An acetabular cup assembly includes a cup-like liner with a rim defining a first plane, an inner surface defining a hemispherical socket with a center of curvature close to the first plane and an outer frustoconical seating surface having a first taper and extending to the rim. The assembly also includes a sleeve having inner and outer frustoconical surfaces and a central axis and surrounding the liner. The inner surface of the sleeve has the same taper as the seating surface so that the sleeve wedges against said seating surface to fix the position of said center of curvature relative to the sleeve. The outer surface of the sleeve has a selected second taper which matches that of the seat surface of an acetabular cup shell in which the sleeve is seated. A method of revising an implanted acetabular cup assembly is also disclosed.