Ulnar Collateral Ligament and Elbow Adaptations in High School Baseball Pitchers.
BACKGROUND
Baseball pitchers have adaptive changes in the soft tissues of the throwing elbow.


OBJECTIVE
High school baseball pitchers would show adaptive changes in the ulnar collateral ligament (UCL), such as calcifications and hypoechoic foci, thickening, and increased ulnohumeral joint laxity, on dynamic ultrasound (DUS).


METHODS
Cross-sectional study.


METHODS
Level 3.


METHODS
Twenty-two asymptomatic high school pitchers, designated as their primary position by their coach, underwent DUS and physical examination of the throwing and nonthrowing elbows prior to the start of the season. UCL substance consistency and thickness, ulnohumeral joint space widening, and soft tissue elbow structures were evaluated.


RESULTS
The mean age of the cohort was 16.9 years. Calcifications of the UCL were similar, being present in 7 of 22 (32%) throwing elbows versus 8 of 22 (36%) nonthrowing elbows (P = 0.11). UCL hypoechoic foci also were similar between elbows: 2 of 22 (9%) throwing elbows versus 0 of 22 nonthrowing elbows (P = 0.11). UCL thickness was also found to be similar in both elbows (throwing arm, 6.54 mm vs nonthrowing, 6.71 mm; P = 0.48). Ulnohumeral joint laxity unloaded (throwing arm, 3.13 mm vs nonthrowing, 3.17 mm; P = 0.835) and loaded (throwing arm, 3.87 mm vs nonthrowing arm, 4.11 mm; P = 0.30) was similar between elbows. Throwing elbows showed posteromedial olecranon spurring in 36%, effusions in 27%, and synovitis in 9%.


CONCLUSIONS
High school pitchers show limited adaptive changes in the elbow, including UCL calcifications, hypoechoic foci, posteromedial olecranon spurring, and effusions. However, these changes are similar to those seen in the nonthrowing elbow, and these younger athletes lack findings seen in professional and collegiate pitchers such as UCL thickening and increased ulnohumeral joint space laxity.


CONCLUSIONS
Preseason ultrasound examination of the high school pitching elbow lacks the adaptive changes to the elbow as seen in professional pitchers. These changes likely occur later in a pitcher's career.
Department of Orthopedics, Henry Ford Hospital, Detroit, Michigan nmarsha2@hfhs.org.
Nathan E
NE
Marshall
Department of Orthopedics, Henry Ford Hospital, Detroit, Michigan.
Robert A
RA
Keller
Department of Radiology, Henry Ford Hospital, Detroit, Michigan.
Marnix
M
Van Holsbeeck
Department of Orthopedics, Henry Ford Hospital, Detroit, Michigan.
Vasilios
V
Moutzouros
D000222:Adaptation, Physiological; D000293:Adolescent; D001132:Arm / Q000502:physiology; D001484:Baseball / Q000502:physiology*; D002114:Calcinosis / Q000000981:diagnostic imaging; D017885:Collateral Ligaments / Q000000981:diagnostic imaging* / Q000502:physiology*; D003430:Cross-Sectional Studies; D004550:Elbow / Q000000981:diagnostic imaging* / Q000502:physiology*; D006801:Humans; D007593:Joint Instability / Q000000981:diagnostic imaging; D008297:Male; D016059:Range of Motion, Articular; D012399:Rotation; D012782:Shoulder / Q000502:physiology; D014463:Ultrasonography
baseball; pitcher; throwing injury; ulnar collateral ligament