Fixation of a ceramic structural member by way of gliding in a femoral part

• US 6,214,051 B1
• Filed: 01/16/1998
• Issued: 04/10/2001
• Est. Priority Date: 01/17/1997
• Status: Expired due to Fees

• Current Assignee: Ceramtec AG Innovative Ceramic Engineering (Albemarle Corporation)
• Original Assignee: Ceramtec AG Innovative Ceramic Engineering (Albemarle Corporation)
• Inventors: Pfaff, Hans-Georg, Kälberer, Hartmut, Badorf, Dirk
• Primary Examiner(s): Milano, Michael J.
• Assistant Examiner(s): STEWART, ALVIN J
• Application Number:
  US09/008,427
• Time in Patent Office: 1,180 Days
• Field of Search: 623/20, 623/18, 623/21, 623/16
• US Class Current: 623/20.14
• CPC Class Codes: A61F 2/30767 Special external or bone-contacting surface, e.g. coating for improving bone ingrowth
• CPC Class Codes: A61F 2/3859 Femoral components
• CPC Class Codes: A61F 2002/30383 made by laterally inserting a protrusion, e.g. a rib into a complementarily-shaped groove
• CPC Class Codes: A61F 2002/30385 the rib and groove having non-parallel, e.g. conically-tapered, cooperating sides, e.g. having a trapezoidal front cross-section
• CPC Class Codes: A61F 2002/30433 using additional screws, bolts, dowels, rivets or washers e.g. connecting screws
• CPC Class Codes: A61F 2002/30451 soldered or brazed or welded
• CPC Class Codes: A61F 2002/30774 internally-threaded
• CPC Class Codes: A61F 2002/3079 Stepped or enlarged apertures, e.g. having discrete diameter changes
• CPC Class Codes: A61F 2002/30929 having at least two superposed coatings
• CPC Class Codes: A61F 2220/0025 Connections or couplings between prosthetic parts, e.g. between modular parts; Connecting elements
• CPC Class Codes: A61F 2220/0041 using additional screws, bolts, dowels or rivets, e.g. connecting screws
• CPC Class Codes: A61F 2220/0058 soldered or brazed or welded
• CPC Class Codes: A61F 2310/00011 Metals or alloys
• CPC Class Codes: A61F 2310/00179 Ceramics or ceramic-like structures
• CPC Class Codes: A61F 2310/00604 Coating made of aluminium oxide or hydroxides

Abstract

A knee-joint endoprosthesis includes a metallic femoral part (2) anchored in the femur that articulates with a tibial part anchored in the tibia bone, the articulating surface of the femoral part (2) being a ceramic structural member (3) that is connected to the femoral part (2) in a mechanically stable manner.

The attachment of the ceramic structural member (3) to the femoral part (2), can be accomplished by using a conical clamping device, by use of a fixing screw, by shrinking, soldering or welding it on, or by vapor deposition or spray application.

Claims

1. Knee-joint endoprosthesis comprising a metallic femoral part anchored in the femur that articulates with a tibial part anchored in the tibia bone, the articulating surface of the femoral part being a ceramic structural member that is connected to the femoral part in a mechanically stable manner, wherein the ceramic structural member is anchored on the femoral part by means of a conical clamping device which extends over the entire region of the articulating surface wherein the conical clamping device comprises a conical slot in the femoral part, and conical lateral surfaces on the ceramic structural member, the conical slot having tapering lateral surfaces such that the conical slot becomes wider at an outside of the slot and narrower at an interior of the slot, and the conical lateral surfaces of the structural member being inserted in the conical slot.

2. Knee-joint endoprosthesis according to claim 1, wherein the angle of the conical clamping device amounts to between 5°

and 20°

.

3. Knee-joint endoprosthesis according to claim 1, wherein two structural members are used per knee-joint endoprosthesis.

4. Knee-joint endoprosthesis according to claim 1, wherein femoral part has a median part a branched end, and wherein the ceramic structural member extends to an end of the median part opposite the branched end.