Musculoskeletal ultrasound (MSUS) imaging is used to investigate features of tendinosis. Recent studies have reported tendon pathology in not only the symptomatic tendon but also the contralateral asymptomatic tendon of animals and humans with unilateral Achilles tendinopathy. This study assessed the symptomatic and contralateral asymptomatic tendon in unilateral lateral epicondylalgia (LE) for features of tendinosis and compared with a pain-free control.
Twenty-nine participants with clinically diagnosed unilateral LE and 32 pain-free controls (matched for age, sex, and arm dominance) underwent a blinded bilateral musculoskeletal ultrasound examination of the common extensor tendon, using a standardised protocol. Greyscale features, including tendon thickening, hypoechoic region, fibrillar disruption and calcification, as well as neovascularity were scored using separate ordinal scales. Tendon thickness and hypoechoic volume were also measured.
The contralateral asymptomatic tendon did not differ from the tendons of the pain-free controls. The symptomatic tendon of LE participants revealed a significantly greater score for; tendon thickening (Mean difference: 0.76 [95% CI 0.22 to 1.30]), hypoechoic changes (0.58 [0.05 to 1.11]), fibrillar disruption (0.97 [0.52 to 1.42]), and neovascularity (1.53 [0.9 to 2.2]) than controls. Hypoechoic volume was greater in the symptomatic arm (33.0 mm [8.4 to 57.6]), than controls.
Unlike Achilles tendinopathy, musculoskeletal ultrasound examination did not reveal features of tendinosis in the contralateral asymptomatic limb beyond those present in tendons of pain-free controls.