Enhanced fixation system for a prosthetic implant

摘要

A system is disclosed for the fixation of a component of an artificial joint for replacing a damaged natural joint. A cup-shaped socket member is formed with a plurality of radially directed through bores, each being threaded adjacent an outer hemispherical surface and each being tapered adjacent an inner hemispherical surface to define a seating surface. A fastener with an elongated shank secures the socket member to a bone and is received through each through bore. The fastener extends between a head at a first end and a tip at a second end. Mounting threads on the shank intermediate the first and second ends are threadedly engaged with the threads in the through bore and a tapered outer surface extending between the mounting threads and the second end is matingly engaged with the seating surface in the bore. The shank between the mounting threads and the tip end may be smooth, or porous coated to encourage bone ingrowth fixation, or have cancellous threads thereon for threaded engagement with the bone, or different combinations of these expedients may be used.