Mid- to Long-Term Outcome of Cementless Total Hip Arthroplasty in Younger Patients

PURPOSE: To assess mid- to long-term outcomes of cementless primary total hip arthroplasty (THA) in younger patients. METHODS: Records of 28 women and 34 men (75 hips) aged 18 to 55 (mean, 38) years who underwent primary THA using a hydroxyapatite-coated stem and a threaded cup and had been followed up for a mean of 10 (6-15) years were reviewed. 13 of the patients had bilateral THAs. Clinical and radiographic outcomes were evaluated. RESULTS: After a minimum follow-up of 7 (range, 7-14) years, 12 (16%) of the hips were revised, of which 8 (11%) were for the cup. The causes for revision were late deep infections (n=2), aseptic loosening of the cup (n=4), and polyethylene wear (n=6). No stem was revised for aseptic loosening. Osteolysis was noted in 24 (38%) hips. Of the 63 unrevised hips, the mean Harris Hip Score was 92 (range, 45-100) and the mean D'Aubigne and Postel score was 17 (range, 9-18). The survival of the threaded cup was 88% at 10 years, using revision surgery as the end point. 27 (41%) of the hips showed signs of polyethylene wear; 15 were >2 mm. CONCLUSION: In younger patients undergoing THA, rates of polyethylene wear and pelvic osteolysis are high, and thus long-term follow-up is crucial.