Frequency of Tommy John Surgery in NCAA Division I College Pitchers Versus Weather Conditions

Ulnar collateral ligament reconstruction (UCLR) is a common elbow procedure in baseball pitchers. Previous studies of Major League Baseball pitchers identified the weather as a potential risk factor, as warmer climates enable more annual playing time and increase overuse injury risks.

To determine whether weather conditions play a role in UCLR rates and timing for National Collegiate Athletic Association (NCAA) Division I (D1) collegiate pitchers in the United States.

Cross-sectional study; Level of evidence, 3.

A total of 320 NCAA D1 college baseball pitchers who underwent UCLR surgery between July 1, 2015, and June 30, 2022, were analyzed. Pitcher college climates were categorized as warm or cold based on their location relative to the 33rd parallel line in North America. A 2-sample independent t test was used to compare the mean UCLR rate for pitchers in warm versus cold climates. The incidence rate difference and incidence rate ratios by state and pitcher year were calculated and evaluated. The chi-square test and Poisson Regression were used to evaluate associations between pitcher year and high school pitching climate.

Among 320 total UCLRs, warm-state pitchers had a higher mean UCLR rate compared with cold-state pitchers (P = .0001). The highest number of UCLRs in warm states occurred during the sophomore year (n = 57), while the highest number of UCLRs in cold states occurred during the junior year (n = 63). Freshmen, sophomore, and senior warm state pitchers had significantly higher (incidence rate ratios [IRR] and incidence rate difference [IRD]) rates and likelihood of UCLR than their cold state counterparts (freshmen P _IRD = .0025, P _IRR = .0032; sophomore: P _IRD = .0002, P _IRR = .0003, senior: P _IRD = .0123, P _IRR = .0159). Underclassmen (freshmen and sophomores) pitchers who threw in warm high school climates had a 1.4 times higher rate of UCLRs than underclassmen pitchers from cold high school climates (P = .041).

NCAA D1 college baseball pitchers who play in warm climates undergo UCLR surgery significantly more often and significantly earlier in their collegiate careers than pitchers playing in cold climates.