Evaluation of the design and clinical performance of cementless acetabular components.

Three hundred four cementless acetabular components: 54 Ceramic (Richards Medical Co, Memphis, TN); 33 T-Tap (Richards Medical Co); 22 MHP, (Biomet Inc, Warsaw, IN); 109 PCA (Howmedica, Rutherford, NJ), and 86 S-ROM SuperCup (Joint Medical Products Co, Stamford, CT) were implanted in 271 patients between October 1982 and June 1986. Two hundred forty-one hips had good to excellent Harris hip scores, although a significant difference was found when the scores of patients with conical threaded cups were compared with those of patients who had hemispheric porous ingrowth cups and the SuperCup. Also, patients with conical threaded cups had a greater incidence of groin and buttock pain (P less than .01) and underwent more revision procedures (P less than .01). Our clinical and radiographic review indicates that all cementless acetabular cups are not equal and the hemispheric porous cups and hemispheric porous cups with peripheral threads are far superior to conical threaded cups.