Pitch Performance After Ulnar Collateral Ligament Surgery in Major League Baseball Pitchers

Background: Return to performance after ulnar collateral ligament (UCL) surgery in Major League Baseball (MLB) pitchers has been investigated; however, pitch-specific return to performance using several advanced metrics has been minimally studied. Purpose: To evaluate pitch performance 1, 2, and 3 seasons after UCL surgery in MLB pitchers. Study Design: Case series; Level of evidence, 4. Methods: tests, as well as binary logistic regression to identify predictors of returning to performance. Return to preinjury pitch performance was also evaluated. Results: The mean age was 26.8 + 3.6 years, 74.1% of the included pitchers were right-handed, and 42.6% were starting pitchers. All individual pitches had recovered to their preoperative velocity levels by their second season back from surgery. Multiple pitches showed alterations returned to full performance at a higher than 44% in the horizontal and vertical approach angles above the mean. All pitches had significantly longer release extensions and regained their velocity and spin rate nearly 70% of the time by their third season back. Horizontal and vertical movement also recovered well for each pitch type. Nearly all pitchers returned to performance in their fastballs and sliders' Stuff+, Location+, and Pitching+, while the remaining pitches analyzed trended to not return to performance as frequently. No single pitch returned to full performance at a higher than 44% rate. Binary logistic regression did not identify any significant predictors for returning to performance in any pitch. Conclusion: Pitch-specific differences in return to performance exist after UCL surgery. No pitch returned to full performance at a higher than 44% rate 3 seasons after returning from injury, with changeups faring the best. All pitches had recovered to their preoperative mean velocity and movement levels by 2 seasons prior. Nearly all pitchers returned to performance in fastball and slider physical pitch qualities (Stuff+), strike-zone command (Location+), and overall ability (Pitching+) while sinkers, curveballs, changeups, cutters, and splitters struggled more frequently in these metrics. Altogether, we believe this study better informs MLB players and teams about expectations regarding return to performance of specific pitch types after UCL surgery.