Three-Tesla MR imaging of the elbow in non-symptomatic professional baseball pitchers

Objectives: To retrospectively evaluate the qualitative and quantitative 3-T MR imaging features of the elbow in non-symptomatic professional baseball pitchers presenting as major league draft picks or trades.

Materials and methods: The Institutional Review Board (IRB) approved the HIPPA-compliant study. Informed consent was waived. Twenty-one professional non-symptomatic baseball pitchers (mean age 23, range 18 to 34 years old) underwent 3-T MR imaging of the pitching elbow. Two experienced readers independently performed qualitative (collateral ligaments, tendons, cartilage, bones, ulnar nerve, olecranon fossa, and joint fluid) and quantitative (collateral ligaments and posteromedial plica) evaluation. Descriptive statistics were calculated.

Results: Collateral ligament thickening was seen in a high proportion, nearly half, however, without features of full thickness tearing. Tendinosis without tearing was seen in 19 % (4/21) of common extensors. Cartilage abnormalities were infrequent. Bone abnormalities manifested as edema in 24 % (5/21) and humeroulnar osteophytosis. Ulnar nerve signal and/or morphologic abnormalities were seen in a very high proportion, up to 81 % (17/21). The olceranon fat pad showed scarring features in about one third. The median ligament thicknesses in mm measured: 4.6 UCL anterior bundle, 1.8 UCL posterior bundle, 1.9 RCL, 2.5 LUCL, and 0.7 mm anular. The median plica dimensions were 5.3 by 2.2 by 2.7 mm.

Conclusion: High-resolution 3-T MR imaging frequently shows abnormalities involving the ligaments, tendons, nerves, olecranon fat pad, and bones in non-symptomatic baseball pitchers.