gms | German Medical Science

Objective: The goal of the Periacetabular Osteotomy (PAO) is to correct the deficient acetabular coverage in hips with developmental dysplasia (DDH) to prevent secondary osteoarthritis. We present the 10-year survivorship, the clinical and radiographic outcome, and factors predicting poor outcome.

Methods: A retrospective study of 90 hips (83 patients) treated with PAO for DDH between January 1997 and January 2000 was performed. The mean age at surgery was 30±9.5 (11–49) years and the mean follow-up was 10.9±.9 (0.2–13.0) years. In all hips an arthrotomy was performed and in 33 of 90 hips (36.6%) an additional offset correction was necessary to allow impingement-free motion. Survivorship analysis was performed according to Kaplan and Meier and the endpoint was defined as a conversion to a total hip arthroplasty (THA). Demographical, clinical and radiological parameters were analyzed using the Cox regression analysis to detect predictive factors for poor outcome.

Results and conclusions: 11 hips were converted to a THA after 8.2±3.4 (1.3–12.3) years. This resulted in a cumulative Kaplan-Meier survivorship at 10 years of 91.6% (95%-confidence interval 85.6–96.6%). Age at operation and the preoperative osteoarthritis score according to Tönnis were significant predictors for poor outcome. At last follow up, the patients with preserved hip joints presented with a mean Merle d´Aubigné score of 15.8±2.4 (9–18).

The PAO is an effective and successful technique for the treatment of DDH to preserve or at least to decelerate the progression of secondary osteoarthritis. A good long term result depends on the preoperative cartilage condition and the age at surgery of the patient.