Wear-reducing geometry of articulations in total joint replacements
AssigneeScyon Orthopaedics AG
InventorSlobodan Tepic
Life of this patent
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Abstract
The invention reduces wear in total joint articulations by modifications of the shape of either component of the kinematic pair, so as to result in an annular surface contact between the two components. Fluid trapped between the two components within the inner contour of the annular contact area is pressurized under load due to elastic deformation of the components and exuded out through inter-articular gap over the surface of contact, aiding in lubrication and reducing the wear. Reduced to practice for a total hip joint with UHMWPE-metal pair, the wear rate tested in a hip joint simulator up to five million cycles was reduced by factor seven to fifteen compared to conventionally shaped components.
Claims14
1-26. (canceled)
A total hip joint prosthesis articulation wherein the concave (101;
- 201) and the convex (102;
- 202) components of the articulation are partially congruent over an annular surface area (121;
- 221) in the unloaded state.
A total joint prosthesis articulation wherein the concave and the convex components of the articulation are partially congruent over an annular area of contact in the unloaded state.
A total joint prosthesis articulation wherein the concave and the convex components of the articulation form an annular area of contact in the unloaded state and under a tare-load.
A total joint prosthesis articulation wherein the concave and the convex components of the articulation form an interrupted annular area of contact in the unloaded state and under a tare-load and a closed annular contact under physiological loads.
A total joint prosthesis articulation according to 35, comprising one of a total hip prosthesis, a total spinal disk prosthesis, a total knee prosthesis, a total prosthesis for a single knee/tibia condyle, a total shoulder prosthesis, a total finger prosthesis, a total elbow prosthesis, a total wrist prosthesis, and a total ankle prosthesis.
Dependencies are inferred from the claim text.