U.S. patent application number 12/337385 was filed with the patent office on 2009-11-19 for intra-articular joint replacement.
This patent application is currently assigned to TORNIER SAS. Invention is credited to Yves-Alain Ratron, Gilles Walch.
Application Number | 20090287309 12/337385 |
Document ID | / |
Family ID | 41316900 |
Filed Date | 2009-11-19 |
United States Patent
Application |
20090287309 |
Kind Code |
A1 |
Walch; Gilles ; et
al. |
November 19, 2009 |
INTRA-ARTICULAR JOINT REPLACEMENT
Abstract
A method for implanting an intra-articular shoulder prosthesis
is provided. The method includes removing a proximal portion of a
humerus. The proximal portion of the humerus preferably forms a
resected portion. The resected portion has a convex outer surface
and an inner surface. The method further includes engaging the
convex outer surface of the resected portion with a cut surface of
the proximal portion of the humerus. The cut surface of the
proximal portion of the humerus and/or the inner surface of the
resected portion are optionally processed to form a generally
concave surface, such as by impacting. In one embodiment, the inner
surface of the resected portion is impacted into engagement with
the cut surface of the proximal portion of the humerus. The
generally concave inner surface of the resected portion forms a
concave articular surface to receive an interpositional
implant.
Inventors: |
Walch; Gilles; (Lyon,
FR) ; Ratron; Yves-Alain; (Grenoble, FR) |
Correspondence
Address: |
FAEGRE & BENSON LLP;PATENT DOCKETING - INTELLECTUAL PROPERTY
2200 WELLS FARGO CENTER, 90 SOUTH SEVENTH STREET
MINNEAPOLIS
MN
55402-3901
US
|
Assignee: |
TORNIER SAS
Saint Ismier
FR
|
Family ID: |
41316900 |
Appl. No.: |
12/337385 |
Filed: |
December 17, 2008 |
Related U.S. Patent Documents
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Application
Number |
Filing Date |
Patent Number |
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12020913 |
Jan 28, 2008 |
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12337385 |
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60888437 |
Feb 6, 2007 |
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60971762 |
Sep 12, 2007 |
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61015042 |
Dec 19, 2007 |
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Current U.S.
Class: |
623/18.11 ;
606/87; 623/19.11 |
Current CPC
Class: |
A61L 27/18 20130101;
A61F 2310/00131 20130101; A61F 2/4014 20130101; A61F 2002/4233
20130101; A61B 17/842 20130101; A61B 17/8866 20130101; A61L 27/52
20130101; A61B 17/1682 20130101; A61F 2/28 20130101; A61B 17/0401
20130101; A61B 17/1686 20130101; A61B 17/86 20130101; A61F
2002/30754 20130101; A61F 2002/4085 20130101; A61L 27/042 20130101;
A61L 27/047 20130101; A61B 17/84 20130101; A61F 2002/30433
20130101; A61F 2002/3096 20130101; A61F 2310/00359 20130101; A61F
2002/30909 20130101; A61F 2310/00179 20130101; A61F 2002/30642
20130101; A61B 17/15 20130101; A61F 2002/4243 20130101; A61F
2220/0041 20130101; A61L 27/16 20130101; A61B 17/1684 20130101;
A61F 2002/4228 20130101; A61L 27/06 20130101; A61B 2017/00951
20130101; A61L 27/10 20130101; A61F 2/30 20130101; A61F 2002/30911
20130101; A61F 2310/00161 20130101; A61B 17/1739 20130101; A61F
2/4612 20130101; A61F 2002/4022 20130101; A61F 2/4059 20130101;
A61F 2310/00017 20130101; A61F 2002/4062 20130101; A61B 17/885
20130101; A61F 2/4081 20130101; A61F 2310/00023 20130101; A61F
2/4644 20130101; A61F 2002/4251 20130101; A61F 2/40 20130101 |
Class at
Publication: |
623/18.11 ;
606/87; 623/19.11 |
International
Class: |
A61F 2/30 20060101
A61F002/30; A61F 5/00 20060101 A61F005/00; A61F 2/40 20060101
A61F002/40 |
Foreign Application Data
Date |
Code |
Application Number |
Jan 30, 2007 |
FR |
0700622 |
Claims
1. A method of forming a prosthesis at the intersection of at least
two bones, the method comprising the steps of: removing a proximal
or distal portion of a bone to comprise a resected portion with an
outer convex surface and an inner surface; processing the inner
surface of the resected portion to comprise a concave articular
surface; implanting the outer convex surface of the resected
portion in a cut surface of the bone; and positioning an
interpositional implant in the concave articular surface.
2. The method of claim 1 comprising the steps of: positioning a
cutting template on the bone; and cutting the bone according to the
cutting template.
3. The method of claim 1 wherein the step of processing the inner
surface of the resected portion comprises compacting cancellous
bone.
4. The method of claim 1 wherein the step of processing the inner
surface of the resected portion comprises removing at least a
portion of cancellous bone in the resected portion.
5. The method of claim 1 comprising the step of implanting the
outer convex surface of the resected portion in the cut surface
before processing the inner surface of the resected portion.
6. The method of claim 1 wherein the resected portion comprises a
unitary structure.
7. The method of claim 1 comprising the step of compacting the cut
surface of the bone to form a recess with a shape generally
corresponding to the outer convex surface of the resected
portion.
8. The method of claim 1 comprising the step of reaming the cut
surface of the bone to form a recess with a shape generally
corresponding to the outer convex surface of the resected
portion.
9. The method of claim 1 comprising the steps of: locating the
outer convex surface of the resected portion on the cut surface of
the bone; and impacting the resected portion into the cut surface
of the bone.
10. The method of claim 1 wherein the step of implanting the
resected portion comprises the step of arranging a plurality of
pieces of the resected portion in the cut surface of the bone.
11. The method of claim 1 comprising attaching the resected portion
to the cut surface of the bone using one or more of fasteners, bone
anchors, or sutures.
12. The method of claim 1 comprising the step of locating a
reinforcing structure between the outer convex surface of the
resected portion and the cut surface of the bone.
13. The method of claim 1 comprising the steps of: positioning a
reinforcing structure across at least a portion of the cut surface
of the bone; and attaching the reinforcing structure to the
bone.
14. The method of claim 1 comprising selecting the interpositional
implant from one of a sphere or a disc.
15. The method of claim 1 comprising coating the interpositional
implant with pyrolytic carbon.
16. The method of claim 1 comprising drilling apertures in the cut
surface before implanting the resected portion.
17. The method of claim 1 wherein the bone comprises a proximal
portion of a humerus.
18. A method of forming a shoulder prosthesis, the method
comprising the steps of: removing a proximal portion of a humerus
to comprise a resected portion with an outer convex surface and an
inner surface; processing the inner surface of the resected portion
to comprise a concave articular surface; implanting the outer
convex surface of the resected portion in a cut surface of the
proximal portion of the humerus; and positioning an interpositional
implant in the concave articular surface.
19. The method of claim 18 comprising the steps of: positioning a
cutting template on the proximal portion of the humerus; and
cutting the proximal portion of the humerus according to the
cutting template.
20. The method of claim 18 wherein the step of implanting the
resected portion comprises the step of arranging a plurality of
pieces of the resected portion in the cut surface of the proximal
portion of the humerus.
21. The method of claim 18 comprising attaching the resected
portion to the cut surface of the proximal portion of the humerus
using one or more of fasteners, bone anchors, or sutures.
22. The method of claim 18 comprising the step of locating a
reinforcing structure between the outer convex surface of the
resected portion and the cut surface of the proximal portion of the
humerus.
23. The method of claim 18 comprising the steps of: positioning a
reinforcing structure across at least a portion of the cut surface
of the proximal portion of the humerus; and attaching the
reinforcing structure to the proximal portion of the humerus.
24. The method of claim 18 comprising the step of positioning a
support stem in a medullary cavity to support the resected
portion.
25. The method of claim 24 comprising the step of attaching the
resected portion to the support stem.
26. A method for replacing a joint between a first bone structure
and a second bone structure, the method comprising: resecting a
convex portion of the first bone structure to form a resected
portion having a convex surface, wherein the first bone structure
has a cut surface after resecting the convex portion; positioning
the convex surface of the resected portion against the cut surface
of the first bone structure; and driving the resected portion as a
single piece into the cut surface of the first bone structure to
form a concave articular surface.
27. The method of claim 26 comprising the step of processing the
cut surface of the first bone structure to form a recess with a
shape generally corresponding to the outer convex surface of the
resected portion.
28. The method of claim 26 comprising the steps of: locating the
outer convex surface of the resected portion on the cut surface of
the first bone structure; and impacting the resected portion into
the cut surface of the first bone structure.
29. The method of claim 26 comprising locating an interpositional
implant in the concave articular surface.
30. The method of claim 29 comprising coating the interpositional
implant with pyrolytic carbon.
31. The method of claim 26 comprising engaging a convex surface of
a glenosphere attached to the second bone structure with the
concave articular surface of the first bone structure.
32. The method of claim 26 wherein the first bone structure and the
second bone structure are located in one of a foot and a hand.
33. The method of claim 26 comprising replacing the joint by
engaging a convex surface on the second bone with the concave
articular surface.
34. The method of claim 26 comprising replacing the joint by
engaging a prosthetic element on the second bone with the concave
articular surface.
35. A shoulder prosthesis comprising: a resected portion of a
proximal portion of a humerus comprising an outer convex surface
engaged with a cut surface of the humerus and an inner surface
processed to comprise a concave articular surface; and an
interpositional implant positioned within the concave articular
surface.
36. The shoulder prosthesis of claim 35 wherein the inner surface
of the resected portion comprises compacting cancellous bone
against cortical bone comprising the outer convex surface.
37. The shoulder prosthesis of claim 35 wherein the inner surface
of the resected portion comprises cortical bone.
38. The shoulder prosthesis of claim 35 wherein the resected
portion comprises one of a unitary structure or a plurality of
pieces.
39. The shoulder prosthesis of claim 35 comprising one or more
fasteners, bone anchors, or sutures adapted to attach the resected
portion to a cut surface of the proximal portion of the
humerus.
40. The shoulder prosthesis of claim 35 comprising a reinforcing
structure located between the outer convex surface of the resected
portion and a cut surface of the proximal portion of the
humerus.
41. The shoulder prosthesis of claim 35 comprising a support stem
adapted for insertion into a medullary cavity to support the
resected portion.
42. The shoulder prosthesis of claim 35 comprising one or more
fasteners attaching the resected portion to the support stem.
43. The shoulder prosthesis of claim 35 wherein the interpositional
implant comprises one of a sphere or a disc.
44. The shoulder prosthesis of claim 35 wherein the interpositional
implant comprises pyrolytic carbon.
45. A prosthesis comprising: a resected portion of a bone structure
comprising an outer convex surface and an inner surface processed
to comprise a concave articular surface; and an interpositional
implant positioned within the concave articular surface.
46. The prosthesis of claim 45 wherein the interpositional implant
comprises one of a sphere or a disc.
47. The prosthesis of claim 45 wherein the interpositional implant
is located in one of a shoulder, a hip, an ankle, a foot, and a
hand.
48. A prosthesis joint between a first bone structure and a second
bone structure comprising: a resected portion of the first bone
structure comprising an outer convex surface engaged with a cut
surface of the first bone, and an inner surface of the resected
portion comprising a concave articular surface; and a convex
portion of the second bone engaged with the concave articular
surface comprising the prosthetic joint.
Description
CROSS REFERENCE TO RELATED APPLICATIONS
[0001] The present application is a continuation-in-part of U.S.
patent application Ser. No. 12/020,913 filed Jan. 28, 2008, which
claims priority to French application no. 0700622, entitled Methode
et ensemble d'instrumentation chirurgicale pour poser une prothese
totale d'epaule inversee, et prothese correspondante, filed Jan.
30, 2007, and also claims the benefit of U.S. Provisional
Application Ser. Nos. 60/888,437 filed Feb. 6, 2007 and 60/971,762
filed Sep. 12, 2007, both entitled Method And Apparatus For Fitting
An Inverted Shoulder Prosthesis, and U.S. Provisional Application
Ser. No. 61/015,042, entitled Intra-Articular Joint Replacement,
filed Dec. 19, 2007, the complete disclosures of which are hereby
incorporated by reference.
TECHNICAL FIELD
[0002] The present invention relates to a method and apparatus for
implanting a prosthesis at the intersection of two or more bone,
and in particular, to a method and apparatus for processing and
implanting a resected portion of a humerus to act as an articular
surface for an interpositional implant of a shoulder
prosthesis.
BACKGROUND OF THE INVENTION
[0003] In the field of total shoulder prostheses, prostheses are
commonly said to be inverted when they comprise a glenoid component
that is integral with the glenoid surface of a scapula of a
patient's shoulder and that delimits a convex articular surface and
a humeral component that is integral with the humerus of the
patient's shoulder and that delimits a concave articular surface.
The cooperation of the articular surfaces of the glenoid and
humeral components allow an articulated connection to be reproduced
at the shoulder. However, it is common with this type of prosthesis
that during adductive movement of the shoulder, the lower portion
of the humeral prosthetic component strikes the pillar of the
scapula, i.e. the lower portion of the glenoid located just below
the glenoid prosthetic component (when the patient is standing
upright). This interference between the humeral prosthetic
component and the scapula limits the range of adductive movement of
the shoulder and may cause pain to the patient or even lead to the
prosthesis becoming dislodged due to, for example, osteolysis of
the scapula.
[0004] Another method used to replace damaged shoulder joints is
interpositional arthroplasty. The method of interpositional
arthroplasty uses tissue from the patient or an artificial
replacement to repair a damaged or malformed joint. An
interpositional implant is positioned at the joint to act as an
engagement surface between two adjacent bone structures to allow
articular movement. In the particular field of interpositional
shoulder arthroplasty, the humeral metaphysis is typically impacted
to form an engagement surface for an interpositional implant
positioned between a glenoid component (or glenoid) and a humeral
component (or humeral metaphysis). However, if the cancellous bone
in the humeral metaphysis is of poor or degraded quality, the
cancellous bone may lead to gradual subsidence of the
interpositional implant within the humeral metaphysis. It is thus
desirable to develop an interpositional implant with a metaphyseal
articular surface that will provide support and protection to the
metaphyseal cancellous bone.
SUMMARY OF THE INVENTION
[0005] The present invention relates to a method and apparatus for
forming a prosthesis at the intersection of two or more bones. A
proximal or distal portion of a bone is removed, comprising a
resected portion with an outer convex surface and an inner surface.
The inner surface of the resected portion is processed, comprising
a concave articular surface. The outer convex surface of the
resected portion is implanted in a cut surface of the bone. In one
embodiment, an interpositional implant is positioned in the concave
articular surface that engages with the adjacent bone. In another
embodiment, a convex portion of an adjacent bone or another implant
is provided that engages with the concave articular surface. In
some embodiments, the ends of both bones forming the intersection
are processed as disclosed herein.
[0006] On embodiment of the present invention includes a method for
implanting a shoulder prosthesis. The method includes removing a
proximal portion of a humerus. The proximal portion of the humerus
preferably forms a resected portion. The resected portion has a
convex outer surface and an inner surface. The method further
includes engaging the convex outer surface of the resected portion
with a cut surface of the proximal portion of the humerus. The cut
surface of the proximal portion of the humerus and/or the inner
surface of the resected portion are optionally processed to form a
generally concave surface, such as by impacting. In one embodiment,
the inner surface of the resected portion is impacted into
engagement with the cut surface of the proximal portion of a
humerus. In one embodiment, the generally concave inner surface of
the resected portion forms a concave articular surface to receive
an interpositional implant. In another embodiment, a convex glenoid
implant is located in the scapula and engages with the concave
articular surface.
BRIEF DESCRIPTION OF THE SEVERAL VIEWS OF THE DRAWING
[0007] FIG. 1A is a schematic view of an intra-articular prosthesis
implanted in a patient's shoulder in accordance with an embodiment
of the present invention.
[0008] FIG. 1B is a schematic view of an alternate prosthesis
implanted in a patient's shoulder in accordance with an embodiment
of the present invention.
[0009] FIG. 2 is a schematic view of a cutting guide for a proximal
portion of a humerus in accordance with an embodiment of the
present invention.
[0010] FIG. 3 is a schematic view of a resected portion of the
proximal portion of the humerus in accordance with an embodiment of
the present invention.
[0011] FIG. 4 is a schematic view of a method of preparing a
resected proximal portion of the humerus in accordance with an
embodiment of the present invention.
[0012] FIG. 5 is a schematic view of a method and apparatus for
implanting the resected portion of the proximal portion of the
humerus in accordance with an embodiment of the present
invention.
[0013] FIG. 6 is a schematic view of a resected portion implanted
into a proximal portion of the humerus in accordance with an
embodiment of the present invention.
[0014] FIG. 7 is a schematic view of a resected portion implanted
into a proximal portion of the humerus using fasteners in
accordance with an alternate embodiment of the present
invention.
[0015] FIG. 8 is a schematic view of a resected portion implanted
into a proximal portion of the humerus using sutures in accordance
with an alternate embodiment of the present invention.
[0016] FIG. 9 is a schematic view of an interpositional implant
engaged with an implanted resected portion in accordance with the
present invention.
[0017] FIG. 10 is a schematic view of intra-articular prostheses
implanted in a patient's hand in accordance with an embodiment of
the present invention.
[0018] FIG. 11 is a schematic view of intra-articular prostheses
implanted in a patient's foot in accordance with an embodiment of
the present invention.
DETAILED DESCRIPTION OF THE INVENTION
[0019] FIG. 1A shows a schematic view of a prosthesis 10 including
a glenoid component 12, a humeral component 14 and an
interpositional implant 16. The glenoid component 12 is implanted
in the scapula S of the gleonid G. The method and apparatus of the
various embodiments of the present invention disclosed herein may
be used with a variety of glenoid components, such as for example
those disclosed in U.S. Pat. Nos. 7,033,396; 6,953,478; 6,761,740;
6,626,946; 5,702,447 and U.S. Publication Nos. 2004/0220673;
2005/0278030; 2005/0278031; 2005/0278032; 2006/0020344, which are
hereby incorporated by reference. Although the prosthesis 10 is
primarily discussed as being implanted in a patient's shoulder, the
prosthesis 10 may also be modified and implanted in other locations
of a patient's body without departing from the intended scope of
the present invention. For example, the prosthesis 10 may be
modified to be implanted in a patient's hip, ankle, hands, or
feet.
[0020] In the illustrated embodiment, the glenoid component 12
includes an articular member 18 with a generally concave articular
surface 20 that engages the interpositional implant 16. Given that
the articular member 18 is positioned immediately adjacent the
glenoid G, the interpositional implant 16 is remote from the
resected surface of the glenoid G in the sense that, if the
articular member 18 were omitted, the interpositional implant 16
would be directly juxtaposed with the glenoid G. Thus, on account
of the articular member 18, the interpositional implant 16 and the
humeral component 12 are laterally remote from the glenoid G,
limiting the risk of the humerus H interfering with the bottom of
the glenoid G, i.e. with the pillar P of the scapula S.
Alternatively, an articular member 18 may not be required within
the glenoid G. In this case, the interpositional implant 16 would
articulate directly with the glenoid G.
[0021] The humeral component 14 includes an articular member 24
formed from a resected portion 30 (shown in FIG. 3) of the proximal
humerus PH that is removed during processing of the humerus H. The
proximal humerus PH is preferably resected such that the resected
portion 30 is preferably a single, unitary piece. In this form, an
outer convex surface 58 of the resected portion 30 is implanted
into the proximal humerus PH as a single unit, rather than as
fragments.
[0022] Alternatively, the resected portion 30 can be formed from a
single piece or a plurality of pieces taken from the proximal
humerus PH or other locations in the patient's body. Implantation
of the resected portion 30 can be supplemented with bone graft
material, such as for example a puree of bone substance, bone
replacements, bone fillers, bone cements and/or bone adhesives, or
a combination thereof. The bone graft material can be formed from
the patient's bone, an allograft, a xenograft, or a combination
thereof. Various bone replacements, bone fillers, bone cements and
bone adhesives are disclosed in U.S. Pat. No. 6,692,563
(Zimmerman), which are hereby incorporated by reference. Various
additives can also be included with the resected portion,
including, but not limited to bone growth agents and pain
inhibitors.
[0023] As will be discussed further below, the resected portion 30
is prepared and impacted into the proximal humerus PH to form the
articular member 24 having a concave articular surface 32. The
preparation of the resected portion 30 can be performed ex vivo or
in situ.
[0024] In the illustrated embodiment, the humeral component 14
includes an optional stem 22 located in the medullary cavity M of
the humerus H. The proximal end 28 of the stem 22 supports the
resected portion 30 and optionally serves as an attachment member.
For example, a fastener 26 can optionally extend through the
resected portion 30 and engage the stem 22. It will be appreciated
that the stem 22 may be omitted entirely without departing from the
intended scope of the present invention.
[0025] The interpositional implant 16 is positioned between the
articular member 18 of the glenoid component 12 and the articular
member 24 of the humeral component 14. The radius of the
interpositional implant 16 is typically equal to or less than the
radii of the concave surfaces 20 and 32 of the articular member 18
of the glenoid component 12 and the articular member 24 of the
humeral component 14, respectively. When the interpositional
implant 16 is positioned between the glenoid component 12 and the
humeral component 14, as shown in FIG. 1A, the concave surfaces 20
and 32 are in mutual surface contact with the interpositional
implant 16, allowing articular movements of the patient's
shoulder.
[0026] In an alternate embodiment illustrated in FIG. 1B, the
interpositional implant 16 is eliminated and a glenoid component 18
with a convex articular surface 19 is substituted. The articular
member 24, created as outlines in FIG. 1A, engages directly with
the convex articular surface 19.
[0027] FIGS. 2-9 illustrate various embodiments for processing and
implanting the prosthesis 10 into the humerus H. It is to be
understood that the method of implanting the prosthesis 10
described hereinafter is merely a non-limiting illustrative example
of a method and instruments used to implant the prosthesis 10. In
other words, the method and the instruments specified hereinafter
can be used to implant prostheses of a broad range of structures,
of which, for example, the glenoid and/or humeral components 12, 14
consist of a plurality of metallic, plastic and/or ceramic-type
parts joined together. As previously mentioned, the interpositional
implant 16 may also articulate directly with the glenoid G such
that the glenoid component 12 is not included as part of the
prosthesis 10.
[0028] FIG. 2 is a schematic view of a cutting guide 34 positioned
over the proximal humerus PH. In order to prepare the proximal
humerus PH for resection, the soft parts (i.e. cartilage) of the
proximal humerus PH may optionally be removed using a deltopectoral
or supero-external approach.
[0029] The cutting guide 34 includes a bell-shaped body 36 secured
to a shaft 38. An interior surface of the body 36 has a concave
surface from which the main center of curvature pertains
substantially to an axis 40 from which the shaft 38 extends from
the body 36. The body 36 is designed to cover the upper portion of
the proximal humerus PH in the manner of a cap and is perforated to
give the surgeon a better view of the proximal humerus PH when
positioning the body 36. The body 36 is thus shaped to reproduce
approximately the surface features of the upper proximal humerus PH
of a normal anatomical humerus H. However, in practice, there will
be a range of a plurality of homothetic guiding instruments 34
having bodies 36 which have respective dimensions associated with
the size and the state of the patient's bones.
[0030] The shaft 38 of the cutting guide 34 is optionally provided
with a protruding tube 42 centered on the axis 40 and the main
center of curvature of the body 36. Once the body 36 is properly
positioned over the proximal humerus PH, a guide pin 44 having a
pointed distal end is introduced into the protruding tube 42 and
inserted into the proximal humerus PH. The guide pin 44 preferably
terminates before the cutting plane C-C'. The surgeon uses the
distal surface 27 on the body 36 located in the cutting plane C-C'
to resect the portion 30 from the proximal humerus PH.
Alternatively, the surgeon can cut free-hand without a
template.
[0031] FIG. 3 shows a schematic view of the resected portion 30 of
the proximal humerus PH. After the proximal humerus PH has been
resected, the proximal humerus PH has a cut surface 66 where the
resected portion 30 was removed. The resected portion 30 includes a
convex outer surface 58 and an inner cut surface 50 of cancellous
bone 52. In one embodiment, the resected portion 30 is prepared ex
vivo by impacting the inner cut surface 50 to compress the
cancellous bone 52 to form the generally inner convex surface 32.
As a result, the inner convex surface 32 is a layer of compacted
cancellous bone 52 pressed against the inner surface 54 of the
cortical bone 56.
[0032] In another embodiment, the resected portion 30 is prepared
ex vivo by removing the cancellous bone 52 from the cortical bone
56. As a result, the inner convex surface 32 is essentially the
inner surface 54 of the cortical bone 56. Either of these
procedures can also be performed in situ. That is, after the
resected portion 30 is engaged with the proximal humerus PH.
[0033] In some embodiments, the cut surface 66 of the proximal
humerus PH is prepared to receive the resected portion 30. A
hemispherical reaming instrument 64, shown in FIG. 4, is used to
form a concave surface 60 in the proximal humerus PH. The reaming
instrument 64 includes a convex body 68 having a plurality of teeth
70 to shape the cut surface 66 into the desired form. The concave
surface 60 is preferably the same shape as the outer convex surface
58 of the resected portion 30.
[0034] In another embodiment, the cut surface 66 (shown in dashed
lines) is compacted or carved to form the concave surface 60 on the
proximal humerus PH. Preparing the cut surface 66 of the proximal
humerus PH may be performed using a variety of other techniques
known in the art without departing from the intended scope of the
present invention. Small holes may optionally be drilled through
the concave surface 60 to enhance bone integration remodeling once
the resected portion 30 is reversed and implanted in the humerus
H.
[0035] FIG. 5 shows the resected portion 30 being impacted into
engagement with the concave surface 60 of the proximal humerus PH.
The resected portion 30 is positioned within the concave surface 60
such that the convex outer surface 58 engages the concave surface
60. An impacting instrument 78 is then used to drive the resected
portion 30 into the proximal humerus PH to form the articular
member 24 having a semi-spherical shape at the concave surface 60
of the proximal humerus PH. As the resected portion 30 is driven
into the proximal humerus PH, cancellous bone at each side of the
proximal humerus PH is compressed and forms to the shape of the
concave surface 60.
[0036] In an alternate embodiment illustrated in FIG. 6, the
resected portion 30 is compacted directly against the cut surface
66, without the reaming step shown in FIG. 4. By gradually
integrating the resected portion 30 into the proximal humerus PH, a
strong bony or fibrous-cartilaginous underlying support structure
having the concave surface 60 is created to support the articular
member 24. In addition, the resected portion 30 is used to isolate
the cancellous bone 67 in the humerus H from synovial fluids. The
resected portion 30 is preferably driven into the proximal humerus
PH as a single unit such that the resulting articular member 24 is
an integral piece and is not formed of fragmented pieces. The
articular member 24 has a shape of a metaphyseal cup formed to
cooperate with a variety of interpositional components, such as,
for example, a full sphere, a lens-type free interpositional
component, or a combination thereof. In one embodiment, the
articular member 24 may have a shape of approximately one-third of
a sphere.
[0037] FIG. 7 shows a schematic illustration of one embodiment of
attaching articular member 24 to the concave surface 60 of the
proximal humerus PH using a plurality of pins 80. The heads 82 of
the pins 80 are preferably flush with, or recessed below, the
concave inner surface 32. Various bone anchors, known in the art,
may also be used in place of the pins 80. The pins 80 may be formed
of various materials, including, but not limited to: metallic
components and polymeric components. In particular, the pins 80 may
be formed of bioresorbable polymers. The pins 80 are particularly
useful when the resected portion 30 includes a plurality of pieces
30A, 30B, 30C.
[0038] In one embodiment, a suture material 84 is optionally
attached to one or more of the pins 80. The suture material 84
extends through the proximal humerus PH to the opposite side and is
anchored to the cortical bone 86 using conventional techniques. The
suture material 84 operates as a tension member to retain the
resected portion 30 to the concave surface 60 of the proximal
humerus PH.
[0039] In an alternate embodiment illustrated in FIG. 8, the
resected portion 30 is attached to the proximal humerus PH using a
plurality of peripheral sutures 90. The sutures 90 may be formed of
various materials, including, but not limited to: metallic
components and polymeric components. In particular, the sutures 90
may be formed of bioresorbable polymers. The resected portion 30
may be fixed within the proximal humerus PH by any fixation
mechanism, or combination of fixation mechanisms, known in the art
without departing from the intended scope of the present
invention.
[0040] In one embodiment, a reinforcing structure 92, such as for
example reinforcing fibers, a three-dimensional porous matrix or
scaffold, is located between the concave surface 60 on the proximal
humerus PH and the resected portion 30. In the illustrated
embodiment, the reinforcing structure 92 is attached to the
cortical bone 86 of the proximal humerus PH by the sutures 90. In
one embodiment, the reinforcing structure 92 operates like a sling
to limit further penetration of the resected portion 30 into the
proximal humerus PH. In another embodiment, the reinforcing
structure 92 promotes in-growth between the proximal humerus PH and
the resected portion 30. Examples of such reinforcing structures
include a porous matrix, a scaffold, a reticulated bioceramic
framework, a structured porous tantalum and a synthetic fiber mesh.
Various porous matrices and scaffoldings are disclosed in U.S. Pat.
Nos. 4,479,271; 6,511,511; 6,605,117; 6,797,006; 6,902,584; and
7,250,550, which are hereby incorporated by reference. Although the
reinforcing structure 92 is discussed as being used in conjunction
with the resected portion 30, the reinforcing structure 92 may
alternatively be used in place of the resected portion 30 as an
articular surface for engaging the interpositional implant 16
(shown in FIGS. 1 and 9).
[0041] In another embodiment, the reinforcing structure 92 extends
beyond the sutures 90. The reinforcing structure 92 may be made of
any material, natural and synthetic, suitable for implantation.
Preferably the reinforcing structure 92 is flexible to permit
conformity with the proximal humerus PH. The reinforcing structure
92 material may also permit intraoperative cutting or other shaping
of the reinforcing structure 92 to fit a surgical site. For example
the reinforcing structure 92 may be intraoperatively shapeable by
cutting with scissors. The reinforcing structure 92 may include
natural tissues including fibrocartilage, fascia, pericardium,
and/or other natural tissues. The reinforcing structure 92 may
include synthetic materials including metals, polymers, ceramics,
hydrogels and/or other suitable materials. A polymer reinforcing
structure 92 may include resorbable and/or non-resorbable polymers.
Examples of resorbable polymers include polylactic acid polymers,
polyglycolic acid polymers, and/or other suitable resorbable
polymers. Examples of non-resorbable polymers include polyolefins,
polyesters, polyimides, polyamides, polyacrylates, polyketones,
and/or other suitable non-resorbable polymers. A metal reinforcing
structure 92 may include titanium, tantalum, stainless steel,
and/or other suitable metals and alloys thereof. For example metal
fibers may be woven into a porous flexible reinforcing structure
92.
[0042] The reinforcing structure 92 may be attached to the hard
and/or soft tissues of the proximal humerus PH by mechanical
fasteners 94, adhesives, tissue in-growth, and/or other suitable
attachment mechanism. The attachment mechanism may be permanent
and/or bioabsorbable. For example, the reinforcing structure 92 may
be screwed, pinned, sutured, or stapled to the bone and/or soft
tissue adjacent the joint. The reinforcing structure 92 may include
preformed openings for receiving fasteners. The reinforcing
structure 92 may include a reinforced edge to strengthen the
reinforcing structure 92 against pullout of fasteners. For example,
the edge may be reinforced by hemming, molding, braiding, embedding
a cord, and/or by other suitable reinforcement mechanism. The
reinforced edge may form a thicker portion of the reinforcing
structure 92.
[0043] FIG. 9 shows the interpositional implant 16 positioned
within the articular member 24 at the concave surface 60 of the
proximal humerus PH. Referring again also to FIG. 1A, once the
articular member 24 is fixed onto the proximal humerus PH or the
stem 22 and the articular member 18 is fixed onto the glenoid G,
the interpositional implant 16 is positioned between the articular
member 24 and the articular member 18. In one embodiment, the
interpositional implant 16 is a sphere or ball having a continuous
convex surface 104. The interaction of the convex surface 104 of
the interpositional implant 16 with the concave articular surface
32 of the articular member 24 and the concave surface 20 of the
articular member 18 allows articulation of the prosthesis 10. The
size of the interpositional implant 16 is selected such that the
convex surface 104 of the interpositional implant 16 is engageable
with both the concave surface 20 of the articular member 18 and the
concave articular surface 32 of the articular member 24. In one
embodiment, the interpositional implant 16 is formed of a polymeric
material, metal, ceramic, or a combination thereof. In one
embodiment, the interpositional implant 16 is coated with pyrolytic
carbon such as that described in U.S. Pat. No. 6,436,146 (Hassler
et al.) which is hereby incorporated by reference. Although FIG. 9
depicts the interpositional implant 16 as a sphere, the
interpositional implant 16 may have any shape having at least two
convex surfaces, such as a disc. The disc may articulate directly
with the glenoid G and the humerus H without the need for articular
member 18 of glenoid component 12 or articular member 24 of humeral
component 14. In another embodiment, the interpositional implant
may be replaced by a glenosphere formed of pyrolytic carbon. For
example, a convex surface of the glenosphere, or reversed glenoid
prosthesis, may be adapted to articulate directly with the
reversed, concave surface of the humerus H, and thus eliminate the
need for an interpositional implant.
[0044] As previously mentioned, the method of resecting natural
bone and compacting the resected surface of the natural bone with
the resected portion to form a concave articular surface for
engagement with a convex articular surface of an interpositional
implant to repair or replace a damaged joint is not limited to
repairing or replacing a damaged shoulder.
[0045] FIG. 10 shows a hand having a first interpositional implant
100 implanted between metacarpal 102 and proximal phalange 104. The
distal end 120 of the metacarpal 102 is resected and processed in a
manner similar to the resection and processing of the glenoid and
humeral components 12 and 14 (shown in FIG. 1A) described above, to
create a concave articular surface 122. In the illustrated
embodiment, proximal end 124 of the proximal phalange 104 is also
resected and processed to create concave articular surface 126.
[0046] FIG. 10 also illustrates a second interpositional implant
106 implanted between metacarpal 108 and proximal phalange 110, and
a third interpositional implant 112 implanted between proximal
phalange 114 and intermediate phalange 116. The bones 102, 104,
108, 110, 114 and 116 adjacent the respective interpositional
implants 100, 106 and 112 are preferably resected and processed in
a manner similar to the resection and processing of the glenoid and
humeral components 12 and 14 (shown in FIG. 1A) described above. In
some embodiments, a natural concave articular surface of one of the
bones at the intersection, such as for example on the proximal end
128 of the proximal phalange 110, may be sufficient to retain the
interpositional implant 106, making resection unnecessary. The
interpositional implants 100, 106 and 112 interact and function
with the resected bones in a manner similar to the interpositional
implant 16 described above.
[0047] In another embodiment, the proximal end 130 of the proximal
phalange 114 is resected and processed as discussed herein. The
naturally convex surface 132 of the metacarpal 134 engages directly
with the concave articular surface 136, without the need for an
interpositional implant.
[0048] As can be seen in FIG. 10, depending on the joint being
repaired or replaced, the shape of the interpositional implants
100, 106 and 112 may be modified so that they are easily
implantable between their respective components or bones. Although
FIG. 10 depicts interpositional implants between metacarpal bones
and proximal phalanges and an interpositional implant between a
proximal phalange and a middle phalange, an interpositional implant
may be positioned at any joint in the hand, for example, between a
middle phalange bone and a distal phalange bone or between the
trapezium or scaphoid and a metacarpal bone.
[0049] FIG. 11 shows a foot having a first interpositional implant
200 implanted between a metatarsal 202 and a proximal phalange 204
and a second interpositional implant 206 implanted between the
proximal phalange 204 and a distal phalange 208. The bones 202, 204
and 208 adjacent the respective interpositional implants 202 and
206 are resected and processed in a manner similar to the resection
and processing of the glenoid and humeral components 12 and 14
(shown in FIG. 1A) described above. Likewise, the interpositional
implants 202 and 206 interact and function with the resected bones
in a manner similar to the interpositional implant 16 described
above.
[0050] Similar to the interpositional implants 100, 106 and 112
depicted in FIG. 10, the shape of the interpositional implants 202
and 206 may be modified so that they correspond to the shape of the
resected bone structures within the foot. Although FIG. 11 depicts
an interpositional implant between a metatarsal bone and a proximal
phalange and an interpositional implant between a proximal phalange
and a middle phalange, an interpositional implant may be positioned
at any joint in the foot, for example, between a proximal phalange
and a middle phalange or between a middle phalange and a distal
phalange. Any of the variations disclosed herein can be used with
the embodiments of FIGS. 10 and 11, such as for example, the
reinforcing structure or fasteners.
[0051] Various modifications and additions can be made to the
exemplary embodiments discussed without departing from the scope of
the present invention. For example, while the embodiments
descriconcave articular surface above refer to particular features,
the scope of this invention also includes embodiments having
different combinations of features and embodiments that do not
include all of the descriconcave articular surface features.
Accordingly, the scope of the present invention is intended to
embrace all such alternatives, modifications, and variations as
fall within the scope of the claims, together with all equivalents
thereof.
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