Six-Month Functional Scores Predict 5-Year Achievement of the Minimal Clinically Important Differences After Hip Arthroscopy for Symptomatic Acetabular Labral Tears.

Background: Despite the increasing utilization of hip arthroscopy and identification of predictors of poor outcomes, the effect of short-term improvement on long-term functional outcomes has been understudied.

Purpose: To determine whether improvements in patient-reported outcomes (PROs) 6 months after hip arthroscopy predict 5-year outcomes.

Study design: Case-control study.

Methods: A retrospective review of prospectively collected data identified patients ≥18 years who underwent primary hip arthroscopy by a single surgeon for the treatment of symptomatic labral tears. Included patients had a Tönnis grade <2 and completed PROs at baseline, 6-month, and minimum 2-year follow-up, and annually thereafter. The minimal clinically important difference (MCID) for the modified Harris Hip Score (mHHS), 8 points, was used to stratify patients into cohorts based on high improvement (HI) versus low improvement (LI) at 6 months. PROs were compared at 1, 2, 3, 4, and 5 years postoperatively by rates of MCID achievement and linear mixed-effects modeling. Subsequent surgery rates were compared by chi-square or Fisher exact tests, as appropriate.

Results: Overall, 175 patients (age, 37.2 ± 11.4 years; 52.0% female) met inclusion criteria. Of these, 131 HI patients were compared with 44 LI patients. At 5 years, 88.3% of HI patients reached MCID, versus 42.1% of LI patients (P < .001). By multivariable logistic regression, achievement of 6-month MCID (adjusted odds ratio [AOR], 17.43; P < .001) and labral management (augmentation, relative to debridement: AOR, 14.5; P = .01) predicted achievement of 5-year MCID. mHHS scores were greater for HI versus LI patients through 3-year follow-up (P < .05) but were not significantly different at 4 and 5 years. Subsequent surgery rates were 9.9% and 11.4% in HI versus LI patients, respectively (P > .05).

Conclusion: The study demonstrates that early functional improvements after hip arthroscopy, assessed by 6-month MCID, predicted clinically meaningful outcomes at 5-year follow-up, underscoring the importance of early cautious recovery to prioritize labral healing while also meeting appropriate, stepwise rehabilitation milestones to advance functionally during these 6 months. Despite this, LI patients continued improving for 5 years, demonstrating that late functional improvements are still possible for certain patients in the event of a poor 6-month rehabilitation period.