Deposition of calcium pyrophosphate in tissue after revision arthroplasty of the hip

We reviewed histologically the incidence and pathogenesis of the deposition of calcium pyrophosphate dihydrate (CPPD) crystals in the pseudocapsule, f emoral and acetabular membranes and periprosthetic tissue at revision of 78 9 cases of failed total hip replacement. In 13, periprosthetic tissues were found to have deposits of CPPD crystals in areas of cartilaginous metaplas ia; four also showed evidence of localised deposition of amyloid, None of t he patients had a history of chondrocalcinosis in the hip or other joints. Cartilaginous metaplasia and other changes in periprosthetic tissues may pr edispose to the deposition of CPPD and associated localised amyloid.