FEMORAL HEADS, MOBILE INSERTS, ACETABULAR COMPONENTS, AND MODULAR JUNCTIONS FOR ORTHOPEDIC IMPLANTS, AND METHODS OF USING FEMORAL HEADS, MOBILE INSERTS, ACETABULAR COMPONENTS, AND MODULAR JUNCTIONS FOR ORTHOPEDIC IMPLANTS

摘要

PROBLEM TO BE SOLVED: To provide prosthetic femoral heads, mobile inserts, and acetabular components capable of alleviating soft tissue impingement, reducing implant wear, and reducing frictional torque; and to provide modular junctions capable of minimizing the incidence of loosening and micromotion that can occur at the modular junctions.SOLUTION: A femoral head implant includes a peripheral portion of an outer surface that is contoured so as to achieve an inward shift of the outer surface relative to an overall spherical geometry. The inward shift is achieved through a change in radius of curvature, the radius of curvature being one or more convex radii. The inward shift is axisymmetric around a femoral head axis 74 of the femoral head implant and occurs at an angle greater than about 80° and less than about 115°. The inward shift is at least about 1 mm at a location of maximum inward shift. The contoured geometry minimizes overhang of the femoral head 64 beyond the native articular surface, and thereby minimizing potential for soft-tissue impingement.SELECTED DRAWING: Figure 11B