POLYETHYLENE WEAR IN THE CHARNLEY OFFSET BORE ACETABULAR CUP A RADIOLOGICAL ANALYSIS

We studied wear in the ultra-high-molecular-weightpolyethylene offset bore socket in 54 hips which had had Charnley low-friction arthroplasty. At an average follow-up of 8.1 years, the mean penetration rate was 0.04 mm per year. Correlation between the depth of socket penetration and the incidence of socket migration was confirmed, but socket migration occurred with lower penetration than had been previously reported. J Bone Joint Surg [Br] 1996;78-B:82-4. Wear of ultra-high-molecular-weight polyethylene (UHMWPE) sockets is of major concern for the long-term survival of total hip arthroplasty (THA). It is debatable whether the problem is mainly mechanical (Wroblewski 1985) or biological (Schmalzried et al 1992). For the Charn-ley low-friction arthroplasty (LFA) the reported averag