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 ( < .001). By multivariable logistic regression, achievement of 6-month MCID (adjusted odds ratio [AOR], 17.43; < .001) and labral management (augmentation, relative to debridement: AOR, 14.5; = .01) predicted achievement of 5-year MCID. mHHS scores were greater for HI versus LI patients through 3-year follow-up ( < .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 ( > .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.