Long-term results of intertrochanteric varus osteotomy for arthrosis of the dysplastic hip (over 10 years' follow-up).

We performed a retrospective clinical and radiographic review of the long-term results of 64 hips in 53 patients who underwent intertrochanteric varus osteotomy for arthrosis of the hip at the pre- or early stage with acetabular dysplasia. Their average age at operation was 26 years. The average duration of follow-up was 18 years and 10 months. The mean Harris hip score was 77 +/- 9 points pre-operatively, and improved significantly to 84 +/- 13 points at the final follow-up. The acetabular coverage influenced the final outcome, and the postoperative prognosis was predictable from the acetabular head index (AHI) on a pre-operatively done hip maximum abduction radiograph (abd XP). We conclude that varus osteotomy for a dysplastic hip should be considered when the acetabular coverage is sufficient, and that a good prognosis can be expected when AHI on abd XP is greater than 60%.