Clinical Outcomes After Proximal Hamstring Repair With Allograft Augmentation or Interposition for Chronic Tears: A Multicenter Propensity-Matched Analysis.

Background: Chronic hamstring tears can result in challenging surgical repairs. Allografts may be used to augment the repair; however, there is limited clinical evidence supporting their use. Purposes: To (1) evaluate clinical outcomes of patients who underwent proximal hamstring repair with allograft augmentation or interposition and (2) compare them to matched controls who underwent primary hamstring repair. Study Design: Cohort study; Level of evidence, 3. Methods: A total of 117 patients who underwent proximal hamstring repair were included, consisting of 19 allograft augmentations, 20 allograft interpositions, and 78 primary repairs. Allograft cohorts were propensity-matched with those who underwent primary repair in a 1 to 2 ratio. Clinical outcomes were obtained at the final follow-up. Data were extracted using continuous variables, with normality reported as mean values ± standard deviation, and non-normality reported as median values with interquartile ranges (IQR). Results: The median follow-up of the augmentation cohort was 1.9 [IQR, 0.8-3.9] years, while it was 3.2 [IQR, 1.6-5.1] years ( Conclusion: Proximal hamstring repair for chronic tears with allograft augmentation or interposition is a reproducible procedure that results in satisfactory, yet poorer clinical outcomes compared with patients who underwent primary hamstring repair. These procedures should be considered in symptomatic patients with chronic tears that are not amenable to primary repair.