Background: This study used Statcast-derived metrics to evaluate return to play (RTP) and performance outcomes in Major League Baseball (MLB) position players following ulnar collateral ligament (UCL) surgery.
Methods: MLB position players undergoing UCL surgery between 2017 and 2024 were identified using the Tommy John List. A 1:1 age-matched control group of uninjured MLB position players was used for performance comparisons. Performance data from the two seasons before surgery and the two seasons following RTP were collected. The data included usage, offensive performance, batted ball metrics, and defensive performance.
Results: Twenty-five MLB position players were confirmed to have undergone UCL surgery (UCL reconstruction=18; UCL repair=7). Twenty-one players (84%) returned to MLB competition with a mean time to RTP of 9.4±3.8 months. Players who underwent UCL repair returned significantly faster than those who underwent reconstruction (7.3±1.6 vs. 10.4±4.2 months, P=0.049). No statistically significant differences were observed between pre- and post-surgery performance across any metric for the full cohort. However, catchers demonstrated statistically significant improvements in average exit velocity and hard-hit percentage compared to both preoperative performance (exit velocity: P=0.04; hard-hit percentage: P=0.03) and matched controls (exit velocity: P=0.046; hard-hit percentage: P=0.04).
Conclusions: MLB position players return to competition at a high rate following UCL surgery. Among those who return, Statcast-derived offensive and defensive metrics demonstrate that postoperative changes in performance are minimal and statistically insignificant. Interestingly, catchers demonstrated paradoxical improvements in both postoperative average exit velocity and hard-hit percentage. Level of evidence: III.
Keywords: Batted ball profile; Catcher performance; Exit velocity; Statcast; Major League Baseball.