Hydroxylapatite-coated acetabular shells with arc deposited titanium surface roughening and dual radius design

A retrospective review of two multicenter prospective stud- ies was performed of a dual radius design acetabular shell, one with a titanium arc deposited surface roughening and hydroxylapatite coating (AD HA) designed to optimize initial component stability and enhance biological ixation and the other grit-blasted and HA (GB HA) coated. The purpose of the study was to evaluate intermediate clinical and radiographic success of this device, as compared to a grit-blasted HA (GB HA) coated shell of the same design. Eighty-nine hips (83 patients) with a diagnosis of noninlam- matory degenerative joint disease (NIDJD) were implanted with the AD HA shells (Group 1) by three surgeons at three sites. Patients were evaluated clinically and radiographi- cally for 5 to 8 years postoperatively (mean, 5.5 years). Clinical and radiographic data for 179 cases with GB HA shells and a diagnosis of NIDJD (Group 2) were reviewed retrospectively at an equivalent time frame. Fifty-eight hips in each group with a minimum 5-year follow-up were identiied through patient matching, based on age, gender, and preoperative body mass index, to provide the cohorts for this study. Radiographically, all patients in Group 1 were stable, and there were no cases of acetabular loosening or revision of the acetabular shell. Three patients in Group 2 had radiographic evidence of acetabular shell migration and eight shells (three dislocations, ive acetabular loosenings) had been revised by 60 months postoperatively. Intermediate results with the AD HA shells are encouraging, as evidenced by clinical success, radiographic stability, and 100% survi- vorship at 5 to 8 years (mean, 66 months).