Performance Outcomes After Hook of Hamate Fractures in Major League Baseball Players

Context: Major League Baseball (MLB) players are at risk of hook of hamate fractures. There is a paucity of data assessing the effect of a hook of hamate fracture on MLB players’ future athletic performance. Objective: To determine if MLB players who sustain hook of hamate fractures demonstrate decreased performance upon return to competition when compared with their performance before injury and that of their control-matched peers. Design: Retrospective case-control design. Setting: Retrospective database study. Participants: 18 MLB players who sustained hook of hamate fractures. Methods: Data for 18 MLB players with hook of hamate fractures incurred over 26 seasons (1989–2014) were obtained from injury reports, press releases, and player profiles (www.mlb.com and www.baseballreference.com). Player age, position, number of years in the league, mechanism of injury, and treatment were recorded. Individual season statistics for the 2 seasons immediately prior to injury and the 2 seasons after injury for the main performance variable—Wins Above Replacement—were obtained. Eighteen controls matched by player position, age, and performance statistics were identified. A performance comparison of the cohorts was performed. Main Outcome Measures: Postinjury performance compared with preinjury performance and matched-controls. Results: Mean age at the time of injury was 25.1 years with a mean of 4.4 seasons of MLB experience prior to injury. All injuries were sustained to their nondominant batting hand. All players underwent operative intervention. There was no significant change in Wins Above Replacement or isolated power when preinjury and postinjury performance were compared. When compared with matched-controls, no significant decline in performance in Wins Above Replacement the first season and second season after injury was found. Conclusion: MLB players sustaining hook of hamate fractures can reasonably expect to return to their preinjury performance levels following operative treatment.