Progression of Hamate Hook Stress Reactions in Elite Baseball Players

BACKGROUND: Hamate hook fractures can occur as a result of repetitive contact with the knob of the bat used in the sport of baseball. Hamate hook excision has resulted in excellent outcomes and return to sport (RTS) in elite baseball players. The ideal treatment for hamate stress response before the development of a fracture line is unknown. PURPOSE: To report the outcomes of elite baseball players with hamate bone edema. STUDY DESIGN: Case series; Level of evidence, 4. METHODS: We reviewed the medical records of all elite baseball players with hamate bone edema consistent with a stress response at 2 institutions. Players were eligible for inclusion if they played collegiate or professional baseball at the time of initial injury, had magnetic resonance imaging (MRI) showing hamate bone edema, and had no radiographic evidence of acute fracture lines at initial presentation. RESULTS: A total of 4 players with a mean age of 22.8 years were included. All injuries occurred in the nondominant hand. All athletes had normal initial wrist radiographs and MRI showing hamate edema but no fracture line. Patients returned to play as tolerated and developed an acute injury at an average of 25.8 days (range, 10-56 days) from the initial presentation. Repeat radiographs demonstrated acute hamate hook fractures in all 4 (100%) athletes. All 4 athletes underwent hamate hook excision. There were no postoperative complications. All athletes returned to sport at their previous level of competition at a mean of 5.3 weeks (range, 3.6-7.3 weeks). CONCLUSION: There is a high rate of hamate bone edema progression to acute hamate hook fracture in elite baseball players, with 100% RTS at preinjury level after hamate hook excision. We therefore recommend against prolonged rest. Continuation of play with hamate bone edema followed by hamate hook excision for acute fracture limits the time missed and obtains a faster RTS in elite baseball players.