Periacetabular Osteotomy for Symptomatic Acetabular Dysplasia in Patients ≥40 Years Old: Intermediate and Long-Term Outcomes and Predictors of Failure

Abstract

Background: The Bernese periacetabular osteotomy (PAO) is controversial as a treatment for symptomatic acetabular dysplasia in patients ≥40 years of age. We conducted a retrospective study to evaluate the outcomes, measure the survival rate, and identify factors associated with PAO failure in patients ≥40 years of age.

Methods: We performed a retrospective study of patients ≥40 years of age undergoing PAO. Study eligibility criteria were met by 166 patients (149 women; mean age, 44 ± 3 years), and 145 (87%) were followed for ≥4 years after PAO. We used a Kaplan-Meier curve with right-censoring to calculate survivorship, with "failure" defined as either conversion to or recommendation for total hip arthroplasty or a Western Ontario and McMaster Universities Osteoarthritis Index (WOMAC) pain score of ≥10 at the most recent follow-up. We used simple logistic regression models to determine whether any preoperative characteristics were significantly associated with PAO failure.

Results: The median follow-up time was 9.6 years (range, 4.2 to 22.5 years). Sixty-one of 145 hips (42%, 95% confidence interval [CI] = 34% to 51%) experienced PAO failure during follow-up. The median survival time was 15.5 years (95% CI = 13.4 to 22.1 years). The median survival time was longer for hips with no or mild preoperative osteoarthritis: 17.0 years for Tönnis grade 0, 14.6 years for grade 1, and 12.9 years for grade 2. Higher preoperative Tönnis arthritis grades (p = 0.03) and worse WOMAC function scores (p < 0.001) were associated with an increased likelihood of failure.

Conclusions: PAO is usually effective at improving function and is effective at preserving the hip in patients ≥40 years of age provided that they have good preoperative function and no or mild preoperative osteoarthritis (Tönnis grade 0 or 1). Patients who are ≥40 years old with advanced preoperative osteoarthritis (Tönnis grade 2) and those with poor preoperative dysfunction have a high risk of therapeutic failure after PAO.

Level of evidence: Therapeutic Level IV . See Instructions for Authors for a complete description of levels of evidence.