Granulomatous reaction and cystic bony destruction associated with high wear rate in a total knee prosthesis.

This is a case report of a Cloutier total knee arthroplasty that was removed from an obese, large, 66-year-old man three years after implantation because of aseptic loosening. At surgery there was a thickened black synovium and black cystic areas in the exposed bone. The articulating surfaces of the tibial component, which is made from Poly Two (a carbon polyethylene composite), were grossly abraded, and the supporting metal tray was broken in two. The femoral component showed signs of abnormal wear at the places where it was articulating with the displaced tibial component. The tissues showed a granulomatous reaction with marrow fibrosis and cystic destruction of bone. It is postulated that aseptic loosening was accelerated by a granulomatous response to overload, abrasion, and local dissemination of particles.