List, Jelle P. van der

Background: Recent epidemiologic reports have demonstrated rising injury rates in Major League Baseball (MLB) and Minor League Baseball (MiLB). Although several studies have recently been published on specific injuries, the majority of injuries have not yet been formally studied. Purpose: The purpose of this study is to (1) generate a summative analysis of all injuries that occur in MLB and MiLB, (2) identify the 50 most common injuries, and (3) generate focused reports and fact sheets on the characteristics of each of those diagnoses. Study Design: Case series; Level of evidence, 4. Methods: The MLB Health and Injury Tracking System was used to identify injuries occurring in MLB and MiLB players from 2011 to 2016. Injuries were defined as those that occurred during normal baseball activity and resulted in at least 1 day out of play. A multitude of player and injury characteristics were analyzed, and detailed reports of the 50 most commonly occurring injuries were generated. Results: A total of 49,955 injuries occurred during the study period; 45,123 were non–season ending, and they resulted in 722,176 days out of play. The mean (median) days missed per injury was 16 (6) days. Overall, 39.1% of all injuries occurred in pitchers. The upper extremity was involved in 39% of injuries, while 35% occurred in the hip/groin/lower extremity. Surgery was required in 6.5% of cases, and 9.7% of injuries were season ending. Hamstring strains were the most common injury (n = 3337), followed by rotator cuff strain/tear (n = 1874), paralumbar muscle strain (n = 1313), biceps tendinitis (n = 1264), oblique strain (n = 1249), and elbow ulnar collateral ligament injury (n = 1191). The diagnoses that were most likely to end a player’s season were elbow ulnar collateral ligament injury (60% season ending) and superior labrum anterior and posterior tear (50.9% season ending). Conclusion: Contrary to prior reports relying on disabled list data, the annual number of injuries in professional baseball remained steady from 2011 to 2016. Similar trends were noted for the annual number of days missed and mean days missed per injury. Although the mean days missed per injury was high (16), the median was much lower at 6 days.

Background: Although vascularity plays a critical role in healing after ulnar collateral ligament (UCL) reconstruction, intraosseous blood flow to the medial epicondyle (ME) and sublime tubercle remains undefined. Purpose: To quantify vascular disruption caused by tunnel drilling with the modified Jobe and docking techniques for UCL reconstruction. Study Design: Controlled laboratory study. Methods: Eight matched pairs (16 specimens) of fresh-frozen cadaveric upper extremities were randomized to 1 of 2 study groups: docking technique or modified Jobe technique. One elbow in each pair underwent tunnel drilling by the assigned technique, while the contralateral elbow served as a control. Pregadolinium and postgadolinium magnetic resonance imaging were performed to quantify intraosseous vascularity within the ME, trochlea, and proximal ulna. Three-dimensional computed tomography (CT) and gross dissection were performed to assess terminal vessel integrity. Results: Ulnar tunnel drilling had minimal impact on vascularity of the proximal ulna, with maintenance of >95% blood flow for each technique. Perfusion in the ME was reduced 14% (to 86% of baseline) for the docking technique and 60% (to 40% of baseline) for the modified Jobe technique (mean difference, 46%; P = .029). Three-dimensional CT and gross dissection revealed increased disruption of small perforating vessels of the posterior aspect of the ME for the modified Jobe technique. Conclusion: Although tunnel drilling in the sublime tubercle appears to have a minimal effect on intraosseous vascularity of the proximal ulna, both the docking and modified Jobe techniques reduce flow in the ME. This reduction was 4 times greater for the modified Jobe technique, and these findings have important implications for UCL reconstruction surgery. Clinical Relevance: As the rate of revision UCL reconstructions continues to rise, investigation into causes for failure of primary surgery is needed. One potential cause is poor tendon-to-bone healing due to inadequate vascularity. This study quantifies the amount of vascular insult that is incurred in the ME during UCL reconstruction. While vascular insult is only one of many factors that affects the surgical success rate, surgeons performing this procedure should be mindful of this potential for vascular disruption.