Radiographs of 84 hips with advanced or terminal stage osteoarhritis were evaluated after transtrochanteric vaigus osteotomy (TVO). Improvement of radiographical changes after osteotomy usually correlate with the clinical conditions of each osteoarhritis hip. The average age at operation was 44 (17-60) years old. Radiographical changes including joint space narrowing, osteosclerosis and cystic change were evaluated at 2 and 5 years after operation. Additionally, at the last time after operation (average 8.3 years (7-11)), they were evaluated comparing with those just before operation. Two years after operation, most hips whose acetabular head index (AHI) was more than 60% showed better radiographical appearances than before operation. The higher was the AHI of operated hips, the better the radiographical appearances remained for a longer time after operation. The radiographs of the hips after TVO with acetabuloplasty improved similarly to those of the hips whose AHI was more than 60%. These data show that the improvement of the radiographical sign of the operated hips depends on AHI, suggesting that the acetabular coverage of the head is an important factor when selecting operation methods. When AHI is low, acetabuloplasty should be carried out with TVO.
