ABSTRACT
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).
Subject(s)
Arthroplasty, Replacement, Hip/instrumentation , Coated Materials, Biocompatible/chemistry , Durapatite/chemistry , Hip Prosthesis , Titanium/chemistry , Acetabulum/surgery , Arthroplasty, Replacement, Hip/methods , Equipment Failure Analysis , Female , Humans , Male , Middle Aged , Prospective Studies , Prosthesis Design , Prosthesis Failure , Surface PropertiesABSTRACT
Femoral component revisions with extensively coated stems have shown promising clinical results, although concerns over stress shielding still exist. We retrospectively reviewed 59 patients undergoing femoral component revision with an extensively hydroxyapatite (HA)-coated stem. The average length of follow-up was 3.3 years (range, 2-5 years). The average preoperative Harris Hip Score was 43 points, which improved to 86 points at the latest follow-up (P < .01). The overall mechanical failure rate was 2%. No evidence of stress shielding was seen in 78% of patients. The clinical results of this series using an extensively HA-coated stem are similar to those using an extensively porous-coated stem. Long-term follow-up is required to determine if an extensively HA-coated implant will be superior to an extensively porous-coated implant with regard to stress shielding.
