Summary

Most patients who undergo open proximal hamstring repair achieve minimally clinically important differences (MCIDs) in hip-related outcome measures by 6 months post-surgery, with chronic symptoms negatively impacting and severe preoperative pain positively influencing the likelihood of achieving MCIDs.

Abstract

Introduction

Understanding the minimal clinically important difference (MCID) for a given procedure and its associated patient-reported outcome measures (PROMs) has become a critical component of evaluating success in orthopedic surgery. The MCIDs for the International Hip Outcome Tool (iHOT-33) and Modified Harris Hip Score (mHHS) have been defined for open proximal hamstring repair. However, how reliably and how quickly patients achieve the MCIDs for each of these PROMs after open proximal hamstring repair is unknown.

Methods

This was a retrospective review of prospectively collected data from our institution’s hip preservation registry. The mHHS and iHOT-33 were collected preoperatively and at 6-, 12-, and 24-months post-operatively. The MCIDs for open proximal hamstring repairs, as established in previous studies, were defined as an improvement of 12.6 and 11.8 in the iHOT-33 and mHHS, respectively, from preoperative baseline. The percentage of patients achieving MCID at each time point was determined and factors associated with achieving MCID were assessed.

Results

A total of 37 patients were included in this analysis, including 36 patients for iHOT-33 and 32 patients for mHHS. Overall, 83% of patients achieved MCID for iHOT-33 and 78% of patients achieved MCID for mHHS at 6 months. Patients who had chronic symptoms (pain for >6 months) were significantly less likely to achieve at least one of the MCIDs at 6 months (60% vs. 12.5%, p=0.04), while patients with more severe preoperative pain were significantly more likely to achieve at least one of the MCIDs at 6 months (p=0.004).

Conclusion

Most patients who achieve the MCID for iHOT-33 and mHHS following open proximal hamstring repair, do so by 6-months postoperatively. Chronic symptoms, or a preoperative pain duration of greater than six months, were associated with failure to achieve either one of the MCIDs at 6 months post-operatively. Patients with more severe preoperative pain were more likely to successfully achieve one of the MCIDs at 6 months.
Level of Evidence: IV