The relative safety of polymethylmethacrylate. A controlled clinical study of randomly selected patients treated with Charnley and ring total hip replacements.

Forty patients from a group of seventy elected to participate in a prospective randomized clinical study designed to evaluate the systemic effects of polymethylmethacrylate implanted with a Charnley total hip replacement, utilizing patients treated with a Ring total hip prosthesis ad controls. Intraoperative alterations in cardiovascular function were related to use of methylmethacrylate, but postoperative changes in pulmonary function, erythrocyte sedimentation rate, serum lactic acid dehydrogenase, serum glutamicoxalacetic transaminase, and alkaline phosphatase were not. Charnley total hip replacements were associated with more ectopic-bone formation twelve months postoperatively. The two "latent" infections recognized during the thirty-four months of the study were in hips without acrylic fixation.