Common extensor tendon thickness measurements at the radiocapitellar region in diagnosis of lateral elbow tendinopathy

ateral elbow tendinopathy (LET) is a clinical entity known as “ten-nis elbow,” which presents with pain due to the overuse of the common extensor tendon (CET). LET has mistakenly been referred to as lateral epicondylitis (1). LET diagnosis is often made by physical examination on a clinical basis, and imaging is rarely needed; however, in cases where conservative treatment methods fail due to the advanced disease stage or the presence of additional pathologies, imaging may be needed to assess the level of impairment, plan treatment strategies, or guide surgery (2). Ultrasonography (US) is a valuable imaging method in LET. Gray-scale US and Doppler findings in LET have been previously described in de-tail (1–7). Some authors have argued for the diagnostic value of tendon thickness and area at the capitellar region over quantitative methods of diagnosis (5, 7). Yet, there are controversial topics related to the diag-nosis of LET, such as the presence of asymptomatic patients despite US findings of tendinosis (hypoechogenicity heterogeneity) (1, 4, 8). This decreases the specificity of qualitative US findings. Another controver-sial topic is the claim that the addition of Doppler findings increases the accuracy of diagnosis in chronic LET (4). Unfortunately, neovascu-larization, as identified by previous studies, is not a common finding in chronic tendinopathies (5) but is often reported in acute cases (9, 10). Finally, in a study that measured the capitellar tendon thickness/area, thickness/area and specificity increased, but sensitivity decreased (7). This suggests that a potential increase in false-negative cases is possible. Thus, in cases in which increased tendon thickness is not sufficient for assessment, the measurement of capitellar tendon thickness may not be of value. Therefore new criteria are needed to increase the accuracy of US. In light of the above-mentioned concerns, we aimed to study the overall combined accuracy and diagnostic value of qualitative US findings combined with capitellar and radiocapitellar tendon-thickness measurements in LET.