Long-Term Hip Survivorship and Patient-Reported Outcomes of Periacetabular Osteotomy. The Washington University Experience

Background The Bernese periacetabular osteotomy (PAO) is a well-accepted acetabular reorientation procedure for the treatment of symptomatic acetabular dysplasia. There is limited data on the long-term outcomes of this procedure. In this study, we assessed the long-term hip survival and patient-reported outcomes of PAO used to treat symptomatic acetabular dysplasia. Methods We evaluated 127 hips at an average of 16 years postoperatively with a minimum follow-up of 13 years; 109 hips completed the follow-up. Hips were evaluated using a modified Harris hip score (mHHS) and Western Ontario and McMaster Universities Osteoarthritis Index (WOMAC) pain subscale score. A WOMAC pain score of >=10 and/or mHHS of <=70 were considered to indicate a clinically symptomatic hip. The Kaplan-Meier analysis assessed survivorship with an endpoint of total hip arthroplasty (THA). Results Of the 109 hips that completed follow-up, 16.5% (n=18) underwent THA at an average of 13.5 years (range: 1.4 – 20.6 years), 2.8 % (n=3) hips underwent revision PAO at an average of 3.4 years, and 0.9 % (n=1) underwent revision hip arthroscopy at 1.8 years. A total of 87 hips (79.8%) were free of revision and/or THA with a mean mHHS of 85.1 ± 16.6 and a mean WOMAC pain score of 2.9 ± 4.8 at the 15 year follow-up. Of the 87 hips that did not undergo THA or revision, 19.5 % (n=17) were symptomatic based on a WOMAC pain score>=10 and/or mHHS <=70. Kaplan-Meier analysis revealed a survival rate without conversion to THA of 97.1 % (95% confidence interval [CI]: 91.5%, 99.1%) at 10 years, 93.3% (95% CI: 86.4%, 96.8%) at 15 years, and 71.5 % (95% CI: 60.0%, 83.7%) at 20 years postoperatively. Conclusion This study demonstrates that patients with symptomatic acetabular dysplasia can be treated effectively with the Bernese periacetabular osteotomy. Marked improvement in hip pain and function can be achieved for most patients and the 20-year survivorship is over 70%. A third of patients undergoing a PAO clinically failed for pain or function. Only half of these patients required conversion to Total hip arthroplasty occurring, on average, over 10 years after PAO.