Poster 205: Long-Term Outcomes for Patients Undergoing Revision Hip Arthroscopy

Abstract

Objectives: Previous studies have reported outcomes after revision hip arthroscopy at mid-term follow-up. These studies demonstrate that patients can expect clinical improvement and low rates of reoperation following their revision surgery. However, in comparison to primary hip arthroscopy patients they experience worse outcomes. The purpose of this study was (1) To evaluate long-term outcomes after revision hip arthroscopy and (2) to identify factors that contribute to poorer outcomes. Methods: Patients who underwent revision hip arthroscopy for FAIS between 1/2012-9/2015 were reviewed. Patients were excluded if they underwent revision hip arthroscopy for a reason other than FAIS, underwent staged or prior PAO, had Tönnis grade > 1, had a history of congenital hip disorder (e.g., slipped capital femoral epiphysis), or were missing 8+ year follow-up. Patient-reported outcome (PRO) measures were collected both pre- and post-operatively including Hip Outcome Score Activities of Daily Living (HOS-ADL) and Sports Scale (HOS-SS), modified Harris Hip Score (mHHS), and international Hip Outcome Tool (iHOT-12). Minimal clinically important difference (MCID) and patient acceptable symptom state (PASS) thresholds were calculated using the distribution and anchor methods, respectively. Rates of MCID and PASS achievement were then evaluated. Rates of reoperation including repeat revision hip arthroscopy and conversion to total hip arthroplasty (THA) were evaluated. Patients were also divided into clinical successes and failures and compared. A clinical failure was defined as failure to achieve MCID or PASS for any PRO or undergoing a reoperation. Results: A total of 43 patients (72% female; age: 30.1 ± 10.3 years; BMI: 25.8 ± 6.0 kg/m2) met criteria for inclusion. Average follow-up was 9.3 years. At last follow-up there were significant improvements across all PROs (p < 0.001, for all). MCID achievement at final follow-up for each PRO was ≥ 56.5%, with achievement of MCID in any PRO occurring in 73.9% of patients. PASS achievement at final follow-up for each PRO was ≥ 29.6%, with achievement of PASS in any PRO occurring in 63.0% of patients. PASS achievement was 75.7% at two years and 75.8% at five years. Incidence of secondary revision hip arthroscopy was 23.3% and THA was 14.0%, occurring at mean 3.9 ± 2.8 years and 4.2 ± 3.0 years following index revision, respectively. 22 patients were considered clinical successes, and 21 patients were determined to be clinical failures. Both groups demonstrated similar age (28.6 ± 8.5 years vs 31.6 ± 11.9, p = 0.351), sex (77.3% female vs 66.7% female, p = 0.438), and BMI (25.7 ± 7.9 vs 25.9 ± 3.6, p = 0.915). Additionally, clinical successes and failures had similar preoperative PROs (p ≥ 0.133, for all). Presence of preoperative pain for over two years occurred more frequently in clinical failures (45.5% vs 76.2%, p = 0.039). Tönnis grade 1 was also present at a higher rate amongst clinical failures (0% vs 23.8%, p = 0.015). Conclusions: Patients undergoing revision hip arthroscopy can see significant clinical improvement, particularly within the first five years following surgery. However, some patients may see clinical decline beyond eight years post-operatively. Revision hip arthroscopy is associated with relatively high reoperation rate. Those with greater Tönnis grade on preoperative radiographs and increased prevalence of chronic preoperative pain were less likely to achieve a clinical success.