Operative versus Nonoperative Treatment of Proximal Hamstring Avulsions.

Background: Operative treatment is widely used for acute proximal hamstring avulsions, but its effectiveness compared with that of nonoperative treatment has not been shown in randomized trials.

Methods: In this noninferiority trial at 10 centers in Sweden and Norway, we enrolled patients 30 to 70 years of age with a proximal hamstring avulsion in a randomized trial and a parallel observational cohort. Treatments were operative reinsertion of the tendons or nonoperative management. The primary end point was the Perth Hamstring Assessment Tool (PHAT) at 2 years of follow-up. Secondary outcomes included scores on the Lower Extremity Functional Scale (LEFS).

Results: A total of 119 patients were enrolled in the randomized trial and 97 patients in the observational cohort. In the per-protocol analysis of the randomized trial, the mean (±standard deviation) PHAT scores were 79.9±19.5 and 78.5±19.4 in the operative and nonoperative groups, respectively (PHAT scores range from 0 to 100, with higher scores indicating higher function). The prespecified noninferiority limit of 10 points was not crossed (mean difference, -1.2; 95% confidence interval [CI], -8.6 to 6.2; P=0.009 for noninferiority). Analyses of secondary outcomes, including a mean difference in the LEFS score of -1.6 (95% CI, -5.2 to 2.0), aligned with the primary outcome. The observed numbers of adverse events in the randomized trial were nine in the operative group versus three in the nonoperative group (odds ratio, 0.3; 95% CI, 0.1 to 1.2). In the analysis of the observational cohort, the mean PHAT score difference between the nonoperative and operative treatment groups was -2.6 (95% CI, -9.9 to 4.6).

Conclusions: In patients 30 to 70 years of age with proximal hamstring avulsions, nonoperative treatment was noninferior to operative treatment. (Funded by Afa Försäkring and others; ClinicalTrials.gov number, NCT03311997.).