Hand size association with ulnar collateral ligament reconstruction in professional baseball players

Abstract

BackgroundUlnar collateral ligament (UCL) injuries in professional baseball remains a significant problem with debate as to which are the greatest risk factors. Currently, it is unknown if hand size should be considered a predictor for UCL injury. A larger or smaller hand size could have implications on fatigue of the forearm musculature and thus varying amounts of strain seen by the ulnar collateral ligament. Hypothesis/PurposeThe purpose of this study was to investigate if there is a correlation between hand size and history of UCL tear requiring a reconstruction. We hypothesize that a smaller hand size will be correlated with higher UCL reconstruction rates in professional baseball players. MethodsOne-hundred and eighty-nine professional players from one Major League Baseball organization were recruited in this retrospective study. Four different measurements were used for hand size including: the distance from the tip of long finger to wrist crease (closed fingers), the distance from the thumb tip to the small fingertip (closed fingers), the distance between thumb tip and small fingertip (spread fingers) and a modified Nirschl measurement (closed fingers). Statistical analysis including t test, Chi-Square test, Pearson correlation, and binary logistic regression were performed to determine the statistical significance between these hand size measurements and a history of UCL reconstruction. ResultsThere were 25/189 (13.2%) of players with a history of UCL reconstruction surgery. The mean age of UCL reconstruction group (23.6 ± 3.3years) was younger than the non-reconstruction group (26.2 ±3.6) (p=0.001). Statistical analysis demonstrated the distance between thumb tip and small fingertip (spread fingers) was smaller in the UCL reconstruction group compared to the non-reconstruction group (20.33 ± 1.18cm vs 20.98 ± 1.03cm; p=0.024) and the modified Nirschl measurement (closed fingers) was shorter in the UCL reconstruction group (14.45 ± 0.7cm vs 14.86 ± 0.91cm; p=0.013). Findings were most notable in players younger than 21 years old with UCL reconstruction rates of (57.1%) versus players older than 21 years (9.7%) (p<0.001). Statistical analysis demonstrated a correlation and regression between injury probability and hand measurements (p=0.01). ConclusionThis study demonstrated that a smaller hand size did correlate with a history of UCL reconstruction in this professional baseball population of players. Further studies are warranted to investigate these associations.