20-YEAR FOLLOW-UP OF BERNESE PERIACETABULAR OSTEOTOMY

Abstract

Since 1984, more than 1000 Bernese periacetabular osteotomies (PAO) have been performed for the treatment of developmental dysplasia of the hip (DDH) in adolescents and adults at the institution where this technique was developed. We present a concise 20-year follow-up of the first 75 PAOs whose initial and 10-year results had been published previously.

A retrospective study of the first 75 consecutive hips (63 patients) treated with PAO for DDH between April 1984 and December 1987 was performed. The mean patient age at surgery was 29.3 years ± 11.4 (13 – 56) and in 31% of all hips a previous surgical attempt to achieve sufficient coverage had been performed. Preoperatively, 58% of all hips presented with osteoarthritis and 49% with dysplasia Class 4 or higher according to Severin. Four patients (5 hips) were lost-to-follow-up and 1 patient (2 hips) died unrelated to surgery. The remaining 58 patients (68 hips) were followed for a mean of 20.4 years ± 1.1 (18.8 – 22.9) and 41 hips (60%) were preserved at last follow-up. Regarding the surviving hips with preoperatively no or slight osteoarthritis (52 hips), the survivor ship rate was 75%.

Twenty-seven hips were converted to a THA (26 hips) or hip arthrodesis (1 hip) which were defined as endpoints. The cumulative Kaplan-Meier survivorship at 20 years was 61%. The Cox regression analysis was performed to detect predictive factors for poor outcome and to calculate the corresponding hazard ratios. Six predictive factors for poor outcome were found: age over 30, a preoperative Merle d’Aubigné score less than 15, a positive preoperative anterior impingement test and limp, preoperative OA grade of more than 1, and a postoperative extrusion index of more than 20%.

Despite the fact that this series represented the learning curve of a technically demanding intervention of a very inhomogeneous patient group with various previous surgical attempts to achieve sufficient coverage and several concomitant intertrochanteric osteotomies, the 20-year results on the first 75 hips are promising.

Increased survivorship rates are expected for more recent series after identification of relative contraindications based on or analysis. PAO is an effective and successful surgical technique for correction of DDH.