Do Active Pao Patients Maintain Their Activity Levels Over Mid-term Follow-up?
Authors: Okoroafor Ugochi , Pascual-Garrido Cecilia , Schwabe Maria , Abu-Amer Wahid , Clohisy John C. 
Published: July 2019

Objectives: Periacetabular osteotomy (PAO) is an established hip preservation technique for skeletally mature patients with symptomatic acetabular dysplasia. For athletes and physically active individuals undergoing PAO, returning to and maintaining a high level of activity postoperatively is a priority. The purpose of this study was to evaluate maintenance of activity levels at mid to long-term follow-up in active patients treated with the PAO. Methods: We conducted a retrospective review of patients who underwent PAO for symptomatic hip dysplasia at our institution from June 2006-August 2013. Patients were identified by review of the prospective Institutional Hip Database, which contains all patients who are treated with PAO. All patients who underwent PAO for acetabular deformity correction and had a UCLA score of 7 or higher preoperatively at time of surgery and at least 5 years of follow up were included in the study. Exclusion criteria consisted of patients with a preoperative UCLA score less than 7, history of trauma, neuromuscular or connective tissue disorder, diagnosis other than developmental hip dysplasia, previous surgery, or severe deformities such as seen after Perthes or SCFE. Patient-reported outcome measures included the UCLA activity score, modified Harris Hip Score (mHHS), and the Western Ontario and McMaster Universities Osteoarthritis Index (WOMAC), and the minimal clinically important difference (MCID) was identified. Maintenance of high level of activity was defined, as previously reported, as a UCLA score of 7 or higher at final follow-up. Radiographic parameters included the lateral center-edge angle (CEA), anterior CEA, acetabular index, and Tönnis classification. Statistical significance was defined as a p-value < 0.05. Results: A total of 360 PAOs were identified. Of these, 70 patients (79 hips) met the inclusion criteria, and follow-up was obtained in 59 patients (66 hips) (83.5%) and included in the final analysis. The mean age was 25 years (range 14-47 years), and mean follow-up was 6.8 years (range 5-11 years). All hips underwent a PAO, with concomitant surgeries being performed in 63/79 hips (80%). Femoral head/neck osteochondroplasty was performed in 62/66 hips (94%). Postoperative UCLA scores demonstrated maintenance of high activity level with UCLA score of at least 7 in 46/66 hips (70%). Harris hip score and WOMAC (total and all subsets) improved significantly (p<0.05) (Table 1). 77 percent of hips achieved MCID with mHHS, and 65% of hips achieved MCID with the WOMAC pain score. Lateral CEA, anterior CEA, acetabular inclination, true lateral alpha angle, Dunn alpha angle, and frog lateral alpha angle were significantly improved at final follow up (p<0.01). Tönnis classification showed progression from Grade 0 to Grade 1 in 3 hips. One hip was Tönnis grade 2 preoperatively and did not progress postoperatively. There were 0 conversions to total hip arthroplasty. There were 9 patients with clinical failure, signified by mHHS<70 at the latest follow-up. Conclusion: To our knowledge, this study is the first to evaluate level of activity in active patients at mid to long-term follow-up after PAO surgery. These data indicate excellent overall clinical outcomes (Mean UCLA-8, mHHS-88) with maintenance of high activity levels in 70% of patients. This information can provide surgeons and active patients with valuable information regarding mid to long-term activity profiles after PAO surgery. [Table: see text]