Alumina ceramic bearings for total hip arthroplasty: five-year results of a prospective randomized study.

UNLABELLED: Three hundred twenty-eight ceramic bearings were implanted by six surgeons in 316 patients as a part of a prospective randomized US Investigational Device Exemption study comparing alumina ceramic bearings with cobalt chrome-on-polyethylene bearings. There was no difference between the control metal-on-polyethylene and the alumina bearing couple patient cohorts regarding demographics or clinical scores through 7 years. Revision for any reason occurred in 2.7% of the patients with alumina bearings and 7.5% of the control patients with polyethylene bearings. Osteolysis was found in 1.4% of the patients with alumina bearings and in 14.0% of the control patients. At an average followup of 5.0 years (range, 1-86 months) no ceramic fractures or ceramic bearing failures have occurred. Results of this study suggest that alumina ceramics perform as well as the metal-on-polyethylene in clinical scores, but the patients with ceramic bearings had fewer revisions and less osteolysis. These results lead us to think that this new alumina ceramic bearing provides a safe option for younger and more active patients.

LEVEL OF EVIDENCE: Therapeutic study, Level I-1b (randomized controlled trial, no significant difference, but narrow confidence intervals). See the Guidelines for Authors for a complete description of levels of evidence.