Activity Level Maintenance at 10-Year Minimum Follow-up Among Active Patients Undergoing Periacetabular Osteotomy

Background: Periacetabular osteotomy (PAO) can treat pain, dysfunction, and decreased activity secondary to hip dysplasia. Patients’ pre- and postoperative activity can be measured using the University of California Los Angeles (UCLA) activity score, a validated questionnaire. Understanding return to and maintenance of activity at long-term follow-up after PAO is a priority for active patients. Purpose: To provide long-term follow-up of a previously published cohort that will help examine maintenance of activity after PAO, guide treatment decision-making, and inform patient counseling. Study Design: Case series; Level of evidence, 4. Methods: This prospective longitudinal cohort consisted of patients undergoing PAO between 2006 and 2013. Inclusion criteria included lateral center-edge angle <25°, highly active individuals (UCLA score ≥7), and 10-year minimum follow-up. UCLA, modified Harris Hip Score, and Western Ontario and McMaster Universities Osteoarthritis Index scores and descriptive information were obtained. P values <.05 were considered significant. Results: The cohort included 68 hips (86.1% follow-up; 61 patients), with 7 (10.3%) having additional surgery (4 total hip arthroplasty, 3 osteochondroplasty) at a mean 9.8 years (range, 6.0-15.8). Reoperated hips were excluded; the remaining 61 were analyzed. Mean age at PAO was 24.7 years (range, 14.7-44.8) with female predominance (74.1%). Mean follow-up was 12.5 years (range, 10.2-17.1). Of 61 hips, 54 (88.5%) either maintained high activity with a UCLA score ≥7 (n = 43; 70.5%) or had lower activity unrelated to the surgical hip (n = 11; 18.0%). When compared with preoperative values, the mean UCLA score decreased from 8.9 to 8.1 (P =.009); the modified Harris Hip Score improved from 64.6 to 88.8 (P <.001), with 49 of 61 hips (80.3%) achieving the minimal clinically important difference; and the Western Ontario and McMaster Universities Osteoarthritis Index pain score improved from 68.2 to 89.0 (P <.001), with 35 of 51 hips (68.7%) achieving the minimal clinically important difference. Hips with PAO before age 25 years were more likely to be in higher activity groups at follow-up (P =.030). Conclusion: Patients with hip dysplasia can be treated with PAO to help maintain activity and preserve the native hip. At long-term follow-up (mean, 12.5 years), 54 of 68 (79.4%) hips did not have additional surgery and either remained in the high activity group or had lower activity levels unrelated to the hip. PAO appears to be a durable hip preservation technique at 12.5-year follow-up for highly active patients.