular, referring to FIGS. 1, 2 and 7, the first positioner 60
may have an apparatus alignment rod 68 positioned within an
alignment rod aperture 67. The alignment rod aperture 67 may be
positioned through the first positioner 60 generally vertically or
in a direction with reference to the Z axis. Accordingly, the
alignment rod 68 may be retained within the alignment rod aperture
67 to assist in alignment of the ankle 10 with respect to various
alignment orientations such as, for example, varus/valgus
alignment.
[0069] Once alignment of the first positioner 60 is determined,
first alignment extensions 66 of the first positioner 60 may be
used to locate the tibia 20. First alignment extensions 66 extend
from the first positioner 60 in the second direction 71 generally.
The first positioner 60 may also have securing member apertures 65
extending through the first positioner 60 in the second direction
71 as well. The securing member apertures 65 preferably do not
intersect with the first alignment extensions 66, although it is
possible provided that alignment extensions 66 do not interfere
with elements positioned within securing member apertures 65 such
as, for example, where alignment extensions 66 are removable or
repositionable to prevent interference. Alternatively, securing
member apertures 65 may not be necessary and thus would not be
present in the first positioner 60, as will be discussed in greater
detail below.
[0070] While first alignment extensions 66 are resting on the tibia
20 with the first positioner 60 in the desired aligned orientation,
securing members 63 may be inserted into the tibia 20 through
securing member apertures 65 as illustrated in FIGS. 7 and 8.
Securing members 63 may generally comprise pins, nails or screws
that may be secured into the tibia 20, thus securing the first
positioner 60 in place. However, as mentioned above, securing
apertures 65 may not be necessary as alternative securing means
(not shown) may be implemented in place of securing members 63. For
example, a medical professional may determine to perform the method
of preparation implementing bone clamps (not shown) or securing
straps (not shown) to secure the first positioner 60 in place.
[0071] The first positioner 60 has first rods 64 extending from the
first positioner 60 in the first direction 61. The first rods 64
may be used to connect the first positioner 60 to the second
positioner 70, unless second positioner 70 is already connected in
a unitary embodiment. The first positioner 60, first rods 64 and
first alignment extensions 66 may be constructed of any suitable
materials able to undergo the sterilization processes required for
surgical instrumentation. Further, first rods 64 and first
alignment extensions 66 may or may not be detachable from the first
positioner 60 depending upon the desired orientation of the cutting
alignment apparatus 50 and restrictions of the required
sterilization processes and equipment.
[0072] The second positioner 70 has second rods 74 extending in the
second direction 71 from the second positioner 70. The second
positioner 70 also has second apertures 72 extending through the
second positioner 70 in the first direction 61. Thus, the first
rods 64 may be positioned within the second apertures 72 to connect
the second positioner 70 to the first positioner 60. The second
positioner 70 may then be in communication with the first
positioner 60 accordingly. In a preferred embodiment, the second
positioner 70 will be adjustably engaged with the first positioner
60 such that the second positioner 70 may be translated along first
rods 64 to be positioned appropriately for the overall alignment of
the cutting alignment apparatus 50. For example, the second
positioner 70 may slide along first rods 64 to allow adjustability.
The second rods 74 and second positioner 70 may likewise be
constructed of any suitable materials able to undergo the
sterilization processes required for surgical instrumentation and
may or may not be detachable from one another.
[0073] The third positioner 80 has third apertures 82 extending
through the third positioner 80 in the second direction 71. The
second rods 74 may be positioned within the third apertures 82.
Again, the positioning of the second rods 74 within the third
apertures 82 may form the connection between the second and third
positioners 70, 80 in the separable embodiment of the invention or
otherwise may already be thus positioned in the unitary embodiment.
Thus, the third positioner 80 may be in communication with the
second positioner 70 via the second rods 74 positioned within the
third apertures 82. In a preferred embodiment, the third positioner
80 may also be adjustably engaged with the second positioner 70 in
a similar manner as the connection between the first and second
positioners 60, 70 providing translation of the third positioner 80
in order to properly position the third positioner 80 for the
overall alignment of the cutting alignment apparatus 50.
[0074] The third positioner 80 also has a fourth aperture 86
extending through the third positioner 80 in the third direction
81. A third rod 84 may be positioned within the fourth aperture 86
that may be removable or merely adjustable within the fourth
aperture 86 as in the unitary embodiment. At the end of the third
rod 84, the cutting guide 90 may be positioned. Accordingly, the
cutting guide 90 may be in communication with the third positioner
80 such that the cutting guide 90 may be adjusted, or translated,
along at least the Z axis with reference to the third direction 81.
In order to assist in maintaining the desired position of the
cutting guide 90, at least one adjustor 85 may be employed.
Adjustor 85 may be a fine screw to allow for fine adjustments along
the Z axis or may otherwise be a course position holder used to
secure third rod 84 in a desired position. The cutting guide 90 may
also be permitted to rotate about the Z axis in order to permit
further adjustment if necessary.
[0075] The third positioner 80 may be utilized for accomplishing
several attributes of alignment with regards to the desired
positioning of the cutting guide 90 and the position of the lower
leg and ankle joint generally. In particular, referring to FIGS. 1,
4 and 8, the third positioner 80 may have a cutter alignment rod 88
positioned within a cutter alignment rod aperture 87. The cutter
alignment rod apciture 87 may be positioned through the third
positioner 80 generally vertically or in a direction with reference
to the Z axis. The cutter alignment rod 88 may thus be retained
within the cutter alignment rod aperture 87 to assess the alignment
of the ankle 10 and lower leg with respect to various alignment
orientations such as, for example, procurvation/recurvation
alignment. Once the alignment of the ankle 10 and lower leg is
diagnosed through the use of the cutter alignment rod 88, the
cutting guide 90 may be positioned more accurately to the desired
orientation.
[0076] The third positioner 80, third rod 84, cutter alignment rod
88, adjustor 85 and cutting guide 90 may all be constructed of any
suitable materials able to undergo the sterilization processes
required for surgical instrumentation and may or may not be
detachable from one another.
[0077] As shown in FIGS. 9-11, 14 and 15 in a preferred embodiment,
the cutting guide 90 is specifically configured to be implemented
with the particular mounting portions 112,122 of the ankle
prosthesis 100. Accordingly, the cutting guide 90 is provided with
mount cut apertures 91 that correspond with mounting portions
112,122 of the ankle prosthesis 100. Other mounting configurations
may require differing mount cut apertures depending upon the
configuration of alternate mounting portions in accordance with the
present invention. For example, alternate embodiments may include
triangular mounting portions 112b, cross mounting portions 112c,
etc. as opposed to cylindrical mounting portions 112,122 as will be
discussed in greater detail below.
[0078] As can be seen in FIGS. 1, 4 and 9-11, the cutting guide 90
has cutting slots 92 positioned therethrough. Cutting slots 92, in
the preferred embodiment, are of a sufficient length to permit
adequate cutting of the section of bone to be removed. In addition,
the cutting slots 92 have a sufficient height to permit a blade 142
of a saw 140 to pass therethrough while guiding the blade 142 along
the desired orientation of the cutting guide 90. Accordingly, the
cutting slots 92 are positioned to ensure the proper cut once the
cutting guide 90 is aligned.
[0079] Before the cutting step begins, the cutting guide 90 may be
secured to the tibia 20 to ensure the cutting guide 90 is properly
positioned. Thus, cutting guide 90 may be provided with cutting
securing member apertures 95 positioned therethrough. Accordingly,
cutting securing members 93 may affix the cutting guide 90 to the
ankle 10 to ensure a proper cutting location insertion into the
bone of the ankle 10. Securing members 93 may comprise nails,
screws, pins etc. Again, as with the first positioner 60, cutting
guide 90 may be secured to ensure proper cutting orientation in
other fashions in accordance with the present invention. For
example, a medical professional may determine to perform the method
of preparation implementing bone clamps (not shown) or securing
straps (not shown) to secure the cutting guide 90 in place.
[0080] The method may further include the use of retractors (not
shown) before the cutting step. Retractors are generally known in
the surgical arts and may be implemented to hold back the edges of
the surgical incision made on the medial area of the ankle 10.
[0081] As suggested above, protectors (not shown) may be inserted
into the area exposed near the distal portion 32 of the fibula 30
to prevent unnecessary damage that may occur from over cutting. In
addition, a stop 144 may be implemented on the blade 142 of the saw
140 to prevent over cutting.
[0082] Referring to FIGS. 9-11 and 13, the preparation of the tibia
20 and talus 40 of ankle 10 to receive the ankle prosthesis 100 is
shown. As can be seen in FIG. 9, a tool such as, for example, a
drill 97 may be used with the cutting guide 90 to form a tibial
mounting recess 26 in the tibia 20. The drill 97 is positioned
within the mount cut aperture 91 and inserted into the tibia 20 a
desired depth. Various methods to control the depth may be
implemented including, but not limited to, a stop (not shown) on
the drill, a mark on the drill 97 indicating the desired depth,
etc. As can be seen in FIG. 14, the tibial mounting recesses 26
will provide a configuration to which the ankle prosthesis 100 may
be secured. Likewise, the drill 97 may also be inserted into the
lower mount cut apertures 91 a desired depth to form a talar
mounting recess 44 in the talar dome 42 as shown in FIGS. 9 and
15.
[0083] As discussed above, alternate embodiments may include
triangular mounting portions 112b, cross mounting portion 112c,
etc., as opposed to cylindrical mounting portions 112,122 and
illustrated in FIGS. 14b-14c. Likewise, triangular mounting
portions and, cross mounting portions (similar to portions
112b,112c) may also be implemented in a similar fashion with other
mounting components of the ankle prosthesis 100 (i.e., talar
mounting component 120 discussed below). Accordingly, other tools
may be used to form mounting recesses that conform to the mounting
portions of the ankle prosthesis 100 selected by the medical
professional. In addition, the cutting guide will also be provided
with mount cut apertures that correspond with the desired shape of
mounting recesses in accordance with present invention.
[0084] With the cutting guide 90 secured to the ankle 10, and the
mounting recesses 26,44 formed, the osteotomy of the tibia 20 and
talar dome 42 may be performed using the saw 140 positioned through
the cutting slots 92. Although in the preferred embodiment the
mounting recesses 26,44 are formed before the osteotomy of the
tibia 20 and talar dome 42, these steps may be reversed as
preferred by the medical professional implementing such method of
preparation according to the present invention.
[0085] FIGS. 10 and 11 illustrate the saw blade 142 as it may be
utilized to make a generally straight cut to form tibial section 28
and a talar section 46. In the preferred embodiment, the tibial
section 28 will intersect the tibial mounting recess 26 and the
talar section 46 will intersect the talar mounting recess 44. Such
intersection will better prepare the ankle 10 to receive the ankle
prosthesis 100.
[0086] A measuring device 150 may be employed to determine the
appropriate size of the ankle prosthesis 100. As can be seen in
FIG. 13, the measuring device 150 is used to measure the dimensions
of the tibial section 28 as well as the talar section 46. The
measuring device 150 may be made of any suitable materials as are
consistent with the requirements of the sterilization processes
required. Further, the measuring device 150 may use any scale, as
indicated by the shading in FIG. 12, necessary to best correlate
that measurement with the appropriate sized ankle prosthesis
100.
[0087] As shown in FIGS. 14, 14a, 15, 16 and 17, the ankle
prosthesis 100 may include a tibial component 110, a talar
component 120 and a meniscus insert 130. When positioned together
in the preparation of an ankle replacement, they function to serve
the patient as an artificial ankle. The tibial component 110 is
impacted into tibial mounting recesses 26, as shown in FIG. 14,
using conventional methods known in the art. For example, as will
vary by medical professional and standards set by the FDA, the
tibial component insert 110 may be cemented into the tibia 20 or
otherwise secured as required by regulation. Likewise, as can be
seen in FIG. 15, the talar component 120 may be impacted into the
talar mounting recesses 44.
[0088] The tibial component 110 of the ankle prosthesis. 100 is
generally formed out of a plate 114 having the tibial mounting
portions 112 formed in the top of the plate 114. The plate 114 may
be treated or otherwise texturized to better assist in the
acceptance of the ankle prosthesis with the bone. On the opposing
side of the plate 114 from the tibial mounting portions 112 is
formed a recess 116 having inner walls 115 and a recessed surface
117. Recess 116 is provided to receive the meniscus insert 130
shown in FIG. 16. Within the recess 116 and extending toward the
tibial mounting portions 112 into the plate 114, is formed an
attachment recess 118 in the recessed surface 117. The tibial
component 110 may be made of suitable materials capable of
sterilization requirements and biomedical requirements for use with
resected bone material. Several alloy metal materials are
contemplated such as, for example, cobalt-chromium alloy, in the
preferred embodiment having a surface treatment to ensure their
smooth yet hard surface. However, any suitable material may be used
as required for the given application and factors taken into
consideration for the receiving patient.
[0089] The meniscus insert 130, as illustrated in FIG. 16, has an
attachment protrusion 138 that may take the form of a knob, a
sphere, a cone having its circular cross section position on a
post, etc. The attachment protrusion 138 in the preferred
embodiment includes a disk-like shape positioned on a post. The
meniscus insert 130 thus attaches to the tibial component 110 by
inserting the attachment protrusion 138 into the attachment recess
118 of the tibial component 110. Once attached, the meniscus insert
130 should not be able to be removed from the tibial component 110
in the preferred embodiment. Further, in many preparation methods
implemented according to the present invention, it may be
preferable to attach the meniscus insert 130 to the tibial
component 110 before impaction of the tibial component 110. In the
preferred embodiment, ultra-high molecular-weight polyethylene
(UHMWPE) may be used to form the meniscus insert 130 although other
suitable materials may be implemented.
[0090] Multiple shapes may be used to accomplish the securing of a
meniscus insert 130 to the tibial component 110 that are
contemplated within the scope of the present invention. For
example, as shown in FIG. 16a, the attachment protrusion 138a may
consist of a ridge that engages an attachment recess 118a of the
tibial component 110. See FIG. 14b. In this embodiment, the ridge
138a may fit within the attachment recess 118a to secure the
meniscus insert 130a to the tibial component 110. Further, in
certain installations, the meniscus insert may not require any
attachment protrusion as the compression of the weight upon the
ankle prosthesis 100 and the manner in which the installation is
performed by the medical professional may allow the ankle
prosthesis 100 assembly to hold the meniscus insert in place.
[0091] Additional embodiments include meniscus insert 130b having
lips 139a extending forward and rearward of a concave recess 139 of
meniscus insert 130b. Lips 139a are beneficial where sublexation,
or anterior/posterior migration, of the ankle prosthesis 100 may
occur. Thus, as the ankle joint may be thrust in a forward or
rearward direction parallel to the surface of the ground once
installed, lips 139a will assist the ankle prosthesis 100 from
slipping out of position, which would potentially cause the ankle
prosthesis 100 to become dislodged. However, it will be understood
that lips 139a will further be shaped so as to prevent unwanted
impingement of the user of the ankle prosthesis 100 while the ankle
joint is undergoing plantar flexion and/or dorsiflexion.
[0092] As can be seen in FIG. 15, the talar component 120 generally
forms a mound surface 129 having a generally convex shape. On the
underside of the mound 129 is formed talar mounting portions 122
projecting away from a flat surface 124. Further, the mound surface
129, flat surface 124 and talar mounting portions 122 are
intersected by sidewalls 125 of the talar component 120.
Preferably, talar component 120 is provided with a wide base that
approximates the shape of the talar section 46 of the talus 40 such
that subsidence of the talar component 120 will be minimized.
[0093] Further, other embodiments may provide additional beneficial
methods of preparation and talar components 120a,120b to further
prevent subsidence of the component wherein significant bone
resection and implanting of the component will not cause the
component to crush into the cancellous bone over time under
pressure. As can be seen in FIGS. 18-21, differing talar sections
46a,46b may be implemented in accordance with the present invention
for use with talar components 120a,120b having surfaces 124a,124b,
respectively. Likewise, matching cutting guides 90a,90b may be
implemented to assist in the shaping of talar sections 46a,46b,
respectively. More specifically, cutting slots 92a,92b having mount
cut apertures 91 on cutting guides 90a,90b will assist in the
shaping of the talar dome 42.
[0094] FIG. 17 illustrates ankle prosthesis 100 as it may be
permanently positioned and prepared. As can be seen in FIGS. 14-17,
the talar component 110 is attached to the meniscus insert 130 and
rests on the talar component 120. More specifically, an upper
surface 137 of the meniscus insert 130 interfaces with the recessed
surface 117 as the meniscus insert 130 rotates within the inner
walls 115. Further, the mound surface 129 of the talar component
120 interfaces with a concave recess 139 of the meniscus component
130. The interface between the talar component 120 and the meniscus
insert 130 is further partially constrained to a rocking motion by
the interface of recessed walls 135 of the meniscus insert 130 and
the sidewalls 125 of the talar component 120. Accordingly, the
interface between the tibial component 110 and the meniscus insert
130 permits the ankle prosthesis 100 limited rotational movement
while the interface of the talar component 120 and the meniscus
insert 130 provides limited front-to-back rocking motion for the
patient receiving the ankle prosthesis 100.
[0095] The final steps in the method of preparation according to
the present invention include replacing the medial portion 22 of
the tibia 20 with at least one screw 29. Thus, the tibial chevron
section 25 is resecured to the medial portion 22 of the tibia 20.
The incision is then closed after the posterior tibial tendon
retinaculum and superficial deltoid are repositioned or otherwise
treated, thus completing the method for preparing the ankle for
replacement according to the present invention.
[0096] Although the cutting alignment apparatus 50 may be employed
at any time before the cutting step in the method of preparation
described herein, it may be convenient to apply the cutting
alignment apparatus 50 just before the cutting step implementing
the cutting guide 90. However, other arrangements of the order of
steps are contemplated to accomplish the method of preparation of
the present invention. For example, it may be found convenient to
apply the cutting alignment apparatus 50 to achieve greater
confidence in alignment for certain medical professionals if
implemented earlier in the process immediately before the cutting
step implementing the cutting guide 90.
[0097] In addition, the present invention is applied from a medial
approach that endures to the benefit of the medical professional in
the ease of preparation of the ankle and the user of the ankle
replacement for healing purposes and overall stability of the ankle
joint after surgery. Further, because of the very common front to
back rocking motion of the ankle (plantar flexion/dorsiflexion),
the ability of the tibial and talar components to be mounted
transversely, i.e., with mounting portions transverse to the
motion/force applied to the ankle prosthesis, the ankle prosthesis
is thus provided with immediate rigid fixation and further
optimizes bony ingrowth of the ankle prosthesis.
[0098] Although the invention has been described in detail for the
purpose of illustration based on what is currently considered to be
the most practical and preferred embodiments, it is to be
understood that such detail is solely for that purpose and that the
invention is not limited to the disclosed embodiments, but, on the
contrary, is intended to cover modifications and equivalent
arrangements that are within the spirit and scope of the appended
claims. For example, it is to be understood that the present
invention contemplates that, to the extent possible, one or more
features of any embodiment can be combined with one or more
features of any other embodiment.
* * * * *