Hip joint prosthesis

• US 3,938,198 A
• Filed: 09/27/1973
• Issued: 02/17/1976
• Est. Priority Date: 08/04/1970
• Status: Expired due to Term

• Current Assignee: Cutter Laboratories, Inc. (Bayer AG)
• Original Assignee: Cutter Laboratories, Inc. (Bayer AG)
• Inventors: Kahn, Paul, Stubstad, James A.
• Primary Examiner(s): Frinks, Ronald L.
• Application Number:
  US05/401,506
• Time in Patent Office: 873 Days
• Field of Search: 3/1, 3/1.9-1.913, 128/92 C, 128/92 CA, 128/92 R, 128/92 D, 128/DIG. 21
• US Class Current: 623/22.15
• CPC Class Codes: A61F 2/30767 Special external or bone-contacting surface, e.g. coating for improving bone ingrowth
• CPC Class Codes: A61F 2/30907 Nets or sleeves applied to surface of prostheses or in cement
• CPC Class Codes: A61F 2/30965 Reinforcing the prosthesis by embedding particles or fibres during moulding or dipping
• CPC Class Codes: A61F 2/3662 Femoral shafts
• CPC Class Codes: A61F 2002/3007 Coating or prosthesis-covering structure made of elastic material, e.g. of elastomer
• CPC Class Codes: A61F 2002/30448 using adhesives
• CPC Class Codes: A61F 2002/30461 sutured, ligatured or stitched
• CPC Class Codes: A61F 2002/30563 having elastic means or damping means, different from springs, e.g. including an elastomeric core or shock absorbers
• CPC Class Codes: A61F 2002/30906 shot- sand- or grit-blasted
• CPC Class Codes: A61F 2002/3092 having an open-celled or open-pored structure
• 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 2002/3448 Multiple cups made of three or more concentric shells fitted or nested into one another
• CPC Class Codes: A61F 2002/3631 with an integral complete or partial peripheral collar or bearing shoulder at its base
• CPC Class Codes: A61F 2220/005 using adhesives
• CPC Class Codes: A61F 2220/0075 sutured, ligatured or stitched, retained or tied with a rope, string, thread, wire or cable
• CPC Class Codes: A61L 27/04 Metals or alloys
• CPC Class Codes: A61L 27/34 Macromolecular materials
• CPC Class Codes: A61L 27/56 Porous materials, e.g. foams or sponges
• CPC Class Codes: C08L 67/02 Polyesters derived from dicarboxylic acids and dihydroxy compounds C08L67/06 takes precedence

Abstract

A prosthesis for replacement of a damaged joint or load-bearing structure in an animal or human body comprises a shaped structural member, a relatively thick or cushioning coating of a physiologically inert elastomer over the surfaces of the structural member in load-bearing relationship with the skeletal structure of the body, and an open-pore, tissue-ingrowth-receptive fabric coating the elastomer, all elements being firmly bonded to each other. In many embodiments, a stem of the prosthesis comprising the above elements is adapted to be inserted into a bone cavity, and is eventually affixed firmly thereto by fibrous tissue and bony ingrowth. Stability of the stem portion is enhanced by buttresses integral with the base of the stem.

Claims

1. A hip prosthesis for repairing a damaged hip joint in an animal skeletal structure, comprising in combination:

I. an acetabulum prosthesis having

a. a hemispherical metal cup having an exterior annular flange at its base, a concave surface and a convex surface,

b. a relatively thick cushioning layer of an elastomer disposed over and covering said convex face and said flange,

c. an open pore, physiologically inert coating of fabric disposed over and covering said elastomer, and adapted to receive host tissue ingrowth,

d. said cup, said elastomer and said coating all being firmly bonded to each other, and

Ii. a femoral head prosthesis having a ball at one end, said ball fitting in said cup.

2. The prosthesis of claim 1 wherein the concave surface of the metal cup has affixed to it a polymeric surface adapted to receive and coact with said femoral head.

3. The prosthesis of claim 2 wherein said polymeric surface'"'"'s annular flange lies beyond the arc of the hemisphere and has an annular exterior recess, and a metal band in said recess retaining said ball in said cup.

4. The prosthesis of claim 3 wherein said metal cup has a radial flange extending around said cup, for securing pins for temporary anchoring to bone structure.

5. A hip prosthesis for repairing a damaged hip joint in an animal skeletal structure, comprising in combination:

I. an acetabulum prosthesis having

a. a hemispherical metal cup having an exterior annular flange at its base, a concave surface and a convex surface,

b. a relatively thick cushioning layer of an elastomer disposed over and covering said convex face and said flange,

c. an open pore, physiologically inert coating of fabric disposed over and covering said elastomer, and adapted to receive host tissue ingrowth, and

d. said cup, said elastomer and said coating all being firmly bonded to each other, and

Ii. a femoral head prosthesis having a ball at one end, said ball fitting in said cup, said femoral head prosthesis comprising

a. a stem adapted to be inserted into a medullary canal of a bone of said structure,

b. a reinforcing core extending into said stem,

c. a cushioning coating of elastomer over said core, secured to and at least partially enclosing the same, and

d. a surface covering of open-pore material secured to said elastomer and adapted to receive host tissue ingrowth.

6. A femoral head prosthesis, including in combination:

a. a rigid ball member,

b. a rigid stem core member extending from said ball member and integral therewith,

c. a cushioning coating of elastomer secured to and at least partially enclosing said stem core member, and

d. a surface layer of fibrous material capable of receiving tissue ingrowth secured to at least a portion of said elastomer.