Reactive pelvic cyst following total hip arthroplasty. A case report.

A 77-year-old woman presented with an intrapelvic cyst which had developed secondary to polyethylene wear of the socket after total hip arthroplasty. This reactive cyst surrounded polymethylmethacrylate cement fragments due to excessive penetration in the pelvis during the initial procedure 20 years previously. This pelvic mass was responsible for gynaecologic symptoms. The cyst was resected in a first stage. Revision hip arthroplasty is scheduled because of cup wear and progressive femoral osteolysis. Cement extrusion must be avoided during total hip arthroplasty to prevent pelvic complications, since these problems can present even several years later. Cement intrusion into the pelvis possibly opens up a pathway for polyethylene wear particles to migrate into the pelvis.