FP7.5 Long-Term Outcomes of Combined Periacetabular Osteotomy and Hip Arthroscopy for Treatment of Acetabular Dysplasia

Background: Periacetabular osteotomy (PAO) and concomitant hip arthroscopy is an increasingly utilized method to treat acetabular dysplasia with intraarticular abnormalities. However, the literature lacks long-term data on the outcomes of this combined surgical procedure. The purpose of this study is to characterize the outcomes of combined PAO and hip arthroscopy at 10-year minimum follow-up.

Methods: A prospectively maintained database was retrospectively reviewed for patients who underwent PAO with concomitant hip arthroscopy for the treatment of acetabular dysplasia (defined as LCEA < 25 degrees) at a minimum 10-year follow-up. Hips undergoing PAO also underwent hip arthroscopy when there was clinical suspicion for significant intra-articular disease based on symptoms and imaging. Of the 80 hips undergoing combined PAO and hip arthroscopy, 68 hips (85%) successfully completed minimum 10-year follow-up. Clinical patient-reported outcomes (PROs) were measured using modified Harris Hip Score (mHHS), including assessment relative to a minimally clinically important difference (MCID) of 8 and the patient accepted symptom state (PASS) of 74. The Western Ontario and McMaster University Arthritis Index (WOMAC) pain score and University of Los Angeles California (UCLA) activity score were also measured at baseline and follow-up. Composite failure was defined as a THA conversion, non-THA revision operation, or failure to reach either MCID or PASS thresholds.

Results: The mean follow-up time was 12.2 ± 1.9 years, with a mean follow-up age of 40.3 ± 11.4 years. Improvements were observed in mean mHHS (58 ± 16 to 81 ± 20; p<0.001) and mean WOMAC pain score (8.9 ± 4.7 to 3.3 ± 4.2; p<0.001). The mean UCLA score was similar from baseline to follow-up (6.7 ± 2.6 to 6.9 ± 2.2; p = 0.43). During the follow-period, 7 hips (10%) underwent THA conversion, and an additional 8 hips (12%) underwent non-THA revision surgery. An additional 6 non-reoperation hips (9%) failed to reach either MCID or PASS, providing a composite failure rate of 31%.

Conclusions: PAO with concomitant hip arthroscopy for patients with symptomatic acetabular dysplasia and intra-articular pathology shows favorable outcomes at minimum 10-year follow-up, demonstrating a THA conversion rate of 10% and composite failure in 31% of hips.