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Hamstring Injuries in Major League Baseball Pitchers: Implications in Graft Selection for Ulnar Collateral Ligament Reconstruction

Background: Hamstring tendons are commonly harvested as autograft for ulnar collateral ligament reconstruction. There is no consensus in the literature whether the hamstring tendon should be harvested from the ipsilateral (drive) leg or contralateral (landing) leg of baseball pitchers undergoing ulnar collateral ligament reconstruction. Hamstring injuries commonly occur in baseball players, but there are no reports on their incidence specifically among Major League Baseball (MLB) pitchers, nor are there reports on whether they occur more commonly in the drive leg or the landing leg. Hypothesis: Hamstring injuries occur more commonly in the landing legs of MLB pitchers. Study Design: Descriptive epidemiology study. Methods: MLB pitchers who sustained hamstring injuries requiring time spent on the disabled list were identified from publicly available sources over 10 seasons. Demographics of the pitchers and injury and return-to-sport data were collected. Hamstring injuries to the drive leg were compared with injuries to the landing leg. Results: Sixty-five pitchers had 78 disabled list stints due to hamstring injuries over 10 seasons. The landing leg was injured in 67.9% of cases, and the most common mechanism of injury was pitching. There were no significant differences in demographics between pitchers who sustained drive leg and landing leg injuries. There was no significant difference in mechanism of injury or time to return to sport between pitchers who sustained drive leg and landing leg injuries. Conclusion: The landing leg is more commonly injured than the drive leg among MLB pitchers who sustain hamstring injuries. There is no difference in time to return to sport between pitchers who sustain drive leg and landing leg injuries. More research is required to determine whether there is a difference in performance or future injury between hamstring tendons harvested from the drive leg and the landing leg for ulnar collateral ligament reconstruction among pitchers.