ACETABULAR CUP TAPER COVER AND LINER TRIAL

Abstract

An acetabular shell system. The shell system includes an acetabular shell having a convex outer portion and a concave inner portion. The shell system also includes a polymer sleeve having an outer portion sized and shaped to engage at least a portion of the concave inner portion of the acetabular shell.

Claims

1. An acetabular shell system comprising: an acetabular shell having a convex outer portion and a concave inner portion; and a polymer sleeve having an outer portion sized and shaped to engage at least a portion of the concave inner portion of the acetabular shell.

2. The shell system of claim 1, wherein the concave inner portion includes a locking mechanism and the polymer sleeve extends over the locking mechanism.

3. The shell system of claim 2, wherein the locking mechanism includes a female taper and the outer portion of the polymer sleeve includes a taper to engage the female taper.

4. The shell system of claim 2, wherein the locking mechanism includes a female taper and the outer portion of the polymer sleeve is cylindrical.

5. The shell system of claim 1, wherein, when the shell and sleeve are assembled, the sleeve including a rim which extends above of the inner portion of the shell.

6. The shell system of claim 1, wherein the sleeve includes a pull tab extending beyond the outer portion of the sleeve which engages the shell.

7. The shell system of claim 1, wherein the inner portion of the shell includes an apex and the sleeve includes an extension portion that extends toward the apex of the shell.

8. The shell system of claim 7, wherein the apex of the shell includes a screw hole and the extension portion of the sleeve extends around the screw hole.

9. The shell system of claim 7, wherein the extension portion of the sleeve includes a cap which extends over the apex of the shell.

10. A method for performing hip arthroplasty, the method comprising: inserting an acetabular shell into a prepared acetabulum, the acetabular shell having a taper and a sleeve covering the taper; inserting the head into the shell and sleeve; testing the range of motion of the head in the shell and sleeve; and removing the sleeve from the shell.

11. The method of claim 10, wherein the shell includes a locking portion and the sleeve extends over the locking portion.

12. The method of claim 10, wherein the sleeve includes an extension portion that extends towards an apex of the shell.

13. The method of claim 10, wherein the sleeve has the same thickness as a liner to be inserted into the shell.

Description

BRIEF DESCRIPTION OF FIGURES

[0020] FIG. 1 is a perspective view of an acetabular shell according to one embodiment of the present invention.

[0021] FIG. 2 is a perspective view of a sleeve according to one embodiment of the present invention.

[0022] FIG. 3 is a perspective view of the sleeve of FIG. 1 inserted into the acetabular shell of FIG. 1.

[0023] FIG. 4 is a perspective view of a sleeve and shell assembly according to another embodiment of the present invention.

[0024] FIG. 5 is a perspective view of a sleeve and shell assembly according to yet another embodiment of the present invention.

[0025] FIG. 6 is a perspective view of a sleeve and shell assembly according to yet another embodiment of the present invention.

[0026] FIG. 7 is a view of a trial liner and head of the prior art.

[0027] FIG. 8 is a flow chart illustrating the use of a sleeve according to one embodiment of the present invention.

DETAILED DESCRIPTION

[0028] An acetabular shell 10 according to one embodiment of the present invention is shown. As shown, the shell 10 includes a convex outer portion 12 and a concave inner portion 14. The convex outer portion 12 is inserted into a surgically prepared cavity in a patient's acetabulum during surgery. In this embodiment, the convex outer portion 12 includes a coating to enhance bone-ingrowth. In other embodiments, no coating may be included or other types of coatings or materials may be used. The concave inner portion 14 is designed to receive a liner (not shown) which will engage a head on a stem. The liner may be locked into the shell via a locking mechanism 15. In this embodiment, the locking mechanism includes a female taper 16 and a locking ring 18. Anti-rotation devices (ARDs) 20 are also included on the inner portion 14 of the shell.

[0029] Turning now to FIG. 2, an embodiment of a sleeve 22 according is illustrated. The sleeve is a polymer, such an ultrahigh molecular weight polyethylene, PEEK, or other polymer used in medical devices. The sleeve 22 includes an outer portion 24 and an inner portion 26. In this embodiment, the sleeve 22 is a single piece curved around with a single slit 28 between its two ends 30, 32.

[0030] The outer portion 24 engages the inner portion 14 of the shell 10 (FIG. 3) and extends over the locking mechanism 15 of the shell 10. The sleeve 22 protects the female taper 16 from debris and from becoming scratched. In some embodiments, the outer portion 24 of the sleeve 22 is tapered to match the taper of the inner portion 14 of the shell 10. In other embodiments, the outer portion 24 is cylindrical in shape and a portion of the outer portion 24 will rest against the tapered portion of the inner portion 14 of the shell 10. As shown in FIG. 3, when the sleeve 22 is inserted into the shell 10, a rim 34 of the sleeve 22 extends above a rim 36 of the shell 10. The rim 34 and portion 38 of the sleeve 22 that extend above the rim 36 of the shell 10 may allow a user to easily grasp the sleeve 22 in order to remove the sleeve 22 from the shell 10.

[0031] Turning now to FIG. 4, another embodiment of a sleeve 42 is illustrated. In this embodiment, the sleeve 42 includes most of the same features as the sleeve 22 illustrated in FIGS. 1-3. The sleeve 42 includes an outer portion 44 and an inner portion 46. The outer portion 44 engages the inner portion 14 of the shell 10. In this embodiment, the sleeve 42 is a single piece curved around with a pull tab 48 at one end. The pull tab 48 allows a user to easily grasp the sleeve 42 and remove it from the shell 10. As in the embodiment shown in FIGS. 1-3, the outer portion 44 may be tapered to match the taper of the inner portion 14 of the shell 10 or the outer portion 44 may be cylindrical.

[0032] FIG. 5 illustrates yet another embodiment of a sleeve 62. The sleeve 62 has an outer portion 64 and an inner portion 66. The outer portion 64 engages the inner portion 14 of the shell 10. The outer portion 64 may be tapered to match the taper of the inner portion 14 of the shell 10 or the outer portion 64 may be cylindrical.

[0033] The sleeve 62 includes two ends, 68, 70 that create a recess 72. The two ends 68, 70 extend inwardly via an extension portion 73 toward an apex 74 of the shell 10. The two ends 68, 70 are uniform and encircle a hole 76 in the apex 74. The extension portion 73 can act as a spacer so the sleeve 62 may also work as a trial liner. During surgery, when the shell 10 is implanted, a user may sometimes put a trial liner 100 in the shell 10 (FIG. 7). The shell 10 and trial liner 100 then engage the head 102 (FIG. 7) to check range of motion (as illustrated by arrows in FIG. 7). In the embodiment illustrated in FIG. 5, the extension portion 73 allows the user to trial off of the sleeve 62 without the need for a separate trial liner. The extension portion 73 has the same thickness as a liner, so the range of motion of the head can be adequately tested. This reduces inventory and makes the process simpler for the user.

[0034] FIG. 6 shows another embodiment of a sleeve 82. The sleeve 82 includes an outer portion 84 and an inner portion 86. The outer portion 84 engages the inner portion 14 of the shell 10. The outer portion 84 may be tapered to match the taper of the inner portion 14 of the shell 10 or the outer portion 84 may be cylindrical. In this embodiment, the sleeve 82 is a single piece that includes an extension portion 88 that extends toward the apex of the shell 10. In this embodiment, the extension portion 88 ends in a cap 90 that extends over the apex. The extension portion 84 may also be used as a trial liner as described above.

[0035] Turning now to FIG. 8, a method of how the sleeves as described above may be used. First, the acetabulum is prepared as is known in the art (step s110). This may be done by traditional reaming. Next, the shell 10 and the sleeve 22, 42, 62, or 82 are inserted into the prepared acetabulum (step s112). The sleeve 22, 42, 62, or 82 is covering the taper 16 of the shell 10. The user then may choose to trial off the shell 10 and sleeve 22, 42, 62, or 82 combination by inserting the head 100 and checking the range of motion at step s114. After the trial reduction is finished, the user removes the sleeve 22, 42, 62, or 82 at step s116, and the liner may be inserted (step s118). The user may choose to not trial off the sleeve 22, 42, 62, or 82 and may skip to step s116.

[0036] Although the present invention and its advantages have been described in detail, it should be understood that various changes, substitutions, and alterations can be made therein without departing from the spirit and scope of the present invention as defined by the appended claims.