Primary Ulnar Collateral Ligament Reconstruction in Major League Baseball Pitchers: An Analysis of Factors Associated With Successful Return to Preinjury Level of Performance

Background: An increasing number of Major League Baseball (MLB) pitchers are receiving ulnar collateral ligament reconstruction (UCLR). However, a substantial proportion of pitchers do not regain their preinjury level of performance. Currently, limited research has investigated the factors associated with return to level (RTL) after UCLR. Hypotheses: The authors hypothesized that (1) pitchers whose performance was primarily dependent on fastball effectiveness may face greater challenges in regaining their prior form, (2) those with a history of high workload were more likely to encounter difficulties in recovery, and (3) pitchers who exhibited suboptimal performance before injury may be less likely to achieve a full RTL. Study Design: Case-control study; Level of evidence, 3. Methods: This retrospective case-control study analyzed 174 MLB pitchers who underwent primary UCLR between 2015 and 2021. Pitchers were grouped by whether they successfully returned to level, which was defined as returning to MLB within 3 seasons after surgery and recording >100 pitches in at least 1 season. Demographics and pitching metrics were collected to identify risk factors associated with failure to return to prior performance level. Results: In this study, 132 pitchers (75.9%) were able to RTL. No significant differences were found in fastball metrics between groups. Univariate analysis revealed that players who were unable to RTL had fewer games started and innings pitched and lower total pitch counts were more frequently relievers during the index season ( P < .05). Additionally, significantly worse fielding independent pitching, earned run average, and wins above replacement (WAR) were observed in this group ( P < .05). Multivariate analysis indicated that lower preinjury WAR was identified as a significant risk factor for failing to RTL, with a cutoff value of WAR <0.15 (area under the curve, 0.771; P < .001) indicating increased risk. Conclusion: The study highlighted that players who were unable to RTL were more frequently relievers. Pitching metrics during the index year, including fewer games started, reduced innings pitched, and lower total pitch counts, were linked to failure to RTL. Performance statistics, such as worse performance in fielding independent pitching, earned run average, and WAR during the index year, were linked to an increased risk of being unable to RTL.