The histomorphologic and morphometric study of asymptomatic hip arthroplasty. A postmortem study.

The purpose of this study was to determine the histologic findings at the bone-cement interface in successful asymptomatic total hip replacements (THR) retrieved from patients at autopsy. The criteria for a successful hip arthroplasty were clinical, radiologic, and direct examination of the prosthesis at the time of harvesting. Twelve patients with a total of 14 cemented hip arthroplasties came to autopsy at a mean of 4.7 years after implantation. A detailed histomorphometric objective means of assessing the tissue response was applied to the membrane. The density of histiocytes correlated with the thickness of the membrane, the density of polyethylene particles, and the time after implantation. The fibrohistiocytic membrane in this group of patients was similar to that described in the literature in cases of loose THRs. These findings advance current understanding of transcellular particle transportation (directional exocytosis) in tissue reactions to endoprostheses of THR.