Fragmentation of methylmethacrylate: a cause of late failure of total hip replacement. A case report.

Extensive localized bone lysis in the femur following implantation of a metal-on-metal total hip prosthesis was observed. Fragmentation of the cement occurred 10 years after implantation. Histologic and ultrastructural features of macrophages are consistent with the hypothesis that particles from the acrylic resin were the factors stimulating the macrophagic reaction. Both mechanical factors and changes of the physico-chemical properties of the cement may have an etiologic role.