INTERTROCHANTERIC OSTEOTOMIES IN IDIOPATH IC AVASCULAR NECROSIS OF THE FEMORAL-HEAD - A COMPARISON OF DIFFERENT METHODS

Problem: The aim of this study was to to compare different intertrocha nteric osteotomies for avascular necrosis of the hrp and to discuss it in the light of improving results of total hip arthroplasty. Method: 106 patients with diagnosis of avascular necrosis of the hip underwent an intertrochanteric osteotomy. During an interval of 14 years a tota l of 63 flexion osteotomies !partly combined with varisation or valgis ation), 29 rotational osteotomies, 13 varisation osteotomies, 8 medial izing osteotomies and 2 extension osteotomies were performed. The mean follow-up period for all osteotomies was 69 months (13-180 months). R esults: At the time of follow-up investigation, already 75,9% of patie nts with a rotational osteotomy had received a total hip arthroplasty, comparing to only 34,9% following flexion osteotomy. The Harris Hip S core of the remaining 7 rotational osteotomies was 86,5, for the 41 fl exion osteotomies the HHS rated 73,8 points. A high incidence of early complications (55,2%) was seen after rotational osteotomies, compared to 17,5% after flexion osteotomy. For all osteotomies a high correlat ion between the size of the necrotic area (radiographic ap + axial nec rotic sector) and the risk of failure can be demonstrated. Sugioka's r otational osteotomy showed only a very low probability of survival aft er 5 years (15,9%), in contrast to the flexion osteotomy (5a: 71,6%, 1 0a.: 49,6%). The subgroup of flexion osteotomy with a necrotic sector < 180 degrees achieves the best survival probability of 89,2% after 5 years and 60,7% after 10 years. Conclusion: The indication for intertr ochanteric osteotomies for avascular necrosis of the hip has to be dis cussed critically today. Good results can only be expected with small necrotic areas using the flexion osteotomy. It was impossible to obtai n satisfactory long-term results with the rotational osteotomy due to a high risk of complications.