Twenty years' followup of intertrochanteric osteotomy for treatment of the dysplastic hip.

A followup study of more than 15 years of intertrochanteric osteotomy for osteoarthrosis of the dysplastic hip was performed in 52 hips of 42 patients with varus osteotomy and in 58 hips of 53 patients with valgus osteotomy. Varus osteotomy was indicated for predegenerative or early degenerative stages of osteoarthrosis, and valgus osteotomy was indicated for progressive or end stage disease. The average age at time of varus and valgus osteotomies was 25 and 37 years, respectively, and the average followup period was 21 and 20 years, respectively. Using Kaplan-Meier's method (end point, Harris Hip Score < 70 points or salvage operation), the 10- and 15-year survival rates for varus osteotomy were 89% and 87% and for valgus osteotomy were 66% and 38%, respectively. Radiographic measurements of the postoperative acetabular head index and center edge angle in varus osteotomy were better in the group with good results than those in the group with poor results. There were no differences in radiographic measurements between the group with good results and the group with poor results of valgus osteotomy. Intertrochanteric varus and valgus osteotomy delayed the need for total hip arthroplasty in young patients with osteoarthrosis of the dysplastic hip.