The Effects of Ulnar Collateral Reconstruction on Major League Pitching Performance

OBJECTIVES: A tremendous stress is placed on the elbow while pitching a baseball. Due to these stresses, Major League Baseball (MLB) pitchers are at increased risk for Ulnar Collateral Ligament (UCL) injuries. Previous studies have been limited in sample size, but have shown most players return to previous uninjured statistical levels after undergoing UCL reconstruction. We sought the largest cohort of MLB pitchers who have undergone UCL reconstruction and hypothesized that MLB pitchers do not return to their pre-injury statistical level after undergoing UCL reconstruction. METHODS: The statistics for 168 major league pitchers, who threw at least one season at the Major League level and subsequently underwent UCL reconstruction, were reviewed. Statistical data including earned run average (ERA), walks and hits per innings pitched (WHIP), win percentage, innings pitched, and salary were compared for the 3 years before and 3 years after undergoing UCL reconstruction. This data was compared to 178 age matched controlled MLB pitchers. All data was analyzed to determine the effects of UCL injury/reconstruction on pitching performance. Risk factors for reconstruction were analyzed using a multivariable generalized estimating equation (GEE) model RESULTS: Of the pitchers undergoing UCL reconstruction surgery 87% returned to the Major League Level. Of the pitchers that returned, they had a statistically significant decline in their ERA (P=0.001), WHIP (P=0.011), Innings Pitched (0.026), compared to pre-reconstruction performance. Reconstructed pitchers had a statistically significant decline in their pitching statistical performance in the season before their surgery (ERA p=0.014, WHIP p=0.036, Innings pitched p<0.001, Win Percentage p=0.004). Approximately 60% of pitchers requiring UCL reconstruction had surgery with in the first 5 years of being in the Major Leagues. Compared to age matched controls, the reconstructed pitchers had statistically more major league experience at the same age suggesting that arm stress from earlier Major League experience contributed to injury. This was validated by a multivariable GEE model that examined risk factors showing an increase in MLB experience being a risk factor for requiring surgery (p<0.001). CONCLUSION: This is the largest cohort of MLB pitchers, to date, that have undergone UCL reconstruction. Its results suggest that UCL reconstructive surgery does a tremendous job in allowing players to return to their same level of sport. This study is the first to describe a decline in pitching performance after undergoing reconstruction. It also found that there is a statistically significant decline in pitching performance the year before reconstructive surgery and this decline was found to be a risk factor for requiring surgery. We also found that there is an increased risk of players requiring surgery if they enter the Major Leagues at a younger age.