Abstract
Purpose: The effect of cemented total hip arthroplasty (THA) stem surface finish and geometry on clinical outcomes is controversial. This is the first report of results from a multi-center study evaluating a cemented, polished, triple-tapered prosthesis.
Methods: Two-hundred-seventeen C-Stems (DePuy, Warsaw, IN, USA) were implanted consecutively at three centers. Hips with 2-year minimum A-P radiographs receiving prospective clinical and independent retrospective radiographic examinations were included. Seven patients (9 hips) died and two had early revisions (one trauma-induced loosening; one due to poor cement technique). Of 206 hips remaining, 162 reached minimum follow-up. Cement-mantle grade, subsidence, stem-cement radiolucency, femoral osteolysis, and Harris Hip Score (HHS) were recorded annually.
Results: Mean age was 70 years (range 39–100). Of the 162 patients evaluated, 103 were female and 59 male. There were 17 deaths (20 hips) after minimum follow-up. Mean radiographic follow-up was 4 years (range: 2–6). At last follow-up, the mean HHS was 88 (range: 44–100). Cement-mantle grades were: A(27%), B(49%), C1(6%), C2(14%) and undetermined(4%). No stem subsidence greater than 2mm was observed. Debonding more than 1mm was noted in 6 hips (4%), including one cement fracture. Of 3 hips (2%) with femoral osteolysis, two instances were exclusively in proximal zones.
Conclusions: Excellent to good results were obtained in this multi-center, cemented, triple-tapered THA stem series. Radiographic results were similar to published results from other successful stems sharing these features. Further research is warranted to determine whether long-term results compare favorably to others designed to resist subsidence and loosening.
Correspondence should be addressed to: Orah Naor, IOA Secretary and Co-ordinator (email: ioanaor@netvision.net.il)
