Tophaceous gout-related carpal tunnel syndrome and flexor tendon involvement: a systematic review

Background Tophaceous gout is an uncommon but clinically important cause of secondary carpal tunnel syndrome (CTS), with lesions ranging from diffuse flexor tenosynovitis to intratendinous destruction and direct median nerve involvement. Methods PubMed/MEDLINE, Scopus, and Web of Science Core Collection were searched through 23 July 2026, supplemented by Google Scholar, publisher-page verification, and citation searching. Human primary reports explicitly attributing CTS or wrist-level median neuropathy to gout, tophus, or monosodium urate deposition were eligible. Two reviewers independently screened records. Fifty-seven reports (27 complete/detailed and 30 limited clinical sources) formed the primary synthesis and underwent design-appropriate Joanna Briggs Institute appraisal; 12 bibliographic or translation-limited reports were retained as historical ancillary evidence. Primary reports were additionally classified post hoc by causal certainty. Results Of 478 database records, 302 unique records were screened, and 69 canonical reports were included. The 57-report primary synthesis comprised 44 case reports or clinical-image reports, 12 case series, and one nonrandomized comparative study, representing at least 120 patients, 152 CTS wrists, and 146 gout-attributable wrists. Sex was reportable for 117 patients, of whom 111 (94.9%) were male. Causal certainty was Tier 1 (direct local confirmation) in 41 reports, Tier 2 (anatomically supported) in 5, and Tier 3 (explicit report-level attribution) in 11. Post hoc sensitivity analyses retaining Tier 1 + 2 ( n = 46) and then Tier 1 only ( n = 41) did not change the principal qualitative interpretations. Open decompression with lesion treatment was the most frequently reported operative pattern, but evidence remained insufficient to determine a preferred tendon procedure. JBI findings are reported by design; 481 item-level judgments are retained only as an audit total. Conclusion Gout should be considered in atypical, acute, severe, recurrent, bilateral, or mass-associated CTS. In surgically treated reports, decompression was commonly combined with individualized management of tophaceous and tendon disease. The evidence is predominantly case-based and hypothesis-generating and is insufficient to define a validated treatment pathway or preferred tendon procedure.