Summary

There is a prognostic relationship of the MRI grade and tear location with the success of non-operative treatment for elbow UCL injuries in professional baseball players.

Abstract

Purpose

To evaluate the prognostic relationship of MRI grade and tear location with outcomes for professional baseball players treated non-operatively for their elbow UCL injuries.
 
Methods: After obtaining IRB and MLB approval, we identified 544 professional baseball players from the MLB Health and Injury Tracking System (HITS) treated non-operatively for their UCL injuries from 2011-2015. Of these players, 237 MRI’s were directly available for review by an independent, expert musculoskeletal radiologist who determined the grade (Grade I -edema, II-partial tear, III-complete tear) and location of the tear (humeral, ulnar, both-sided). Player demographics and outcomes including return to throwing (RTT), return to play (RTP), failed non-operative treatment leading to UCL reconstruction (UCLR), and Kaplan-Meier survivorship analysis of the native UCL to re-injury or surgery based on MRI grade and tear location was measured. A multivariate analysis adjusting for age, MRI grade, tear location, and league status (Major = MLB; Minor = MiLB) was also performed.
 
Results:  The average age of all players was 22.5 years, 10% played at the MLB level, and 84% were pitchers. The radiologist’s grading was distributed as follows: Grade I (36%), Grade II (49%), and Grade III (15%) injuries. The tear locations were humeral (65%), ulnar (13%), and both-sided (22%). There were no statistically significant differences in RTT, RTP, and UCLR by grade or tear location. However, objectively, ulnar-sided tears had the lowest RTT (81%) and RTP (42%) compared to other locations. Objectively, the ulnar (58%) and both-sided (60%) tears had a higher rate of UCLR compared to humeral sided tears (51%, p=0.441). The survivorship analysis showed a consistent decline over time with increasing MRI grade. By location, humeral tears had the highest survivorship (1 yr = 51%; 2 yr = 44%). However, there was no statistically significant differences for either grade or location in the survivorship analysis. Multivariate analysis determined the likelihood of not returning to play was 3 times higher [95% CI: 1-9.3; p=0.044] for older players (>25) compared to younger players. The likelihood of having re-injury or UCLR after non-operative treatment failed was almost 6 times higher [95% CI: 1.5-21.7; p=0.012] for MLB players as opposed to MiLB players. MRI grade and tear location were not significantly predictive of returning to play, re-injury, or surgery.
 

Conclusions

To date, this is the largest study to evaluate the prognostic relationship of MRI grade and tear location with the outcomes after non-operative treatment for elbow UCL tears in professional baseball players. Lower MRI grade and humeral location are objectively associated with a higher RTT, higher RTP, lower UCLR, and higher survival then with higher grade, ulnar sided, or both-sided tears in the non-operative treatment of UCL injuries. Older age (>25) had a significantly higher likelihood of not being able to RTP after non-operative treatment. Competing at the MLB level had a higher likelihood of re-injury or having UCLR. Based on this study, non-operative treatment of UCL injuries will likely be more successful in younger players, lower grade tears, and humeral-sided injuries.