IP Library Granted Patent US 6,913,623
Granted Patent B1
US 6,913,623 · App. 09/638,789 · Granted Jul 5, 2005

Two piecefused femoral hip stem

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Quick Facts
Patent No.
US 6,913,623
App. No.
09/638,789
Granted
Jul 5, 2005
Kind
B1
Abstract

An orthopedic implant includes a metal core having a first end, a second end, a first elastic modulus, and a first porosity. A proximal body is fused directly onto the metal core between the first and second ends. The proximal body has a second elastic modulus, which is less than the first elastic modulus, and a second porosity, which is greater than the first porosity. The porosity of the proximal body may vary throughout.

Claims (38)

1. An orthopedic implant comprising:

a metal core having a first proximal end and a distal send end defining an outer surface, the metal core having a first elastic modulus; and

a proximal body that is configured to fit in at least a resected proximal end of a femur fused on the metal core between the first proximal end and the second distal end, a portion of said metal core extending beyond a distal end of said proximal body thereby exposing said outer surface of said portion of said metal core extending beyond said proximal body, the body having a second elastic modulus which is less than the first elastic modulus, wherein the proximal body has a variable thickness that tapers outwardly away from the outer surface toward the first proximal end.

2. The implant as defined in claim 1 wherein the metal core has a contoured longitudinal axis.

3. The implant as defined in claim 1 wherein the proximal body has a smooth external surface.

4. The implant as defined in claim 3 wherein the proximal body has a completely porous structure.

5. The implant as defined in claim 4 wherein the proximal body is formed of metallic powder.

6. An orthopedic implant comprising:

a metal core having an outer surface and a first end and a second end, the metal core having a first porosity; and

a porous proximal body that is configured to fit in at least a resected proximal end of a femur fused on the metal core between the first end and the second end, a portion of said metal core extending beyond a distal end of said proximal body thereby exposing said outer surface of said portion of said metal core extending beyond said proximal body, the proximal body having a second porosity which is greater than the first porosity, wherein the proximal body extends from a proximal end to a distal end, and the proximal body tapers outwardly and away from the outer surface from the distal end to the proximal end.

7. The implant as defined in claim 6 wherein the proximal body has a variable thickness, with a first thickness at the proximal end and a second thickness at the distal end.

8. The implant as defined in claim 7 wherein the first thickness is greater than the second thickness.

9. The implant as defined in claim 8 wherein the proximal body has a conical shape.

10. The implant as defined in claim 9 wherein the proximal body has a completely porous structure.

11. The implant as defined in claim 6 wherein the porosity of the proximal body various throughout.

12. A method of fabricating an orthopedic implant comprising the steps of:

providing a metal core with a first end and a second end, the metal core having a first elastic modulus;

placing a mold around the metal core, the mold having a first end, a second end, and an interconnecting passage formed therethrough, the passage extending from the first end of the mold to the second end of the mold;

filling the mold with material for creating a proximal body;

removing the mold, leaving a shaped proximal body on the metal core, the proximal body extends outwardly from a surface of the metal core and ha a cross section with a varying thickness and conical shape; and

sintering the metal core and the proximal body, whereby the proximal body is fused onto the metal core.

13. The method as defined in claim 12 wherein the step of placing a mold around the metal core includes the step of inserting the metal core through the passage thereby having the first end of the metal core extend from the first end of the mold, and the second end of the metal core extend from the second end of the mold.

14. The method as defined in claim 12 wherein the step of filling the mold includes filling the mold with material for creating a porous proximal body.

15. The method as defined in claim 12 wherein the step of filling the mold includes filling the mold with material for creating a proximal body with a second elastic modulus which is less than the first elastic modulus of the metal core.

16. The method as defined in claim 12 wherein the step of placing a mold includes the step of placing a mold having a smooth inner surface.

17. The method as defined in claim 12 wherein the step of placing a mold includes the step of placing a mold having a porous inner surface.

18. A method of fabricating an orthopedic implant comprising the steps of:

providing a metal core with a first end and a second end, the metal core having a first porosity;

filling a multi-piece mold with material for creating a proximal body having a second porosity, the second porosity being greater than the first porosity;

joining the multi-piece mold to form a complete mold around the metal core;

removing the mold, leaving a shaped proximal body on the metal core, the proximal body extends outwardly from a surface of the metal core and has a cross section with a varying thickness and conical shape; and

sintering the metal core and the proximal body, whereby the proximal body is fused onto the metal core.

19. A method of fabricating an orthopedic hip implant comprising the steps of:

providing an elongated metal core with a first end and a second end;

providing a mold;

sintering a porous proximal body in the mold while being separated from the metal core; and

fusing the proximal body onto the metal core between the first end and the second end after the step of sintering the porous proximal body in the mold.

20. The method as defined in claim 19 wherein the step of fusing the proximal body onto the metal core further includes the step of brazing the proximal body to the metal core.

Assignments (6)
CHANGE OF NAME Recorded Apr 10, 2006
From: ZIMMER AUSTIN, INC.
To: ZIMMER, INC.
Reel/Frame 017435/0714 →
CHANGE OF NAME Recorded May 17, 2005
From: CENTERPULSE ORTHOPEDICS INC.
To: ZIMMER AUSTIN, INC.
Reel/Frame 016263/0264 →
PATENT RELEASE AGREEMENT Recorded Nov 5, 2003
From: UBS AG, STAMFORD BRANCH
To: CENTERPULSE USA INC.
Reel/Frame 014699/0404 →
CHANGE OF NAME Recorded Nov 26, 2002
From: SULZER ORTHOPEDICS INC.
To: CENTERPULSE ORTHOPEDICS INC.
Reel/Frame 013515/0637 →
SECURITY INTEREST Recorded Nov 20, 2002
From: CENTERPULSE ORTHOPEDICS INC.; CENTERPULSE USA HOLDING CO., CORPORATION, DELAWARE; CENTERPULSE USA INC., CORPORATION, DELAWARE; SULZER CARBOMEDICS INC., CORPORATION, DELAWARE; CENTERPULSE DENTAL INC., CORPORATION, DELAWARE; CENERPULSE SPINE-TECH INC., CORPORATION, DELAWARE; CENTERPULSE ORTHOPEDICTS LTD., LIMITED LIABILITY COMPANY, SWITZERLAND; CENTERPULSE LTD., LIMITED LIABILITY COMPANY, SWITZERLAND
To: UBS AG, STAMFORD BRANCH AS SECURITY AGENT FOR THE SECURED PARTIES
Reel/Frame 013467/0328 →
ASSIGNMENT OF ASSIGNOR'S INTEREST Recorded Aug 15, 2000
From: ZHU, MENGKE
To: SULZER ORTHOPEDICS INC.
Reel/Frame 011022/0478 →