Acetabular shell having flared rim and fixation spikes

摘要

An acetabular component for an implantable hip joint prosthesis. An acetabular shell has an apex and a rim, and has a convex proximal surface for being received within a hemispherically reamed acetabulum in a press-fit relationship. The convex proximal surface is shaped as a surface of revolution defined by a curve segment rotated about an axis, where the curve segment and the axis lie in a common plane. The defining curve segment includes a first arc-segment and a second arc-segment. The first arc-segment has a center located on the axis, and the second arc-segment has a center offset from the axis. The convex proximal surface includes a first region defined by the first arc-segment in proximity to the apex and a second region defined by the second arc-segment in proximity to the rim. The convex proximal surface is diametrically oversized in the second region relative to the hemispherically reamed acetabulum. At least one bone-penetrating protrusion extends generally proximally from the convex proximal surface, but is limited in proximal extent to remain unengaged with the hemispherically reamed acetabulum at initial contact of the oversized second region with the hemispherically reamed acetabulum during implantation.