Lateral epicondylitis clinically presents as focal tenderness at the lateral epicondyle with reduced strength with a resisted grip. The diagnosis is usually made on the basis of clinical examination; however, ultrasound (MSKUS) imaging may be used in cases refractory to therapy or when the diagnosis is uncertain.
With MSKUS, lateral epicondylitis appears as an outward-bowing, thickened tendon with a heterogeneous echotexture. Fluid may be noted between the tendon and the underlying lateral epicondyle. With power Doppler, hyperemia may be detected because of the angiofibroblastic reaction inside the tendon. Additional findings include irregularity of the osseous tendon attachment at the lateral epicondyle, calcification within the tendon, or small tears within the substance of the tendon > Spicer et al. 2019