Clohisy, John C

Abstract Background: Long-term outcomes of FAI surgery are critical to understand it’s hip preserving ability, yet few studies have reported mid to long-term survivorship following FAI surgery. The purpose of this study was to report rates of treatment failure after first-generation FAI surgery at an average 10- year follow-up. Methods: A prospective, multicenter cohort study assessed patients treated for FAI with hip arthroscopy or surgical dislocation by seven surgeons at four institutions from 2008 to 2012. Inclusion criteria included primary surgery and diagnosis of isolated cam or combined cam/pincer type FAI. At an average 10-year follow-up, 362/452 eligible hips (80.1%) achieved follow-up. Cox proportional hazards model was used to identify predictors of conversion to total hip arthroplasty (THA). Results: Three hundred and sixty two hips were evaluated at a mean of 10.0 ± 2.3 years follow-up. At time of final follow-up, 34 hips (9.2%) had undergone conversion to THA at a mean of 5.2 ± 3.1 years post-operatively. An additional 18 patients (4.9%) underwent non-arthroplasty revision preservation surgery at a mean of 2.0 ± 1.5 years post-operatively. The Kaplan Meier survivorship rates after 5 and 10 years of surgery were 94.9% and 95.2% for conversion to THA and 91 % and 95.2% for revision hip preservation. Older age (HR:1.06, CI: 1.01-1.10; p=0.009), BMI≥30 (HR:4.14, CI:1.52-11.24, p=0.005), male sex (HR:3.23, CI: 1.18-9.09, p=0.02), and lower baseline mHHS (HR:1.03, CI: 1.01-1.04, p=0.01) were significant predictors of conversion to THA. Conclusion: This study demonstrates that FAI surgery yields durable outcomes with the majority of patients (85.9%) not requiring revision surgery or conversion to total hip arthroplasty at an average 10 years. Age 30 years, male sex, and obesity were significantly associated with the risk of THA conversion.