Diagnostic accuracy of examination tests for lateral elbow tendinopathy (LET)-A systematic review

Background: Reviews on the diagnostic performance of the examination tests for lateral elbow tendinopa-thy (LET) based on updated context-specific tools and guidelines are missing.Purpose: To review the diagnostic accuracy of examination tests used in LET.Design: Systematic review following PRISMA-DTA guidelines. Methods: We searched MEDLINE, PubMed, CINAHL, EMBASE, PEDro, ScienceDirect, and Cochrane Library databases. The QUADAS-2 checklist was used to assess the methodological quality of the eligible studies. We included diagnostic studies reporting the accuracy of physical examination tests or imaging modalities used in patients with LET.Results: Twenty-four studies with 1370 participants were identified reporting the diagnostic performance of Ultrasound Imaging (USI) (18 studies), physical examination tests (2 studies) and Magnetic Resonance Imaging (MRI) (4 studies). Most studies (97%) were assessed with "unclear" or "high risk" of bias. So-noelastography showed the highest sensitivity (75-100%) and specificity (85-96%). Grayscale with or without Doppler USI presented poor to excellent values (sensitivity: 53%-10 0%, specificity: 42%-90%). MRI performed better in the diagnosis of tendon thickening and enthesopathy (sensitivity and specificity: 81%-100%). The Cozen's test reported high sensitivity (91%) while a grip strength difference of 5%-10% between elbow flexion and extension showed high sensitivity (78%-83%) and specificity (80%-90%).Conclusions: Cozen's test and grip strength measurement present high accuracy in the diagnosis of LET but are poorly investigated. USI and MRI provide variable diagnostic accuracy depending on the entities reported and should be recommended with caution when differential diagnosis is necessary. Substantial heterogeneity was found in inclusion criteria, operator/ examiner, mode of application, type of equipment and reference standards across the studies. Systematic review registration: PROSPERO ID CRD42020160402 (c) 2021 Elsevier Inc. All rights reserved.