Composite prosthesis
AssigneeJohnson & Johnson Orthopaedics, Inc.
InventorsJohn V. Hamilton, Salvatore Caldarise, Debra J. Treacy
Life of this patent
Estimating the term…
Abstract
A composite stem for a prosthesis, particularly a hip prosthesis, including a metal core and a fiber reinforced composite shell surrounding the core to provide modulus values that are similar to bone. The composite shell is preferably composed of braided fibers and a thermoplastic resin. The stiffness of the prosthesis can be varied along the length of the stem. The metal core contributing between 5 and 25 percent of the total flexural stiffness of the stem.
Claims14
A load bearing orthopaedic prosthesis comprising a stem having a distal end adapted to be inserted into a cavity formed in a bone and a proximal end opposed to the distal end;
- said stem comprising an inner metal core extending substantially the length of the stem from the proximal end to the distal end of the prosthesis;
- a composite shell comprising braided high strength fibers bonded with a thermoplastic resin surrounding said metal core along substantially the entire length thereof;
- said metal core contributing between 5 and 25% of the total flexural stiffness of the stem at any position along the length of the stem.
A load bearing orthopaedic prosthesis comprising a stem having a distal end adapted to be inserted into a cavity formed in a bone and a proximal end opposed to the distal end;
- said stem comprising an inner metal core extending substantially the length of the stem from the proximal end to the distal end of the prosthesis;
- a composite shell comprising high strength fibers bonded with a thermoplastic resin surrounding said metal core along substantially the entire length thereof;
- said composite shell comprising between 40 and 75 weight percent fiber and 25 to 60 weight percent resin;
- said metal core contributing between 5 and 25% of the total flexural stiffness of the stem at any position along the length of the stem.
A load bearing orthopaedic prosthesis comprising a stem having a distal end adapted to be inserted into a cavity formed in a bone and a proximal end opposed to the distal end;
- said stem comprising an inner metal core extending substantially the length of the stem from the proximal end to the distal end of the prosthesis;
- a composite braided shell comprising a high strength fiber bonded with a thermoplastic resin surrounding the metal core;
- an insert located at the proximal end of the prosthesis and disposed between the metal core and the composite shell;
- said metal core contributing between 5 and 25% of the total flexural stiffness of the stem at any position along the length of the stem.
Dependencies are inferred from the claim text.