Acetabular cup

• US 5,879,398 A
• Filed: 02/14/1995
• Issued: 03/09/1999
• Est. Priority Date: 02/14/1995
• Status: Expired due to Term

• Current Assignee: Zimmer Technology Incorporated (Zimmer Biomet Holdings, Inc.)
• Original Assignee: Zimmer Incorporated (Zimmer Biomet Holdings, Inc.)
• Inventors: Lin, Steve T., Krebs, Steven L., Devanathan, Thirumalai, Rohr, William L. Jr., Schoenle, Paul D., Swarts, Dale F.
• Primary Examiner(s): Yu, Mickey
• Assistant Examiner(s): SNOW, BRUCE EDWARD
• Application Number:
  US08/388,089
• Time in Patent Office: 1,484 Days
• Field of Search: 623/22, 623/16, 623/18
• US Class Current: 623/22.21
• CPC Class Codes: A61F 2/30907 Nets or sleeves applied to surface of prostheses or in cement
• CPC Class Codes: A61F 2/3094 Designing or manufacturing processes
• CPC Class Codes: A61F 2/30965 Reinforcing the prosthesis by embedding particles or fibres during moulding or dipping
• CPC Class Codes: A61F 2/34 Acetabular cups
• CPC Class Codes: A61F 2002/30324 differing in thickness
• CPC Class Codes: A61F 2002/30616 Sets comprising a plurality of prosthetic parts of different sizes or orientations
• CPC Class Codes: A61F 2002/30968 Sintering
• CPC Class Codes: A61F 2002/3429 with an integral peripheral collar or flange, e.g. oriented away from the shell centre line
• CPC Class Codes: A61F 2250/0036 differing in thickness
• CPC Class Codes: A61F 2310/00395 Coating or prosthesis-covering structure made of metals or of alloys

Abstract

The present invention is directed to an acetabular cup prosthesis for implantation into a pelvic bone. A cup having a cavity for receiving a femoral head is formed of a polymeric material having a predetermined tensile strength. A backing is disposed about and attached to the polymeric cup. The backing has a porous construction defining interstitial pores, with the pores being sized to receive a portion of the polymeric cup therein and adapted for allowing ingrowth of the bone therein. The portion of the polymeric cup received within the pores results in an interface strength between the polymeric cup and the backing which is substantially equal to the tensile strength of the polymeric material.

Claims

1. A first and second acetabular cup prosthesis, each of said first and second acetabular cups having a different outside diameter at a rim thereof, each of said first acetabular cup and said second acetabular cup comprising:

a polymeric cup having a cavity for receiving a femoral head; and

a backing disposed about and attached to said polymeric cup, said backing having a thickness and further having a porous construction defining interstitial pores, said polymeric cup being attached to said backing by penetrating into said pores a predetermined penetration depth;

at least one of said backing thickness and said penetration depth varying between said first acetabular cup and said second acetabular cup, whereby each of said first acetabular cup and said second acetabular cup have substantially the same stiffness in a radial direction.