Modular tibial implant

• US 7,771,484 B2
• Filed: 02/28/2006
• Issued: 08/10/2010
• Est. Priority Date: 02/28/2006
• Status: Active Grant

• Current Assignee: Howmedica Osteonics Corp. (Stryker Corporation)
• Original Assignee: Howmedica Osteonics Corp. (Stryker Corporation)
• Inventors: Campbell, Michael N.
• Primary Examiner(s): Matthews; William H.
• Assistant Examiner(s): Woznicki; Jacqueline
• Application Number:
  US11/364,700
• Publication Number:
  US 20070203582A1
• Time in Patent Office: 1,624 Days
• Field of Search: 623 2032- 2034
• US Class Current: 623/20.34
• CPC Class Codes: A61F 2/389 Tibial components A61F2/3868 takes precedence
• CPC Class Codes: A61F 2002/30136 undulated or wavy, e.g. serpentine-shaped or zigzag-shaped
• CPC Class Codes: A61F 2002/30604 modular
• CPC Class Codes: A61F 2002/30884 Fins or wings, e.g. longitudinal wings for preventing rotation within the bone cavity
• CPC Class Codes: A61F 2230/0004 Rounded shapes, e.g. with rounded corners

Abstract

A modular tibial implant includes a tibial baseplate having a top surface, a bottom surface, and first and second openings extending between the top and bottom surfaces, and a bone engaging element having a distal end, a proximal end, and a longitudinal axis extending between the distal and proximal ends, the proximal end of the bone engaging element having a threaded opening alignable with the first opening of the tibial baseplate and a post insertible into the second opening of the tibial baseplate. The implant include a threaded fastener insertible into the aligned first opening and threaded opening, wherein the threaded fastener is rotatable for securing the proximal end of the bone engaging element to the bottom surface of the tibial baseplate, and a cam element insertible into the second opening of the tibial baseplate for engaging the post. The cam element is rotatable for moving the baseplate relative to the bone engaging element along an axis that traverses the longitudinal axis of the bone engaging element.

Claims

1. A modular tibial implant comprising:

a tibial baseplate having a top surface and a bottom surface and first and second through openings extending between the top and bottom surfaces;

a bone engaging stem element mountable on the baseplate and having a distal end, a proximal end, and a longitudinal axis extending between the distal and proximal ends, the proximal end having a post extending proximally into the second through opening;

a fastener engageable with said tibial baseplate and said bone engaging element for securing said tibial baseplate and said bone engaging stem element together, the fastener extending through the first through opening in the baseplate; and

a cam element separate from said fastener and being engageable with a wall surrounding said second through opening in said tibial baseplate and the cam element having a bore for receiving said post on said bone engaging stem element for moving said baseplate relative to said bone engaging stem element along an axis that traverses the longitudinal axis of said bone engaging stem element.

2. The implant as claimed in claim 1, further comprising:

the proximal end of said bone engaging stem element having a threaded opening aligned with the first through opening of said tibial baseplate, and the post at least partially inserted into the second through opening of said tibial baseplate;

said fastener being a threaded fastener inserted into the aligned first through opening and threaded opening, wherein said threaded fastener is rotatable for securing said bone engaging stem element and said tibial baseplate together; and

said cam element being inserted into the second through opening of said tibial baseplate for engaging the post, wherein said cam element is rotatably adjustable for moving said baseplate relative to said bone engaging stem element.

3. The implant as claimed in claim 1, wherein said cam element bore has an asymmetrical surface that engages the post located at the proximal end of said bone engaging stem element.

4. The implant as claimed in claim 1, wherein said post has a cross-section that is elongated along an axis.

5. The implant as claimed in claim 1, wherein said tibial baseplate has a periphery and a pin opening extending between the periphery and the second through opening of said tibial baseplate.

6. The implant as claimed in claim 5, wherein the pin opening is in communication with the second through opening of said tibial baseplate.

7. The implant as claimed in claim 6, further comprising a pin insertable into the pin opening for engaging said cam element after said cam element is inserted into the first through opening of said tibial baseplate and on to the post.

8. The implant as claimed in claim 7, wherein said cam element has a groove formed in an outer surface thereof and the pin engages the groove for limiting movement of said cam element.

9. The implant as claimed in claim 7, wherein said cam element has a groove formed in an outer surface thereof and the pin engages the groove for limiting rotation of said cam element.

10. The implant as claimed in claim 1, wherein said cam element bore has an opening having an asymmetrical surface that engages an outer surface of the post at the proximal end of said bone engaging element for moving said tibial baseplate relative to said bone engaging stem element when said cam element is rotated in a direction perpendicular to the longitudinal axis.

11. The implant as claimed in claim 1, wherein said bone engaging element is a keel or a stem.