Diagnostic Accuracy of Ultrasonography in Lateral Epicondyle Tendinopathy: A Systematic Review

Abstract

Introduction: Lateral Epicondyle Tendinopathy (LET), or 'Tennis Elbow', is a common musculoskeletal condition affecting athletes and individuals engaging in repetitive movements of the common extensor tendon (CET). Ultrasonography (US) is a popular, cost-effective and non-invasive imaging modality to assess the elbow for LET. Several characteristic US findings have been reported, but there is no established consensus for which are best diagnostic for LET. We systematically reviewed the published literature for the diagnostic accuracy (sensitivity and specificity) of US for LET. Methods: The PubMed database was searched systematically to identify relevant articles published from inception to 29th June 2026. The inclusion criteria involved studies investigating the diagnostic accuracy of US findings in LET against a reference standard, e.g. clinical examination or magnetic resonance imaging (MRI). Excluded studies were those lacking diagnostic outcome data or those combining imaging modalities in calculating diagnostic accuracy. Sensitivities and specificities were extracted from the studies. Results: In total, 147 records were identified and 11 studies were included in this review following screening (Figure 1). Tendon thickening of ≥ 4.85 mm demonstrated the highest sensitivity (90.5%), whilst ≥ 4.2 mm was the most specific (95.2%). Neovascularisation assessment via colour Doppler demonstrated superior sensitivities (57–95%) and specificities (88–100%) when compared to power Doppler. When assessing tendon elasticity, shear-wave elastosonography (SWE) and grey-scale US displayed superior sensitivities (90.5–100% and 95% respectively) compared to compression sonoelastography (SEL). However, all three US techniques confirmed elasticity changes are highly specific for LET. Conclusion: The US findings of tendon thickening, neovascularisation and tendon elasticity changes have high sensitivities and specificities for LET. Other signs, such as cortical irregularities and tendon tears, varied in their diagnostic accuracies. However, these characteristic US findings, alongside a patient history and clinical examination, can prove useful in the overall diagnostic context of LET.