Sonographic findings for the common extensor tendon of the elbow in the general population.

OBJECTIVE: To describe structural characteristics and sonographic alterations of the common extensor tendon (CET).
METHODS: In 240 patients, we determined the body mass index; sonographic CET thickness, morphologic characteristics, and alterations; and color Doppler measurements of the epicondylar artery width and peak systolic velocity. Age, sex, epicondylalgia history, activities (work, sports, and hobbies), and dominant and nondominant elbows were noted.
RESULTS: The CET was thicker in the dominant elbow (4.77 versus 4.61 mm [P = .023]), male patients (dominant, 5.09 versus 4.46 mm [P < .001]; nondominant, 5.00 versus 4.21 mm [P < .001]), patients involved in risk activities (dominant, 5.21 versus 4.70 mm [P < .001]; nondominant, 5.12 versus 4.53 mm [P < .001]), and those with a history of epicondylalgia (right, 5.27 versus 4.70 mm [P < .001]; left, 4.86 versus 4.60 mm [P = .316]). Thickness correlated weakly with age (dominant, r = 0.284; nondominant, r = 0.215) and moderately with weight (dominant, r = 0.492; nondominant, r = 0.502). The mean epicondylar artery diameter was 1.35 mm (SD, 0.96 mm); mean peak velocity, 13.01 cm/s (SD, 4.90 cm/s). Morphologic abnormalities were found in 79.5% of patients with a history of epicondylalgia; 7.7% with no history had abnormalities; and 55.9% with abnormalities but no history were older than 55 years. Bone spurs (49.2% versus 16.4% [P < .001]), tendon calcifications (21.5% versus 3.9% [P < .001]), and bone cortex abnormalities (12.3% versus 1.7% [P < .001]) were found more often in non-normal elbows; 79.4% of bone spurs in normal elbows occurred in patients older than 55 years.
CONCLUSIONS: Mild sonographic alterations in the CET and bone spurs should be considered with caution when assessing epicondylar pain, especially in patients older than 55 years and those with a history of epicondylalgia.