Abstract
Thoracic outlet syndrome results from neurovascular compression at the thoracic outlet, with the vascular subtype, often linked to cervical ribs leading to subclavian artery stenosis, aneurysm, or thromboembolism. Adson's test is a long-standing provocative maneuver used for diagnosis, but its accuracy has been questioned. This systematic review, conducted according to PRISMA 2020 guidelines, searched PubMed, Embase, Scopus, and the Cochrane Library up to August 2025. Studies were included if they involved more than 20 human participants, assessed Adson's test against imaging or surgical confirmation, and reported diagnostic accuracy outcomes. Risk of bias was evaluated with QUADAS-2 and the Cochrane tool. Out of 276 identified records, six studies with a total of 305 participants met the criteria. Reported sensitivity ranged from 72% to 92%, whereas specificity was consistently low (9-53%). False positives were frequent in healthy volunteers and in patients with overlapping disorders such as carpal tunnel syndrome, but predictive value improved in cases with cervical ribs or when combined with other maneuvers. Overall, Adson's test demonstrates relatively high sensitivity but poor specificity, limiting its use as a confirmatory diagnostic tool. Its clinical value lies primarily in initial screening and triage, especially in patients with anatomical anomalies such as cervical ribs, while modern imaging remains essential for definitive diagnosis and management.