Magnetic resonance imaging evaluation of the ulnar collateral ligament in young baseball pitchers less than 18 years of age.
BACKGROUND
It has been shown that the asymptomatic, dominant elbow of professional baseball pitchers can demonstrate magnetic resonance (MR) imaging signal abnormalities of the ulnar collateral ligament (UCL) consistent with a strain. The purpose of this study was to determine if younger, asymptomatic, adolescent baseball pitchers exhibit similar signal abnormalities in the UCL.


METHODS
Magnetic resonance images of both elbows of 14 asymptomatic, young male baseball pitchers (ranging in age from 12 to 20 years) were performed on an outpatient basis using a 1.5-T Sigma MRI unit with a dedicated extremity coil to obtain T1 and T2 coronal and axial images which were subsequently evaluated by a musculoskeletal radiologist. Chronic tears of the UCL were suspected if the signal was attenuated or absent. Magnetic resonance images of the UCL were also evaluated for high-intensity signal or thinning. Morphologic changes such as complete tears, avulsions or thickening were identified. The images were classified into 4 grades from 0 to 3 depending on the degree of signal abnormality.


RESULTS
No discrete tears were found in any of the subjects. For the dominant pitching arm, 4 of 14 subjects had increased thickness of the ulnar collateral ligament, 3 of 14 demonstrated Grade 1 changes, and 11 of 14 demonstrated no abnormal signal within the ligament. No focal tears were present in any of the subjects. Contralateral elbows in 13 of 14 patients demonstrated Grade 0 signals with 1 patient demonstrating morphological thickening of the ligament without increased signal.


CONCLUSIONS
Signal abnormalities in the throwing elbow of asymptomatic, adolescent pitchers were uncommon. These pitchers may not have experienced sufficient pitching time to develop changes in the UCL.
Jazrawi
Laith M
LM
NYU-Hospital for Joint Diseases Department of Orthopaedic Surgery, 301 East 17th Street, Suite 1402, New York, New York 10003, USA.
Leibman
Matt
M
Mechlin
Mike
M
Yufit
Pavel
P
Ishak
Charbel
C
Schweitzer
Mark
M
Rokito
Andrew
A
D000293:Adolescent; D001265:Athletic Injuries / Q000473:pathology; D001484:Baseball / Q000293:injuries; D017885:Collateral Ligaments / Q000293:injuries* / Q000473:pathology*; D007839:Functional Laterality; D006801:Humans; D008279:Magnetic Resonance Imaging; D008297:Male; D014457:Ulna / Q000033:anatomy & histology / Q000473:pathology*; D000092464:Elbow Injuries