Prosthesis for cemented fixation and method for making the prosthesis

• US 8,715,359 B2
• Filed: 10/14/2010
• Issued: 05/06/2014
• Est. Priority Date: 10/30/2009
• Status: Active Grant

• Current Assignee: Depuy Ireland Unlimited Company (Johnson & Johnson)
• Original Assignee: Depuy (Johnson & Johnson)
• Inventors: Deffenbaugh, Daren L, Zannis, Anthony D
• Primary Examiner(s): STEWART, ALVIN J
• Application Number:
  US12/904,643
• Publication Number:
  US 20110106268A1
• Time in Patent Office: 1,300 Days
• Field of Search: 623/20.29, 623/20.32, 623 2034- 2036, 623/22.4, 623/23.15, 623/23.29, 623/23.3, 623/23.36, 623 235- 2354, 623/16.11, 623/18.11, 623/20.14, 623/20.17
• US Class Current: 623/20.29
• CPC Class Codes: A61B 17/14 Surgical saws A61B17/1637 takes precedence; tooth saws A61C3/12 ; Accessories therefor
• CPC Class Codes: A61F 2/3836 Special connection between upper and lower leg, e.g. constrained
• CPC Class Codes: A61F 2/389 Tibial components A61F2/3868 takes precedence
• CPC Class Codes: A61F 2/4202 for ankles
• CPC Class Codes: A61F 2002/30321 differing in roughness
• CPC Class Codes: A61F 2002/30878 with non-sharp protrusions, for instance contacting the bone for anchoring, e.g. keels, pegs, pins, posts, shanks, stems, struts
• CPC Class Codes: A61F 2002/3092 having an open-celled or open-pored structure
• CPC Class Codes: A61F 2002/30957 using a positive or a negative model, e.g. moulds
• CPC Class Codes: A61F 2002/30967 Diffusion bonding
• CPC Class Codes: A61F 2002/4619 for extraction
• CPC Class Codes: A61F 2250/0025 differing in roughness
• CPC Class Codes: A61F 2310/00023 Titanium or titanium-based alloys, e.g. Ti-Ni alloys

Abstract

A joint prosthesis system is suitable for cemented fixation. The system has two metal implant components and a bearing. One of the metal implant components has an articulation surface for articulation with the bearing. The other metal implant component has a mounting surface for supporting the bearing. One of the metal implant components includes an extension, such as a stem or pegs, with an exposed outer surface. The metal implant component from which the extension extends comprises titanium and the exposed outer surface of the extension comprises a different form of titanium. A method of making the joint prosthesis is also disclosed.

Claims

1. A joint prosthesis comprising:

a first metal component having a solid metal portion with a solid metal articulation surface and a second solid metal surface opposite the solid metal articulation surface, the first metal component further having a porous metal portion along the second solid metal surface, the porous metal portion including a bone-engaging surface opposite from the second solid metal surface;

a bearing having an articulation surface shaped to bear against the articulation surface of the first metal component and an opposite surface;

a second metal component having a solid metal portion with a solid metal mounting surface and a second solid metal surface opposite the solid metal mounting surface, the second metal component further having a porous metal portion along the second solid metal surface, the porous metal portion including a bone-engaging surface opposite from the second solid metal surface; and

an extension extending beyond the bone-engaging surface of one of the porous metal portions of one of the metal components to an exposed end, the extension having an opposite end received in a recess in the second solid metal surface of the solid metal portion of one of the metal components, an exposed outer surface and a length from the opposite end to the exposed end;

wherein;

the extension is configured for stabilizing the metal component when implanted in a bone of a patient;

the length of the extension from the bone-engaging surface to the exposed end consists of titanium foam having a void space of at least 65% by volume;

the solid metal portion of the metal component from which the extension extends comprises a titanium alloy; and

the titanium foam of the extension comprises commercially pure titanium.

2. The joint prosthesis of claim 1 wherein the exposed outer surface of the extension at the exposed end of the extension has a different roughness than at least a part of the exposed outer surface of the extension between the exposed end and the opposite end.

3. The joint prosthesis of claim 1 wherein the extension is selected from the group consisting of a peg and a stem.

4. The joint prosthesis of claim 1 wherein the porous metal portions of the metal components comprise commercially pure titanium.

5. The joint prosthesis of claim 1 wherein:

the prosthesis is an ankle prosthesis;

the first metal component comprises a distal tibial component; and

the extension extends out from the bone-engaging surface of the distal tibial component.

6. The joint prosthesis of claim 1 wherein:

the prosthesis is a knee prosthesis;

the first metal component is a distal femoral component configured to replace the distal end of the femur; and

the second metal component is a tibial tray configured to replace the proximal end of the tibia.

7. The joint prosthesis of claim 6 wherein:

the extension extends outward from and is bonded to the solid titanium alloy of the tibial tray by sintering.

8. The joint prosthesis of claim 7 wherein the bone-engaging surface of the tibial tray comprises commercially pure titanium foam bonded to the solid titanium alloy of the tibial tray by sintering.

9. The joint prosthesis of claim 6 wherein:

the articulating surface of the femoral component comprises solid titanium alloy, the solid titanium alloy extending from the articulating surface toward the bone-engaging surface; and

the extension is bonded to the solid titanium alloy of the femoral component by sintering.

10. The joint prosthesis of claim 9 wherein the bone-engaging surface of the femoral component comprises commercially pure titanium foam bonded to the solid titanium alloy of the femoral component by sintering.