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Clinical Outcomes After Proximal Hamstring Repair With Allograft Augmentation or Interposition for Chronic Tears: A
Sean C Clark1, Jared A Hanson1, Dustin R Lee1
1Department of Orthopedic Surgery, Mayo Clinic, Rochester, Minnesota, USA.
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 (P = .182) for the primary repair cohort. The mean follow-up for the interposition cohort was 3.5 ± 2.4 years, while it was 4.2 ± 2.5 years for the primary repair cohort (P = .227). Forty-two percent of the augmentation cohort had undergone previous surgery, compared with 5% of the interposition cohort. The time from injury to surgery for the augmentation and primary repair cohorts was 6.4 and 1.3 months, respectively (P < .001). For the interposition and primary repair cohorts, the durations were 17.8 and 1 months, respectively (P < .001). Clinical outcomes, including the Tegner Activity Scale (3 vs 3), pain with activity (47.4% vs 23.7%), and muscle spasms (36.8% vs 26.3%), did not show significant differences between the augmentation and primary repair cohorts. The augmentation cohort had a significantly worse Lower Extremity Functional Scale (LEFS) score (64 vs 75; P < .001) and were more likely to experience pain with sitting (52.6% vs 21.1%; P = .034) than the primary repair cohort. There was no significant difference in clinical outcomes between the interposition and primary repair cohorts (LEFS: 69 vs 75.5, Tegner Activity Scale: 4 vs 4; pain with sitting: 26.3% vs 27.5%; pain with activity: 42.1% vs 30%; muscle spasms: 26.3% vs 30%). Revision rates were similar between cohorts (P≥ .255).
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.
