ACETABULAR CUP BODY PROSTHESIS

摘要

An acetabular cup prosthesis (86) has a cup body with correspondingly shaped inner concave and outer convex (87) surfaces. The cup body has an apex (98) as well as a base (91) that defines a plane (92). The cup body outer convex surface (87) has a portion (89) between the rim (103) and a distance about one third of the distance from the rim (103) to the apex (98), which portion (89) has an outer surface formed by first generating an arc (106) between the rim (103) and a transition point (90) about one third of the distance from the rim (103) to the apex (98), arc having a radius of curvature (101) whose origin (102) is near to, but not coincident with the center of the base (91), and then rotating the arc 360 degrees about a central axis (99) of the cup body, which axis runs between the apex (98) and the center of the base. In another embodiment, a plurality of cup bodies (86) are provided in a range of sizes between about 40 mm and 80 mm. Each cup body (86) has a companion rotary reamer (111) that is correspondingly shaped. The companion cup body (86) is oversized between about 1 mm and 3 mm relative to the companion rotary reame r (111), so that a generally constant change in volume is provided for all cup sizes between 40 mm and 80 mm.