A prosthetic joint has a head member with a load-bearing surface, and a
bearing member with a concave bearing surface oriented and configured
such that during articulation of the prosthetic joint the load-bearing
surface engages the concave bearing surface along an annular intermediate
surface portion located between first and second ends of the bearing
member and spaced from each of the first and second ends. The
configuration of the bearing surface provides clearance between the head
member and the bearing surface along portions of the bearing surface
lying between the annular intermediate surface portion and each end of
the bearing member to assure engagement of the load-bearing surface at
the annular intermediate surface portion. An opening passes through the
bearing member at the first end of the bearing member and communicates
with the concave bearing surface.