Evidence of subclinical medial collateral ligament injury and posteromedial impingement in professional baseball players.

Background: Recognition and treatment of elbow conditions such as medial collateral ligament injury and posteromedial impingement are increasing in throwing athletes. Magnetic resonance imaging may provide pivotal information in the management of these athletes. Knowledge of the utility of magnetic resonance imaging has become widespread throughout the baseball community. However, data on the frequency and extent of asymptomatic magnetic resonance imaging findings in the elbows of this throwing population are lacking .

Hypothesis: Abnormalities in the throwing elbows of asymptomatic professional baseball players compared to the nonthrowing elbows are frequently seen in magnetic resonance images.

Study Design: Descriptive anatomical study.

Methods: Sixteen asymptomatic professional baseball players with no history of injury underwent bilateral elbow magnetic resonance imaging using a standardized sequencing protocol. The magnetic resonance images were reviewed, in a blinded fashion, by 2 musculoskeletal radiologists and 1 orthopaedic surgeon.

Results: Medial collateral ligament abnormalities (including thickening, signal heterogeneity, or discontinuity) were present in 87% of players' dominant elbows. Findings consistent with posteromedial impingement were present in 13 of 16 subjects. There was a significant correlation between medial collateral ligament thickening and posteromedial subchondral sclerosis (P = .04). The throwing elbow was correctly identified in all 16 subjects. No significant correlation between magnetic resonance imaging findings and age could be detected.

Conclusions: This study demonstrates a high rate of abnormal magnetic resonance imaging findings in asymptomatic throwers' elbows. These baseline findings must be considered when magnetic resonance imaging is being used as a factor in treatment decisions.