Background: Return to play and performance following elbow ulnar collateral ligament (UCL) reconstruction or repair in Major League Baseball (MLB) position players have not been well studied. Purpose: To evaluate return to play and return to performance using modern advanced analytics at 1 and 2 seasons following UCL surgery in MLB position players. Study Design: Cohort study; Level of evidence, 3. Methods: A retrospective analysis was performed on all 33 MLB position players who underwent primary UCL surgery between March 1, 2014, and November 1, 2024. Incidence, risk factors, and return-to-play rates were recorded. Return-to-performance analysis was conducted for 25 players who met the inclusion criteria and were compared to preoperative levels and 50 uninjured matched controls. Performance data were collected for all MLB position players using public sources. Binary logistic regression was also conducted. Results: Incidence of UCL surgery in MLB position players over the full 11-season period (2014-2024) was 2.9 ± 1.4 surgeries per season in our cohort, with an even greater average in the past 5 full seasons compared to 2014 to 2019 ( P = .21) and 1984 to 2014 ( P < .05). Cases had a significantly greater whiff percentage and fewer outs above average. A total of 81.8% returned to play at 1.5 years postoperatively (mean of 317 ± 111 days). UCL repairs (n = 8) resulted in 121 fewer days missed on average compared to reconstructions (n = 25; P < .01). Notably, position players provided significantly less value (FanGraphs wins above replacement fWAR) after returning. There were otherwise no differences in any mean offensive or defensive metric. Controls had higher proportions meeting prior performance levels in nearly every metric for the first and second seasons back. Preinjury weighted runs created plus (wRC+) in cases was the only predictor for returning to performance in fWAR postoperatively. Conclusion: Annual UCL surgery rates in MLB position players have tripled in recent seasons. Less contact and defensive ability were associated with getting UCL surgery. Over 80% of players returned to play by 1.5 years postoperatively, with those who underwent UCL repairs returning faster. Most performance metrics return at high rates, but the significant decline in player value after returning can likely be explained by decreased workload and possibly a slight decline in offensive performance.
Mastroianni et al. (Sun,) studied this question.