Ulnar Collateral Ligament Tear in Elite Baseball Pitchers: Are High School Showcase Exposures Associated With Injury?
Authors: Kriz Peter K. , Staffa Steven J. , Kriz John P. , DeFroda Steven 
Published: August 2022

Background:

Ulnar collateral ligament reconstruction (UCLR) surgeries have increased significantly in amateur and professional baseball pitchers. Although showcase participation has been considered an injury risk factor, limited data are available to corroborate this association.

Hypothesis:

Elite pitchers achieving fastball velocities ≥90, ≥92, and ≥95 mph at younger ages would be more likely to undergo UCLR earlier in their careers compared with pitchers not achieving these velocity thresholds at younger ages. Elite pitchers participating in high showcase volumes would be more likely to undergo UCLR compared with elite pitchers participating in fewer showcases.

Study Design:

Cohort study; Level of evidence, 3.

Methods:

Descriptive, showcase performance, and injury data from pitchers selected in the first 5 rounds of the Major League Baseball draft (2011-2020) were gathered from publicly available databases. Continuous and categorical variables for pitchers undergoing UCLR and those not undergoing UCLR were compared, and multivariable analysis was performed using logistic regression. We used standard deviations (SDs) of ±1 SD of mean age at first UCLR to define early-career versus late-career UCLR subgroups after normal distribution was confirmed (Shapiro-Wilk test; P = .183). The “early” UCLR group was defined as ≤−1 SD (19.09 years), whereas the “late” UCLR group was defined as ≥+1 SD (24.79 years). Trends in time were evaluated using linear regression.

Results:

Of the 845 pitchers selected, 659 pitchers (78.0%) had retrievable showcase performance data. Of the 845 pitchers, 229 (27.1%) underwent UCLR. Peak fastball velocity recorded at showcases was the strongest predictor of UCLR (adjusted odds ratio, 1.19; 95% CI, 1.02 to 1.39; P = .03). Peak fastball velocity in high school (HS) was significantly higher among pitchers who underwent UCLR compared with pitchers in the no-UCLR group (91.57 vs 90.71 mph, respectively; 95% CI, −1.43 to −0.29; P < .01). Age at which pitchers participated in their first HS showcase was significantly younger for the early versus the late UCLR group (15.53 vs 16.51 years, respectively; 95% CI, −1.53 to −0.41; P < .01). Elite pitchers with early UCLR participated in nearly twice as many showcases compared with the late UCLR group (5.38 vs 2.89, respectively; 95% CI, 0.43 to 4.54; P = .02). The mean number of HS showcases that elite pitchers attended more than doubled during the 2011-2020 study period (from 2.88 to 6.00 total showcases; P < .001). Mean age at which pitchers attended their first HS showcase steadily declined as well over the 10-year period (from 16.52 to 15.63 years; P < .001).

Conclusion:

Peak fastball velocity was the strongest predictor of UCLR in elite pitchers before initiating professional careers. Elite amateur pitchers attended more showcases at younger ages in a decade-long trend. Overall, the variables included in this multivariable analysis were weak predictors, explaining only 3.8% of the variance in UCLR rates.