Shoulder Injuries in Professional Baseball Batters: Analysis of 3,414 Injuries Over an 8-Year Period.

Purpose: To characterize the shoulder injuries experienced by baseball batters and position players (nonpitchers); to quantify the outcomes of these injuries with respect to time out of play, recurrence, and surgery rates; and to identify any injury patterns that are associated with worse outcomes.

Methods: Between 2011 and 2017, all Major League Baseball (MLB) and Minor League Baseball (MiLB) players who sustained shoulder injuries were identified using the MLB Health and Injury Tracking System (HITS). Injuries were included if they were sustained during baseball activity, resulted in at least 1 day missed (DM), and occurred in position players (nonpitchers).

Results: Over the study period, a total of 3,414 shoulder injuries occurred in batters, resulting in a sum of 68,808 DM and a mean of 22 DM per injury. Most injuries were a result of acute trauma (n = 2125; 62.2%) with throwing as the predominant activity (n = 1292; 38%). Rotator cuff strain/tears was the most common diagnosis (n = 790; 23.1%), and SLAP tears had the highest season-ending rate (35.3%) and need for surgery (45.1%). There was a lower frequency of surgery (6.2% vs 9.2%;  = .002) and reinjury (2.03% vs 3.62%;  = .007) in the throwing shoulder vs the nonthrowing shoulder. There was an increased frequency of surgery for the front versus the back batting shoulder (8.2% vs 6.2%;  = .031) with similar DM (20.7 vs 22.2;  = .333) and return to play rates (94.0% vs 92.2%;  = .135).

Conclusions: During the 7-season study period, there were a total of 3,414 shoulder injuries that resulted in nearly 70,000 days of out of play in professional baseball position players/batters (nonpitchers). Although pitchers were intentionally excluded from the analysis, throwing was still the most common mechanism of injury, and rotator cuff injuries were the most common injury. Labral tears were the most likely injury to be season ending and require surgery.

Clinical Relevance: This study is meant to help determine characteristics of shoulder injuries that occur in non-pitchers by focusing on professional baseball batters and position players. This information could be helpful to sports medicine practitioners and shoulder specialists to better prognosticate injury recovery.