Background: The MLB draft is a common route for players to enter professional baseball in the United States. Individuals taken in earlier rounds are typically higher-performing players. When looking at pitchers specifically, higher performance at the amateur level may be associated with increased frequency of adaptive change in the throwing elbow.
Purpose/Hypothesis: To determine if players taken in earlier rounds of the MLB draft have a greater frequency or extent of pathological change in the elbow, as measured by dynamic stress ultrasound.
Study Design: Retrospective Cohort Study Methods: Dynamic stress ultrasounds (SUS) were performed over an 18-year period on the dominant and nondominant arms of 651 professional pitchers. The 383 players who were drafted were grouped according to which round they were drafted in (rounds 1-5, 6-10, 11-20, 21+). Groups were compared with respect to “relative” ulnar collateral ligament thickness (dominant – nondominant), “relative” ulnohumeral joint laxity (joint space distance under stress – distance at rest), and the presence of pathology (calcifications, tears, hypoechoic foci, osteophytes). Additionally, a subgroup analysis was done to compare progression of SUS findings over a 3-year period in players for which data was available.
Results: Draft round groups did not differ by age, number of prior spring trainings, or handedness. Comparing baseline measurements, there was no significant relationship between draft round and relative UCL thickness (P = .932), relative laxity (P = .996), or presence of pathology detectable on SUS (P = .642). However, increased relative UCL thickness was significantly associated with the presence of pathology on SUS (OR: 1.45, 95% CI [1.26-1.69], P \u3c .001). Longitudinally, there was no significant relationship between draft round and 3-year progression of relative laxity, relative UCL thickness, or clinical progression of pathology.
Conclusion: Higher-performing pitchers are drafted earlier in the MLB draft. This may be attributable to peak pitch velocity, in-game performance, visibility gained during player showcases, or any number of other sport-specific variables. However, despite this, there was no significant relationship between draft round and adaptive changes to the elbow on SUS
