DEGA ACETABULOPLASTY COMBINED WITH INTERTROCHANTERIC OSTEOTOMIES - LONG-TERM RESULTS

Between 1973 and 1984, 70 modified Dega acetabuloplasties done simulta neously with intertrochanteric osteotomies in 51 patients with develop mental dysplasia of the hip were reviewed for long-term results and an alyzed for causes of failure, Mean patient age at operation was 2.9 ye ars (range, 8 months-8 years), and mean followup time was 15.2 years ( range, 10-19 years). Topical investigations were based on clinical cri teria of the Severin classification and radiologic criteria of the Com mission for the Study of Hip Dysplasia of the German Society of Orthop aedics and Traumatology, The review of clinical documents and investig ations showed very good and good results in 80% of the hips, The Trend elenburg sign was a useful clinical indicator for problematic cases, M easurements on radiographs were classified into deviation grades from the normal range. Values of the acetabulum and the acetabulum to head relation were normal or slightly abnormal in >80% of hips. Measurement s of the femoral head and neck were in the low normal range, The lowes t percentage of normal values was in 24 cases with coxa valga after ac etabuloplasty combined with derotational varus osteotomy. Poor clinica l and radiologic outcome usually was the result of avascular necrosis of the femoral head or recurring valgus deformity after derotational v arus osteotomy, The rate of avascular necrosis as a consequence of the operation was 5.7%, The risk of avascular necrosis caused by derotati onal varus osteotomy is lower than the risk of later development of de formities in the proximal femur.