Summary

Early improvements in PROMs following hip arthroscopy, assessed by 6-month MCID, predicted clinically meaningful outcomes at 5-year follow-up, underscoring the importance of progressive but cautious recovery during these six months.

Abstract

Introduction

Despite the increasing utilization of hip arthroscopy and identification of predictors of poor outcomes, the impact of short-term improvement on long-term functional outcomes has been understudied. The purpose of this study was to determine whether early improvements in patient-reported outcome measures (PROMs) 6 months after hip arthroscopy predict five-year outcomes.

Methods

A retrospective review of prospectively-collected data identified patients >18 years that underwent hip arthroscopy by a single surgeon for the treatment of symptomatic labral tears secondary to femoroacetabular impingement (FAI). Included patients had a Tönnis grade <2 and complete PROMs at baseline, 6-month, and minimum 2-year follow-up. The minimal clinically important difference (MCID) for the modified Harris Hip Score (mHHS) was used to stratify patients into cohorts based on high improvement (HI) versus low improvement (LI) at 6 months. PROMs were compared between these cohorts at 1-5 years postoperatively by rates of MCID achievement and linear mixed effects modeling.

Results

Overall, 175 patients met inclusion criteria. Of these, 131 HI patients were compared to 44 LI patients. At 5 years, 88.3% of HI patients reached MCID, versus 42.1% of LI patients. By multivariate logistic regression, achievement of 6-month MCID (adjusted odds ratio [AOR], 17.42) and labral management (augmentation, relative to debridement: AOR, 14.5) predicted achievement of 5-year MCID. mHHS scores were greater for HI versus LI patients at all time points through 3-year follow-up, but were not significantly different at 4 and 5 years.

Conclusion

Early improvements in PROMs following hip arthroscopy, assessed by 6-month MCID, predicted clinically meaningful outcomes at 5-year follow-up, underscoring the importance of progressive but cautious recovery during these six months. Despite this, LI patients continued improving for 5 years and by absolute PROM scores, did not differ significantly from HI patients at 5-year follow-up, demonstrating that late functional improvement is still possible in patients in the event of a poor 6-month rehabilitation period.