Summary

The purpose of this study is to examine, in patients who underwent surgical repair of chronic proximal hamstring ruptures, whether increased muscle atrophy, as assessed with the Goutallier classification system, is associated with worse patient-reported outcomes (PROs). A secondary aim of this study is to evaluate risk factors for increased muscle atrophy after proximal hamstring rupture.

Abstract

Purpose

Increased time to surgery has been associated with poorer clinical outcomes after surgical treatment of proximal hamstring ruptures, though the etiology for this remains unclear. The purpose of this study was to evaluate whether degree of muscle atrophy, as assessed using the Goutallier classification system, is associated with worse outcomes following surgical treatment of chronic proximal hamstring ruptures.

Methods

Patients who underwent repair of proximal hamstring ruptures from 2012 to 2020 with minimum 2-year follow-up were retrospectively reviewed. Patients were included if they underwent primary open repair of a proximal hamstring rupture at least 6 weeks after the date of injury and accessible preoperative magnetic resonance imaging (MRI). Exclusion criteria were: allograft reconstruction, endoscopic repair, or prior ipsilateral hip surgery. Eligible patients were administered validated surveys: the modified Harris Hip Score (mHHS) and the Perth Hamstring Assessment Tool (PHAT). The degree of fatty atrophy on preoperative MRI was independently graded by two musculoskeletal radiologists using the Goutallier classification. Multivariate linear regression analysis was performed using age, sex, BMI, time from injury-to-surgery, number of tendons torn, distance of tendon retraction, concomitant sciatic neurolysis, and Goutallier grade to evaluate associations with mHHS and PHAT scores.

Results

Complete data sets were obtained for 27 patients. A majority of this cohort was male (63.0%), with a mean age of 51.5±11.8 years and BMI of 26.3±3.8. The mean follow-up time was 62.6±23.1 months, and the mean time from injury-to-surgery was 20.4±15.3 weeks. For the Goutallier grading, the inter-reader weighted kappa coefficient was 0.655. Regression analysis demonstrated increased age was significantly predictive of muscle atrophy (ß=0.623, p=0.005). Age was also found to be a significant predictor of poorer mHHS score (ß=-0.749; p=0.037. No other variables, including retraction grade of atrophy, were found to be significant predictors of atrophy or mHHS and PHAT.

Conclusions

Increasing age, but not time from injury to MRI, was significantly predictive of increased hamstring muscle atrophy on preoperative MRI in patients with chronic ruptures. Although age was significantly correlated with poorer mHHS scores, the degree of atrophy itself was not shown to be an independent predictor of clinical outcomes.