Abstract
Objectives:
The medial ulnar collateral ligament (MUCL) is the primary stabilizer of valgus forces across the elbow. Injury to the MUCL has a large impact on the throwing athlete, particularly in baseball. The incidence of MUCL injury in baseball pitchers is on the rise. Surgical treatment and rehabilitation is evolving to improve outcomes and improve return to sport time frames. The purpose of this study was to highlight the trends in MUCL repair and reconstruction in professional baseball pitchers, describe relevant outcomes such as return to any level of play (RTP) for surgical repair and reconstruction, and distinguish what factors might impact these outcomes. The authors hypothesize that primary and revision MUCL surgery is increasing with revision surgery requiring the greatest time to RTP.
Methods:
The Major League Baseball (MLB) Health and Injury Tracking System (MLB HITS) database was used to procure data during the targeted study period (2010 – 2023). All professional pitchers who underwent MUCL surgery within the study period were included. Variables analyzed included age, career length, and level of play. Surgical variables included date and type of procedure, RTP status, time required to RTP, return to same level of play (RTSL), career length before and after surgery, number of revision surgeries, and time between surgeries. Successful RTP was designated if a pitcher had returned in at least one professional game after index surgery. Analyses of trends over time were performed. The year 2020 was considered an outlier and omitted from the analysis of trends due to the coronavirus pandemic which limited games played.
Results:
A total of 2,287 pitchers underwent MUCL surgery during the study period (Table 1). The annual number of MUCL surgeries on all pitchers increased year over year (R2 = 0.821, p < 0.001), as did the annual number of reconstructions with internal brace (IB) augmentation (R2 = 0.896, p < 0.001) (Figure 1). The RTP rate (93%) for MLB pitchers was significantly higher compared to the RTSL rate (71%, P < 0.001). This difference was not observed in Minor League Baseball (MiLB) (RTP 76% vs. RTSL 74%, P = 0.142) (Figure 2). The percentage of players who RTP after revision surgery was significantly lower compared to primary surgery (71%vs. 80% respectively, P = 0.020). Mean time to RTP is significantly shorter (470 ± 135 days) compared to the mean time to RTSL (499 ± 153 days, P < 0.001) (Figure 3). The annual number of revision MUCL surgeries on all pitchers increased year over year as well (R2 = 0.322, p = 0.043).
Conclusions:
MUCL surgery continues to increase, also leading to increasing numbers of revisions in professional pitchers. Overall, 80% of pitchers were able to RTP at a mean of 470 days (15.5 months), while only 71% were able to RTSL at a mean of 499 days (16.5 months), but this varied based on level of play. Surgical techniques continue to evolve as MUCL repairs and reconstructions with IB augmentation have increased significantly in recent years. This study will help guide athlete expectations and surgeon decision-making.
