Prosthetic knee with posterior stabilized femoral component
AssigneeIntermedics Orthopedics, Inc.
InventorsThomas B. Buford, III, Charles H. Perrone, Jr., Jeffery C. Higgins
Life of this patent
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Abstract
A posterior stabilized knee prosthesis with removable pin in the femoral component. The removable pin has a tapered split ring lock which prevents the pin from backing out. A split ring is provided on the pin which rides in a groove on the pin. When the pin is properly seated, the split ring engages a corresponding groove within the femoral prosthesis, locking the pin in place. Chamfers are provided on both the front and back of the split ring so that the split ring will compress as the pin is being screwed into the femoral component and also so that the pin can be removed if necessary.
Claims16
A femoral knee prosthesis for use selectively as a cruciate retaining prosthesis or a posterior stabilized prosthesis, said prosthesis having medial and lateral condyle parts, a transverse shaft adapted to be selectively installed between the condyle parts, said parts having a bore therein for selectively receiving said transverse shaft, said bore having securing means in at least one of said parts for securing said shaft in said bore,
- a circumferential groove on said shaft,
- a corresponding groove in said bore, which corresponding groove will lie adjacent said groove on said shaft when said shaft is properly inserted in said bore,
- a split ring carried in one of said grooves, said ring being capable of being displaced substantially entirely within said one of said grooves but normally extending radially out of said one of said grooves, said ring having two opposed chamfers, said chamfers being normally exposed out of said one of said grooves,
- whereby said split ring is displaced within said one of said grooves as said shaft is inserted into said bore until the other of said grooves is adjacent said one of said grooves and whereby said split ring is also displaced within said one of said grooves to withdraw said shaft from said bore.
An implantable prosthesis comprising a first part for affixation to a first bone of a patient, a second part for affixation to a second bone of a patient, and a hinge apparatus connecting said first and second parts, said apparatus comprising
- a bore in at least one of said first or second parts, said bore being at least partially threaded, and
- a shaft of biologically compatible material adapted to be secured in said bore, said shaft having
- a threaded section on said shaft, adapted to threadingly engage said threaded bore,
- a circumferential groove on said shaft,
- a corresponding groove in said bore, which corresponding groove will lie adjacent said groove on said shaft when said shaft is properly inserted in said bore,
- a split ring carried in one of said grooves, said ring being capable of being displaced substantially entirely within said one of said grooves but normally extending radially out of said one of said grooves, said ring having two opposed chamfers, said chamfers being normally exposed out of said one of said grooves,
- whereby said split ring is displaced within said one of said grooves as said shaft is inserted into said bore until the other of said grooves is adjacent said one of said grooves and whereby said split ring is also displaced within said one of said grooves to withdraw said shaft from said bore.
Dependencies are inferred from the claim text.