Pemberton's pericapsular osteotomy for the treatment of acetabular dysplasia.

We present the results of 80 Pemberton procedures carried out between 1977 and 1990. The patient age at the time of operation ranged between 2 and 12 years, and follow-up was between 1 and 15 years. Before Pemberton's operation, conservative treatment, closed and open reduction, and derotation femoral osteotomy were used. Pemberton's operation was combined with intertrochanteric femoral osteotomy in 30 cases. The mean values of the acetabular and center edge angle of Wiberg showed postoperative improvement of 19 and 17 degrees, respectively; whereas at follow-up, improvement was 20 and 23 degrees, respectively. Radiologically, 79% of the cases met Severin's classification grade I-II criteria. Clinically, 81% were classified as excellent and good. The results were closely correlated with ischemic necrosis due to preoperative treatment. Only patients belonging to groups II-IV of Kalamchi and MacEwen, plus one patient operated on at relatively old age (12 years), were found radiologically to be in Severin's groups III and IV. The results among patients operated on before age 7 were more favorable than those of patients operated on at an older age.