IMPLANT SLEEVE FOR CEMENT HIP STEMS

• US 20130018482A1
• Filed: 07/12/2011
• Published: 01/17/2013
• Est. Priority Date: 07/12/2011
• Status: Active Grant

• Current Assignee: Biomet Manufacturing, LLC (Zimmer Biomet Holdings, Inc.)
• Original Assignee: Biomet Manufacturing, LLC (Zimmer Biomet Holdings, Inc.)
• Inventors: Meridew, Jason D., White, John R., Bollinger, Mark A.
• Granted Patent: US 8,585,770 B2
• Time in Patent Office: Days
• US Class Current: 623/23.46
• CPC Class Codes: A61F 2/30724 Spacers for centering an implant in a bone cavity, e.g. in a cement-receiving cavity
• CPC Class Codes: A61F 2/30734 Modular inserts, sleeves or augments, e.g. placed on proximal part of stem for fixation purposes or wedges for bridging a bone defect
• CPC Class Codes: A61F 2/36 Femoral heads ; Femoral endoprostheses
• CPC Class Codes: A61F 2/3662 Femoral shafts
• CPC Class Codes: A61F 2/4603 for insertion or extraction of endoprosthetic joints or of accessories thereof
• CPC Class Codes: A61F 2002/30235 tubular, e.g. sleeves
• CPC Class Codes: A61F 2002/30507 using a threaded locking member, e.g. a locking screw or a set screw
• CPC Class Codes: A61F 2002/30574 with an integral complete or partial collar or flange
• CPC Class Codes: A61F 2002/30579 with mechanically expandable devices, e.g. fixation devices
• CPC Class Codes: A61F 2002/30909 Nets
• CPC Class Codes: A61F 2002/4615 of spacers

Abstract

An implant sleeve operable to center an implant at an implantation site. The implant sleeve includes a proximal end, a distal end, an annular sidewall, a mesh portion of the annular sidewall, and an interior area. The annular sidewall is between the proximal end and the distal end. The mesh portion defines a plurality of openings in the annular sidewall. The interior area is defined by the annular sidewall and is configured to receive a stem of the implant. A longitudinal axis of the implant sleeve extends along an axial center of the interior area. In response to force applied to the implant sleeve, the implant sleeve compresses and the mesh portion expands outward from the longitudinal axis.

Claims

1. An implant sleeve operable to center an implant at an implantation site, the implant sleeve comprising:

a first end;

a second end;

a shaped outer sidewall between the first end and the second end;

a mesh portion of the outer sidewall that defines a plurality of openings in the outer sidewall; and

an interior area encompassed by the outer sidewall and configured to receive a stem of the implant, a longitudinal axis of the implant sleeve extends along an axial center of the interior area;

wherein in response to force applied to the implant sleeve, the implant sleeve compresses and the mesh portion expands outward from the longitudinal axis.

2. The implant sleeve of claim 1, wherein the sleeve compresses and the mesh portion expands outward from the longitudinal axis in response to force applied to the implant sleeve along the longitudinal axis to one of the first end or the second end.

3. The implant sleeve of claim 1, wherein the outer sidewall is tapered from the first end to the second end, the first end is a proximal end and the second end is a distal end.

4. The implant sleeve of claim 1, wherein the outer sidewall includes an intermediate sidewall portion between the first end and the second end, the intermediate sidewall portion is substantially solid;

wherein the mesh portion includes a first mesh portion between the intermediate sidewall portion and the first end, and a second mesh portion between the intermediate sidewall portion and the second end;

wherein in response to force applied to the proximal end parallel to the longitudinal axis, the intermediate sidewall portion moves along the longitudinal axis and remains at a generally constant distance from the longitudinal axis; and

wherein the first end is a proximal end and the second end is a distal end of the implant sleeve.

5. The implant sleeve of claim 1, wherein the openings include slots extending in a distal to proximal direction.

6. The implant sleeve of claim 1, wherein the outer sidewall includes a distal sidewall portion at the second end that defines a threaded aperture configured to receive a threaded fastening device.

7. The implant sleeve of claim 1, wherein the implant sleeve is formed entirely of a metal.

8. The implant sleeve of claim 1, wherein the stem of the implant is a stem of a femoral implant that includes a compression rod configured to compress the implant sleeve from the second end, which is a distal end proximate to a distal tip of the implant.

9. The implant sleeve of claim 1, further comprising a solid interior sidewall that is between the outer sidewall and the longitudinal axis, the outer sidewall is compressible and expandable independent of the interior sidewall.

10. An implant sleeve operable to center an implant at an implantation site, the implant sleeve comprising:

a rigid first end portion at a first end of the implant sleeve;

an annular sidewall extending from the rigid first end portion to a second end of the implant sleeve, the annular sidewall defining an interior area of the implant sleeve that is configured to receive a stem of the implant;

a rigid second end portion at the second end of the implant sleeve;

an aperture defined by one of the rigid first end portion and the rigid second end portion that is configured to receive a fastener there through to secure the implant sleeve to the stem; and

a mesh portion forming a portion of the annular sidewall between the rigid first end portion and the rigid second end portion, the mesh portion expands outward from a longitudinal axis of the interior area in response to a compression force applied to one of the rigid first end portion or the rigid second end portion.

11. The implant sleeve of claim 10, wherein the mesh portion expands outward from the longitudinal axis in response to a compression force applied along the longitudinal axis to a rigid annular flange at the rigid first end portion.

12. The implant sleeve of claim 10, wherein the interior area is tapered from the rigid first end portion to the rigid second end portion.

13. The implant sleeve of claim 10, wherein the rigid first end portion and the rigid second end portion remain at a constant distance from the longitudinal axis as the implant sleeve is compressed in response to the compression force.

14. The implant sleeve of claim 10, wherein the implant sleeve is formed entirely of a metal.

15. The implant sleeve of claim 10, wherein the implantation site includes an intramedullary canal of a femur and the implant includes a femoral implant configured to be secured in the intramedullary canal.

16. A method for centering a stem of an implant at an implantation site comprising:

implanting at the implantation site the implant having a sleeve rigidly mounted to the stem of the implant, the stem extends through an interior area of the sleeve; and

compressing the sleeve by applying force to the sleeve to expand a mesh portion of the sleeve outward from the stem and into engagement with sidewalls of the implantation site to thereby center the stem at the implantation site.

17. The method of claim 16, further comprising implanting the implant in an intramedullary canal of a femur;

and

forming a bone cement mantle around the stem and the sleeve, the cement mantle is reinforced by the sleeve.

18. The method of claim 16, further comprising compressing the implant with a compression tool including a handle and a semi-circular shaft with a distal portion, the distal portion has a size and shape that corresponds to a proximal surface of an annular flange of the sleeve.

19. The method of claim 16, further comprising securing the sleeve to the stem with a fastener extending through a sidewall portion of the sleeve.

20. The method of claim 16, further comprising compressing the sleeve by applying force to one of a proximal end of the sleeve or a distal end of the sleeve.