Midterm results of transtrochanteric anterior rotational osteotomy combined with shelf acetabuloplasty for osteonecrosis with acetabular dysplasia: A preliminary report

Background Transtrochanteric anterior rotational osteotomy for osteonecrosis of the femoral head should be performed to obtain [34% of the ratio of transposed intact posterior articular surface to the acetabular weight-bearing area. Therefore, the presence of acetabular dysplasia is unfavorable in obtaining this ratio. Between 1999 and 2005, we performed the modified Spitzy shelf acetabuloplasty combined with anterior rotational osteotomy for three patients (four hips) with acetabular dysplasia. In this study, we retrospectively evaluated the midterm results of this combined surgery. Methods and results Patients comprised one man and two women with a mean age of 29 years at the time of surgery. Mean follow-up was 7.5 years. The average preoperative Harris hip score of 65.5 points increased to an average of 79.3 points at the latest follow-up. None of the hips required conversion to total hip arthroplasty during the follow-up periods. The average postoperative intact ratio without a shelf procedure was 23%, and with a shelf procedure, this ratio increased to be 58%. As a result, collapse progression was not observed in any of the four hips. Conclusions Our results suggest that anterior rotational osteotomy combined with shelf acetabuloplasty may be a surgical option for osteonecrosis of the femoral head with acetabular dysplasia. Further studies with a larger patient population are necessary to clarify appropriate indications and limitations of this combined surgery.