U.S. patent application number 13/790633 was filed with the patent office on 2014-01-02 for modified glenoid components and methods of installing same.
This patent application is currently assigned to DePuy Products, Inc.. The applicant listed for this patent is DEPUY PRODUCTS, INC.. Invention is credited to Jason M. Chavarria, Kyle E. Lappin.
Application Number | 20140005789 13/790633 |
Document ID | / |
Family ID | 48699617 |
Filed Date | 2014-01-02 |
United States Patent
Application |
20140005789 |
Kind Code |
A1 |
Chavarria; Jason M. ; et
al. |
January 2, 2014 |
Modified Glenoid Components and Methods of Installing Same
Abstract
A glenoid component for securement to a glenoid surface of a
scapula comprises a body portion having a first surface adapted to
contact the glenoid surface of a scapula and a second surface
configured to receive the head portion of a humerus. The glenoid
component further includes an anchor peg for penetrating the
glenoid surface of the scapula so as to secure the body portion to
the glenoid surface of the scapula. The anchor peg includes a
cylindrical shaft extending from the first surface of the body
portion and a fin secured to and extending outwardly from the
cylindrical shaft. The glenoid component further includes a feature
that prevents rotation of the glenoid component.
Inventors: |
Chavarria; Jason M.;
(Warsaw, IN) ; Lappin; Kyle E.; (Warsaw,
IN) |
|
Applicant: |
Name |
City |
State |
Country |
Type |
DEPUY PRODUCTS, INC. |
Warsaw |
IN |
US |
|
|
Assignee: |
DePuy Products, Inc.
Warsaw
IN
|
Family ID: |
48699617 |
Appl. No.: |
13/790633 |
Filed: |
March 8, 2013 |
Related U.S. Patent Documents
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Application
Number |
Filing Date |
Patent Number |
|
|
61665633 |
Jun 28, 2012 |
|
|
|
Current U.S.
Class: |
623/19.11 |
Current CPC
Class: |
A61F 2/4081 20130101;
A61F 2002/30113 20130101; A61F 2002/30881 20130101; A61F 2002/30878
20130101; A61F 2002/30884 20130101; A61B 17/1684 20130101; A61F
2002/30891 20130101; A61F 2002/30154 20130101; A61F 2002/30571
20130101; A61B 17/1604 20130101 |
Class at
Publication: |
623/19.11 |
International
Class: |
A61F 2/40 20060101
A61F002/40 |
Claims
1. A glenoid component for securement to a glenoid surface of a
scapula so as to provide a bearing surface for a head portion of a
humerus, the glenoid component comprising: a body portion having
(i) a first surface adapted to contact the glenoid surface of a
scapula and (ii) a second surface configured to receive the head
portion of the humerus; and an anchor peg for penetrating the
glenoid surface of the scapula so as to secure the body portion to
the glenoid surface of the scapula, wherein the anchor peg includes
(i) a cylindrical shaft extending from the first surface of the
body portion and (ii) a fin secured to and extending outwardly from
the cylindrical shaft, the fin being generally square-shaped.
2. The glenoid component of claim 1, further including a plurality
of generally square-shaped fins secured to and extending outwardly
from the cylindrical shaft of the anchor peg.
3. The glenoid component of claim 2, wherein the generally
square-shaped fins have rounded corners.
4. The glenoid component of claim 3, wherein the anchor peg is
adapted for insertion into a hole within a glenoid surface of a
scapula and wherein the fins have a width that is greater than a
width or diameter of a hole in which the anchor peg is inserted and
further wherein the fins are configured to prevent rotation of the
glenoid component within the glenoid surface.
5. The glenoid component of claim 2, wherein side edges of the fins
are configured to have an interference with a wall forming a hole
in which the anchor peg is inserted of between about 0.25
millimeters and about 2 millimeters.
6. The glenoid component of claim 5, wherein rounded corners of the
fins are configured to have an interference with the wall forming
the hole in which the anchor peg is inserted of between about 0.5
millimeters and about 3 millimeters, and wherein the interference
between the side walls and the rounded corners with the wall
forming the hole prevent rotation of the glenoid component.
7. The glenoid component of claim 2, wherein the anchor peg is
configured for insertion into a generally square-shaped hole in the
glenoid surface of the scapula.
8. A glenoid component for securement to a glenoid surface of a
scapula so as to provide a bearing surface for a head portion of a
humerus, the glenoid component comprising: a body portion having
(i) a first surface adapted to contact the glenoid surface of a
scapula and (ii) a second surface configured to receive the head
portion of the humerus; an anchor peg for penetrating the glenoid
surface of the scapula so as to secure the body portion to the
glenoid surface of the scapula, wherein the anchor peg includes (i)
a cylindrical shaft extending from the first surface of the body
portion and (ii) a fin secured to and extending outwardly from the
cylindrical shaft; and at least one gusset secured to and extending
downwardly from the first surface of the body portion and secured
to and extending outwardly from the cylindrical shaft of the anchor
peg.
9. The glenoid component of claim 8, wherein an angled edge is
formed by the gusset and extends between the first surface of the
body portion and the anchor peg.
10. The glenoid component of claim 9, wherein the angled edge of
the gusset is configured to be driven into the glenoid surface of
the scapula to prevent rotation of the glenoid component.
11. The glenoid component of claim 10, further including a
plurality of gussets secured to and extending downwardly from the
first surface of the body portion and secured to and extending
outwardly from the cylindrical shaft of the anchor peg.
12. The glenoid component of claim 11, wherein the gussets are
orthogonal to the first surface of the body portion and the
cylindrical shaft of the anchor peg.
13. The glenoid component of claim 12, further including four
gussets spaced about a longitudinal axis of the anchor peg with
about ninety degrees between adjacent gussets.
14. The glenoid component of claim 13, wherein the gussets are
configured to be driven into the glenoid surface of the scapula to
prevent rotation of the glenoid component.
15. A glenoid component for securement to a glenoid surface of a
scapula so as to provide a bearing surface for a head portion of a
humerus, the glenoid component comprising: a body portion having
(i) a first surface adapted to contact the glenoid surface of a
scapula and (ii) a second surface configured to receive the head
portion of the humerus; an anchor peg for penetrating the glenoid
surface of the scapula so as to secure the body portion to the
glenoid surface of the scapula, wherein the anchor peg includes (i)
a cylindrical shaft extending from the first surface of the body
portion and (ii) a fin secured to and extending outwardly from the
cylindrical shaft, wherein the fin includes at least one cutout
configured to allow the fin to deflect outwardly along a hole in
which the glenoid component is secured, thereby preventing rotation
of the glenoid component.
16. The glenoid component of claim 15, further including first and
second opposing cutouts, wherein each of the cutouts includes a
first leg and a second leg forming generally triangular
cutouts.
17. The glenoid component of claim 16, wherein the cutouts are
symmetrical about an axis that bisects the fins.
18. The glenoid component of claim 16, wherein the body portion of
the glenoid component is generally circular.
19. The glenoid component of claim 15, further including first and
second opposing cutouts, wherein each of the cutouts is generally
U-shaped.
20. A tool for preparing a glenoid surface of a scapula, the tool
comprising: a handle; and a punch operatively connected to the
handle, wherein the fin punch includes a plate having a cylinder
extending from the disc and at least one gusset extending outwardly
from the cylinder.
21. The tool of claim 20, further including four gussets extending
outwardly from the cylinder.
22. The tool of claim 21, wherein the gussets are generally
orthogonal to the disc and extend outwardly and are orthogonal to
the cylinder and wherein each of the four gussets is disposed about
90 degrees from an adjacent gusset.
Description
CROSS-REFERENCE TO RELATED U.S. PATENT APPLICATION
[0001] This application claims priority under 35 U.S.C. .sctn.119
to U.S. Patent Application No. 61/665,633, entitled "MODIFIED
GLENOID COMPONENTS AND METHODS OF INSTALLING SAME," which was filed
on Jun. 28, 2012. The disclosure of such application is
incorporated herein by reference.
TECHNICAL FIELD
[0002] The present disclosure relates generally to a glenoid
component, and more particularly, to a glenoid component that
resists rotation and pullout and a method of implanting the glenoid
component.
BACKGROUND
[0003] During the lifetime of a patient, it may be necessary to
perform a total shoulder replacement procedure on the patient as a
result of, for example, disease or trauma. In a total shoulder
replacement procedure, a humeral component having a head is
utilized to replace the natural head of the arm bone or humerus.
The humeral component typically has an elongated intramedullary
stem that is utilized to secure the humeral component to the
patient's humerus. In such a total shoulder replacement procedure,
the natural glenoid surface of the scapula is resurfaced or
otherwise replaced with a glenoid component which provides a
bearing surface for the head of the humeral component.
[0004] Glenoid components generally include a body that defines a
bearing surface for receiving the head of the humeral component and
a number of attachment pegs integrally formed with the body. The
attachment pegs are inserted and thereafter secured into a
corresponding number of holes that are drilled in the glenoid
surface of the scapula by use of bone cement. The pegs prevent
rotation of the glenoid component.
SUMMARY
[0005] According to an illustrative embodiment, a glenoid component
for securement to a glenoid surface of a scapula so as to provide a
bearing surface for a head portion of a humerus comprises a body
portion and an anchor peg. The body portion includes a first
surface adapted to contact the glenoid surface of a scapula and a
second surface configured to receive the head portion of the
humerus. The anchor peg is for penetrating the glenoid surface of
the scapula so as to secure the body portion to the glenoid surface
of the scapula. The anchor peg includes a cylindrical shaft
extending from the first surface of the body portion and a fin
secured to and extending outwardly from the cylindrical shaft, the
fin being generally square-shaped.
[0006] The glenoid component includes a plurality of generally
square-shaped fins secured to and extending outwardly from the
cylindrical shaft of the anchor peg.
[0007] The fins are generally square-shaped and have rounded
corners.
[0008] The anchor peg is adapted for insertion into a hole within a
glenoid surface of a scapula and the fins have a width that is
greater than a width or diameter of a hole in which the anchor peg
is inserted. The fins are configured to prevent rotation of the
glenoid component within the glenoid surface.
[0009] Side edges of the fins are configured to have an
interference with a wall forming a hole in which the anchor peg is
inserted of between about 0.25 millimeters and about 2
millimeters.
[0010] Rounded corners of the fins are configured to have an
interference with the wall forming the hole in which the anchor peg
is inserted of between about 0.5 millimeters and about 3
millimeters. The interference between the side walls and the
rounded corners with the wall forming the hole prevent rotation of
the glenoid component.
[0011] The anchor peg is configured for insertion into a generally
square-shaped hole in the glenoid surface of the scapula.
[0012] According to a further illustrative embodiment, a glenoid
component for securement to a glenoid surface of a scapula so as to
provide a bearing surface for a head portion of a humerus comprises
a body portion, an anchor peg, and at least one gusset. The body
portion includes a first surface adapted to contact the glenoid
surface of a scapula and a second surface configured to receive the
head portion of the humerus. The anchor peg is for penetrating the
glenoid surface of the scapula so as to secure the body portion to
the glenoid surface of the scapula. The anchor peg includes a
cylindrical shaft extending from the first surface of the body
portion and a fin secured to and extending outwardly from the
cylindrical shaft. The at least one gusset is secured to and
extending downwardly from the first surface of the body portion and
secured to and extending outwardly from the cylindrical shaft of
the anchor peg.
[0013] An angled edge is formed by the gusset and extends between
the first surface of the body portion and the anchor peg.
[0014] The angled edge of the gusset is configured to be driven
into the glenoid surface of the scapula to prevent rotation of the
glenoid component.
[0015] The glenoid component includes a plurality of gussets
secured to and extending downwardly from the first surface of the
body portion and secured to and extending outwardly from the
cylindrical shaft of the anchor peg.
[0016] The gussets are orthogonal to the first surface of the body
portion and the cylindrical shaft of the anchor peg.
[0017] Four gussets are spaced about a longitudinal axis of the
anchor peg with about ninety degrees between adjacent gussets.
[0018] The gussets are configured to be driven into the glenoid
surface of the scapula to prevent rotation of the glenoid
component.
[0019] According to another illustrative embodiment, a glenoid
component for securement to a glenoid surface of a scapula so as to
provide a bearing surface for a head portion of a humerus comprises
a body portion and an anchor peg. The body portion includes a first
surface adapted to contact the glenoid surface of a scapula and a
second surface configured to receive the head portion of the
humerus. The anchor peg is for penetrating the glenoid surface of
the scapula so as to secure the body portion to the glenoid surface
of the scapula. The anchor peg includes a cylindrical shaft
extending from the first surface of the body portion and a fin
secured to and extending outwardly from the cylindrical shaft. The
fin includes at least one cutout configured to allow the fin to
deflect outwardly along a hole in which the glenoid component is
secured, thereby preventing rotation of the glenoid component.
[0020] The fin includes first and second opposing cutouts, wherein
each of the cutouts includes a first leg and a second leg forming
generally triangular cutouts.
[0021] The cutouts are symmetrical about an axis that bisects the
fins.
[0022] The body portion of the glenoid component is generally
circular.
[0023] Other aspects and advantages of the present disclosure will
become apparent upon consideration of the following drawings and
detailed description, wherein similar structures have similar
reference numbers.
BRIEF DESCRIPTION OF THE DRAWINGS
[0024] The detailed description particularly refers to the
following figures, in which:
[0025] FIG. 1 is a top perspective view of a first embodiment of a
glenoid component;
[0026] FIG. 2 is a bottom perspective view of the glenoid component
of FIG. 1;
[0027] FIG. 3 is a side elevational view of a second embodiment of
a glenoid component;
[0028] FIG. 4 is a bottom perspective view of the glenoid component
of FIG. 3;
[0029] FIG. 5 is a bottom perspective view of a third embodiment of
a glenoid component;
[0030] FIG. 6 is a bottom perspective view of a fourth embodiment
of a glenoid component;
[0031] FIG. 7 is a bottom elevational view of the glenoid component
of FIG. 6 and showing a shape of fins that extend outwardly from an
anchor peg of the glenoid component;
[0032] FIG. 8 is a perspective view depicting a glenoid surface of
a scapula with a hole for securing a glenoid component to the
glenoid surface;
[0033] FIG. 9 is a partial exploded perspective view depicting the
glenoid component of FIG. 1 secured within the glenoid surface of
FIG. 8 and further showing a humeral component;
[0034] FIG. 10 is a cross-sectional view taken generally along the
lines 10-10 of FIG. 9 and depicting deflection of fins of the
glenoid component of FIGS. 1 and 2 after securing the glenoid
component within the glenoid surface;
[0035] FIG. 11 is a cross-sectional view taken generally along the
lines 11-11 of FIG. 9 and depicting a sample level of interference
between the fins of the glenoid component of FIGS. 1 and 2 and
walls forming the hole formed within the glenoid surface;
[0036] FIG. 12 is a cross-section view similar to that of FIG. 10
and depicting the glenoid component of FIG. 3 secured within the
glenoid surface;
[0037] FIG. 13 is a perspective view of a tool that may be used to
prepare the glenoid surface prior to securing the glenoid component
of FIG. 3 thereto;
[0038] FIG. 14 is a diagrammatic view of an orthopaedic surgical
tool having a cutting bit configured to make a square-shaped hole;
and
[0039] FIG. 15 is a perspective view of the cutting bit of the
orthopaedic surgical tool of FIG. 14.
DETAILED DESCRIPTION OF THE DRAWINGS
[0040] While the concepts of the present disclosure are susceptible
to various modifications and alternative forms, specific exemplary
embodiments thereof have been shown by way of example in the
drawings and will herein be described in detail. It should be
understood, however, that there is no intent to limit the concepts
of the present disclosure to the particular forms disclosed, but on
the contrary, the intention is to cover all modifications,
equivalents, and alternatives falling within the spirit and scope
of the invention as defined by the appended claims.
[0041] Terms representing anatomical references, such as anterior,
posterior, medial, lateral, superior, inferior, etcetera, may be
used throughout this disclosure in reference to both the
orthopaedic implants described herein and a patient's natural
anatomy. Such terms have well-understood meanings in both the study
of anatomy and the field of orthopaedics. Use of such anatomical
reference terms in the specification and claims is intended to be
consistent with their well-understood meanings unless noted
otherwise.
[0042] Referring now to the figures, a first embodiment of a
polymer glenoid component 20 is depicted in FIGS. 1 and 2. The
glenoid component 20 includes a body 22 having a generally convex
surface 24 and a generally concave surface 26 opposite the convex
surface 24. The convex surface 24 generally abuts or otherwise
contacts at least a portion of the glenoid surface of the scapula.
The body 22 of the glenoid component 20 generally has a shaped that
is generally circular, such that the concave surface 26 generally
forms a spherical surface. In this manner, the concave surface 26
of the body 22 provides a smooth bearing surface upon which the
head 28 articulates and which generally matches the shape of the
spherical head 28.
[0043] The glenoid component 20 also includes an anchor peg 40
secured to and extending generally orthogonal to the convex surface
24 of the body 22. As shown in FIGS. 1 and 2, the anchor peg 40
includes a cylindrical shaft 42 and a tapered head 46 at an end of
the cylindrical shaft 42 that functions as a lead-in to facilitate
insertion into a hole 48 drilled or otherwise formed in a glenoid
surface 50 (as shown in FIGS. 8 and 9) of a patient's scapula 52.
The anchor peg 40 may include a first cylindrical shaft segment
extending from the convex surface 24 and having a first diameter
and a second cylindrical shaft segment extending from the first
cylindrical shaft segment and having a second diameter less than
the first diameter, as seen in FIGS. 1 and 2. Alternatively, the
anchor peg 40 may have a single diameter throughout a length of the
cylindrical shaft 42.
[0044] The anchor peg 40 further includes a plurality of flexible
radial fins 60 extending outwardly from an end 62 of the anchor peg
40. The fins 60 function to secure the glenoid component 20 within
the glenoid surface 50. In addition, the flexible and deformable
nature of the radial fins 60 extending from the anchor peg 40 allow
the fins 60 to deform upon insertion of the anchor peg 40 into the
hole 48, thereby creating resistance to extraction of the anchor
peg 40 from the hole 48 once fully inserted therein.
[0045] The fins 60 of glenoid component 20, as best seen in FIGS. 1
and 2, are generally square-shaped with rounded corners 62. The
fins 60 have a size and shape that creates an interference with
walls forming the hole 48 that prevents easy removal of the glenoid
component 20 from the glenoid surface 50 and prevents rotation of
the glenoid component 20 without the use of a stabilizing peg, as
will be discussed in greater detail hereinafter.
[0046] A second embodiment of a glenoid component 80 is depicted in
FIGS. 3 and 4. The glenoid component 80 is similar to the glenoid
component 20 of FIGS. 1 and 2 in that it includes a body 82 with
opposing generally convex and generally concave surfaces 84, 86.
The glenoid component 20 also includes an anchor peg 90 with a
cylindrical shaft 91 and a tapered end 92. One manner in which the
glenoid component 80 is different from the glenoid component 20 of
the first embodiment is that it includes a plurality of generally
circular fins 96 extending outwardly from an end 98 of the anchor
peg 90.
[0047] Referring again to FIGS. 3 and 4, the glenoid component 80
further includes a plurality of gussets 100 extending downwardly
from the convex surface 84 and outwardly from the anchor peg 90
adjacent the convex surface 84 of the body 82. The gussets 100 are
also generally orthogonal to the convex surface 84 and the anchor
peg 90 and extend outwardly from the peg 90 a distance greater than
the fins 96 extend from the peg 90. An outer angled edge 102 of
each gusset 100 extends between and is integrally attached to the
convex surface 84 and the anchor peg 90. The gussets are spaced
about a longitudinal axis 104 of the anchor peg 90 with about
ninety degrees between adjacent gussets 100.
[0048] When the glenoid component 80 is installed within the
glenoid surface 50, the gussets 100 are pressed into the glenoid
surface 50 surrounding the anchor peg 90 and below the convex
surface 84 of the body 82, thereby preventing rotation of the
glenoid component 80 without the use of a stabilizing peg.
Installation and functionality of the glenoid component will be
discuss in greater detail below with respect to FIG. 13.
[0049] While four gussets 100 are depicted with respect to the
embodiment of the glenoid component 80 of FIGS. 3 and 4, one or
more gussets 100 may be utilized. In one embodiment, a single
gusset 100 may be utilized. In another embodiment, eight gussets
100 may be utilized. The number of gussets 100 utilized may be
determined based on the ability of those gussets 100 to prevent
rotation of the glenoid component 80, the cost of additional
gussets 100, and/or other factors.
[0050] A third embodiment of a glenoid component 120 is shown in
FIG. 5. The glenoid component 120 is similar to the glenoid
component 80 of FIGS. 3 and 4 and, thus, similar features will be
numbered similarly. The main difference is that the glenoid
component 120 does not include gussets, but rather, includes a
stabilizing peg 122 extending outwardly from the convex surface 84.
The stabilizing peg 122 is spaced between the anchor peg 90 and an
outer edge 124 of the body 82. While one stabilizing peg 122 is
shown, other stabilizing pegs 122 may be spaced about the convex
surface 84.
[0051] The stabilizing peg 122 prevents the body 82 of the glenoid
component 120 from moving a plane perpendicular to the anchor peg
90 and prevent rotational movement of the glenoid component 120.
Generally, the stabilizing peg 122 is shorter than the anchor peg
90. Moreover, if multiple stabilizing pegs 122 are utilized, one or
more of the stabilizing pegs 122 may be shorter than the others,
although other configurations may be used.
[0052] While the body 82, the anchor peg 90, and the stabilizing
peg 122 of the glenoid component 120 are shown as being integral,
one or more of the anchor peg 90 or stabilizing peg 122 may be
separately secured to the body 82. As one skilled in the art would
understand, any number of anchor pegs 90 or stabilizing pegs 122
may be utilized, the anchor peg 90 may include any features that
aid in inserting the anchor peg 90 into a hole or retaining the
anchor peg 90 within a hole, and/or the placement of the anchor
peg(s) 90 and/or stabilizing peg(s) 122 may be modified without
departing from the scope of the present disclosure.
[0053] In the embodiment of FIG. 5, one or more secondary holes
(not shown) would be formed within the glenoid surface 50 and
spaced between the hole 48 and an outer edge of the glenoid surface
50. The secondary holes may have a size and shape that conforms to
the stabilizing peg(s) 122.
[0054] A fourth embodiment of a glenoid component 150 is depicted
in FIG. 6. The glenoid component 150 is similar to the glenoid
component 80 of FIGS. 3 and 4. In particular, the glenoid component
150 includes a similar body 82 with convex and concave surfaces 84,
86 and an anchor peg 90 having a cylindrical shaft 91 and a tapered
end 92 and extending outwardly and transversely to the convex
surface 84. The glenoid component 150 further includes a plurality
of fins 152 extending outwardly from an end of the anchor peg 90.
Upon insert of the anchor peg 90 into the hole 48, portions of the
fins 152 deflect outwardly (toward an opening of the hole 48),
thereby preventing rotation of the glenoid component 150 without
the use of a stabilizing peg.
[0055] Each of the fins 152 is generally disc-shaped and includes
two opposing cutouts 154. The cutouts 154 are generally triangular
in shape and are generally symmetrical about an axis 155 that
bisects the fins 152. Optionally, the cutouts 154 may be
asymmetrical. Each cutout 154 includes first and second legs 156,
158 that extend at an angle A with respect to one another. The
first leg 156 of each cutout 154 extends at an angle B with respect
to a line 160 tangent to an outer end of the first leg 156 and the
second leg 158 of each cutout 154 extends at an angle C with
respect to a line 162 tangent to an outer end of the second leg
158. Optionally, the cutouts 154 may be formed of another shape,
for example, square-shaped or U-shaped. The cutouts 154 allow bone
to grow between the fins 152 in two planes. While two cutouts 154
are depicted, any number of cutouts 154 is possible.
[0056] The glenoid components shown and described herein may be
made of a polymeric material, for example, a polyethylene. One
example of a suitable polyethylene is ultrahigh molecular weight
polyethylene (UHMWPE). In addition to polymers, the glenoid
components may be made from ceramic, metal, or a composite
material. Examples of these materials include alumina, zirconia,
and alumina/zirconia composite or composite material.
[0057] A method of securing the glenoid component 20 of FIGS. 1 and
2 to the glenoid surface 50 of the scapula 52 will now be discussed
in detail with reference to FIGS. 8-11. A drill is used to bore the
hole 48 through the glenoid surface 50 and into the scapula 52 in a
manner known in the art and, thereafter, the anchor peg 40 of the
glenoid component 20 is press fit or otherwise interference fit
into the hole 48. During installation, the rounded corners 62
and/or side edges 170 between the rounded corners 62 of the
square-shaped fins 96 deflect outwardly (or toward an opening of
the hole 48), thereby creating an interference with a wall forming
the hole that prevents rotational movement of the glenoid component
150 and prevents the glenoid component 20 from moving in a plane
perpendicular to the anchor peg 40. While the hole 48 is depicted
herein as having a circular cross-section, the hole may optionally
have different cross-sections for any of the embodiments disclosed
herein, for example, a square-shaped cross section.
[0058] As can be seen in FIG. 11, which depicts a range of
interference between the fins 60 and a wall forming the hole 48,
the square shape of the fins 60 provides a greater interference at
the corners 62 of the fins 60 than at the side edges 170 of the
fins 96. In one embodiment, an interference between the side edges
170 of the fins 60 and the wall of the hole 48 is between about
0.25 millimeters (mm) and about 2 mm and an interference between
the corners 62 of the fins 60 and the wall of the hole 48 is
between about 0.5 mm and about 3 mm. In another embodiment, a width
of the square fins 60 is greater than a diameter of the hole
48.
[0059] The deflection of the fins 60 upon insertion of the glenoid
component 20 into the hole 48 is depicted in FIG. 10. In
particular, the corners 62 of the fins 60 are deflected outwardly a
greater distance than the side edges 170 of the fins 60 are
deflected due to the difference in overall interference.
[0060] If the hole in which the glenoid component 20 is installed
has a square-shaped cross-section, a hole 172 maybe be created
utilizing a tool having a bit 174 with a general profile of a
Reuleux triangle 176, as seen in FIGS. 14 and 15. In particular, a
Reuleux triangle 176 is created by starting with an equilateral
triangle 178 with sides of length S. With a radius equal to S and a
center at a vertice of the triangle 178, three arcs 180 are drawn
to form the Reuleux triangle 176. The bit 174, as noted above, has
an outer profile that forms the Reuleux triangle 176, such that,
when the bit is rotated about a circle 182 starting at a center 184
of the equilateral triangle 178, a square-shaped hole 172 with
rounded corners is formed. The glenoid component 20 is secured in
the same manner when the hole 172 with a square-shaped
cross-section is used. A length of a side of the square forming the
fins 96 may be greater than a length of a side of the square
forming the hole 172, thereby forming an interference fit. Upon
insertion of the glenoid component 20, the rounded corners 62 and
the side edges 170 of the fins 96 deflect outwardly (toward an
opening of the hole 172). The square shapes would prevent rotation
of the glenoid component 20.
[0061] Methods of securing the glenoid component 80 of FIGS. 3 and
4 to the glenoid surface 50 of the scapula 52 will now be discussed
in detail with reference to FIGS. 12 and 13. A hole 48 is bored
into the glenoid surface 50 of the scapula 52 in any manner known
in the art. Thereafter, a tool 200 as shown in FIG. 13, may be used
to create slots within the glenoid surface 50 surrounding the hole
48. The tool 200 generally includes a handle 202, a rod 204
extending from an end 206 of the handle 202, and a punch 208
attached to an end 210 of the rod 204. The punch 208 includes a
plate, for example, a disc 212 having a cylinder 214 extending from
a surface 216 of the disc 212 opposite the rod 204. The cylinder
214 is shaped and sized to have a diameter that interferes with the
hole 48. In particular, the cylinder 214 has a diameter that is
larger than a diameter than the hole 48 and smaller than a diameter
of the fins of a glenoid component that fits within the hole 48.
Triangular gussets 218 extend outwardly from the cylinder 214. The
gussets 218 are similar in size, shape, and number to the gussets
100 of the glenoid component 80. In particular, the gussets 218 are
generally orthogonal to the disc 212 and extend outwardly and are
generally orthogonal to the cylinder 214. Each gusset 218 is also
disposed about 90 degrees around the cylinder 214 from an adjacent
gusset 218. Should more or less gussets 100 be formed within a
glenoid component, the tool 200 may be modified accordingly.
[0062] The tool 200 is grasped by the handle 202, the cylinder 214
of the tool 200 is inserted into the hole 48, and pressure is
exerted on the tool 200 toward the glenoid surface 50, thereby
creating slots in the glenoid surface 50 corresponding to the
gussets 218. The anchor peg 90 of the glenoid component 80 may
thereafter be inserted into the hole 48, in the manner described
with respect to the first embodiment, until the gussets 218 are
disposed within the slots created by the tool 200.
[0063] The glenoid component 80 may be secured to the glenoid
surface 50 without the use of the tool 200. In such an embodiment,
the anchor peg 90 of the glenoid component 80 would be inserted
into the hole 48 and the gussets 100 would be driven into the
glenoid surface 50, thereby creating the slots in which the gussets
100 are disposed.
[0064] The glenoid component 120 of FIG. 5 is secured to the
glenoid surface 50 in a manner similar to that of the glenoid
component 20 except that a secondary hole is created and, during
installation of the glenoid component 120, the stabilizing peg 122
is aligned with and inserted into the secondary hole.
[0065] The anchor peg 90 of the glenoid component 150 of FIG. 6 is
also secured to the glenoid surface 50 in a manner similar to that
of the glenoid component 20. During installation, the cutouts 154
in the fins 152 of the glenoid component 150 allow the fins 152 to
deflect outwardly (or toward an opening of the hole 48), thereby
creating an interference with a wall forming the hole that prevents
rotational movement of the glenoid component 150 and movement of
the glenoid component 150 in a plane perpendicular to the glenoid
component 150.
[0066] The configurations of the fins and/or gussets as shown and
described herein eliminate the need for the use of bone cement to
secure the anchor peg to the glenoid surface 50 of the scapula 52,
thereby reducing the complexity of a typical shoulder replacement
procedure.
[0067] While the glenoid components shown in the figures and
described in detail include have a generally circular
configuration, as described above, the principles of the present
disclosure may be implemented within a glenoid component having any
configuration, for example, oval-shaped. One advantage provided by
the glenoid components having a circular configuration is that the
glenoid component does not have to be aligned in a specific
position or orientation.
[0068] As will become apparent from reading the present
specification, any of the features of any of the embodiments
disclosed herein may be incorporated within any of the other
embodiments without departing from the scope of the present
disclosure.
[0069] While the disclosure has been illustrated and described in
detail in the drawings and foregoing description, such an
illustration and description is to be considered as exemplary and
not restrictive in character, it being understood that only
illustrative embodiments have been shown and described and that all
changes and modifications that come within the spirit of the
disclosure are desired to be protected.
[0070] There are a plurality of advantages of the present
disclosure arising from the various features of the apparatus,
system, and method described herein. It will be noted that
alternative embodiments of the apparatus, system, and method of the
present disclosure may not include all of the features described
yet still benefit from at least some of the advantages of such
features. Those of ordinary skill in the art may readily devise
their own implementations of the apparatus, system, and method that
incorporate one or more of the features of the present invention
and fall within the spirit and scope of the present disclosure.
* * * * *