[Intertrochanteric rotational osteotomies in idiopathic femur head necrosis--comparison of different procedures].

PROBLEM

The aim of this study was to to compare different intertrochanteric osteotomies for avascular necrosis of the hip 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 total of 63 flexion osteotomies (partly combined with varisation or valgisation), 29 rotational osteotomies, 13 varisation osteotomies, 8 medializing osteotomies and 2 extension osteotomies were performed. The mean follow-up period for all osteotomies was 69 months (13-180 months).

RESULTS

At the time of follow-up investigation, already 75.9% of patients with a rotational osteotomy had received a total hip arthroplasty, comparing to only 34.9% following flexion osteotomy. The Harris Hip Score of the remaining 7 rotational osteotomies was 86.5, for the 41 flexion 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 correlation between the size of the necrotic area (radiographic ap + axial necrotic sector) and the risk of failure can be demonstrated. Sugioka's rotational osteotomy showed only a very low probability of survival after 5 years (15.9%), in contrast to the flexion osteotomy (5a: 71.6%, 10a: 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 intertrochanteric osteotomies for avascular necrosis of the hip has to be discussed critically today. Good results can only be expected with small necrotic areas using the flexion osteotomy. It was impossible to obtain satisfactory long-term results with the rotational osteotomy due to a high risk of complications.