Evolution of aggressive granulomatous periprosthetic lesions in cemented hip arthroplasties.

The authors analyzed the histologic findings from material retrieved during 17 revision operations from 15 patients who had cemented total hip arthroplasty or hemiarthroplasty. In 13 patients, the indication for revision was aseptic loosening. In four patients, technical error during implantation of the prostheses made revision necessary. The histologic pictures in the loosened and nonloosened prostheses were similar, characterized by the presence of a synovial-like membrane at the site corresponding to the hip joint cavity or abutting the implant, underneath which were found aggregates of histiocytes and foreign-body giant cells within a dense fibrous matrix. The main foreign material in all patients consisted of fine granules or larger cement particles. A few polyethylene fibers were also observed in some patients. Metal deposits were found in three patients with titanium alloy implants and extensive loosening. The most interesting aspect of this series was the opportunity it provided to study the progressive development of the synovial-like membrane and the first appearance of the cement granulomas in non-loosened cases. The first signs of the synovial membrane appeared 2.5 months postoperatively, whereas the first cement debris were observed as early as seven months after the implantation of the prosthesis. The hip joint newly formed membrane in the nonloosened cases did not differ histologically from that in the loosened cases. Because the histology of loosened and technically poorly placed nonloosened-prostheses are the same, the authors believe that the mechanism of failure associated with cell macrophage-mediated osteolysis may be the same.