Proximal femoral bone loss and increased rate of fracture with a proximally hydroxyapatite-coated femoral component

We performed a retrospective analysis of the clinical and radiological outc omes of total hip replacement using an uncemented femoral component proxima lly coated with hydroxyapatite, Of 136 patients, 118 who had undergone 124 primary total hip replacements were available for study, Their mean age was 66.5 years (19 to 90) and the mean follow-up was 5.6 years (4.25 to 7.25), At the final follow-up the mean Harris hip score was 92 (47.7 to 100), Per iprosthetic femoral fractures, which occurred in seven patients (5.6%), wer e treated by osteosynthesis in six and conservatively in one. We had to rev ise five femoral components, one because of aseptic loosening, one because of septic loosening and three because of periprosthetic fracture, At the fi nal follow-up there were definite signs of aseptic loosening in two patient s. Radiologically, proximal femoral bone loss in Gruen zones I and VI was evid ent in 96.8% of hips, while bone hypertrophy in zones III and V was seen in 64.7%, In 24 hips (20.2%) the mean subsidence of the stem was 3.7 mm which occurred within the first 12 postoperative weeks. This indicated poor init ial stability, which might have been aggravated by early weight-bearing, Th e high rate of failure in our study suggests that proximal femoral bone los s affects the long-term survival of the replacement.