Association Between Lower-Limb Fractures and Carpal Tunnel Syndrome: A Nationwide Population-Based Cohort Study

Background: Lower-limb fractures often require prolonged use of assistive devices, which may increase mechanical stress on the upper extremities. However, the association between lower-limb fractures and subsequent carpal tunnel syndrome (CTS) remains unclear. Methods: This nationwide population-based cohort study used Taiwan's National Health Insurance Research Database (2011-2019) to identify 10,140 patients with lower-limb fractures and 10,140 propensity score-matched controls. Cox regression analysis estimated CTS risk after adjusting for demographics and comorbidities. Results: Patients with lower-limb fractures demonstrated increased CTS risk compared to controls (adjusted hazard ratio [HR] = 1.12, 95% confidence interval [CI]: 1.003-1.26; p = 0.044), with stronger associations in males (HR = 1.28, 95% CI: 1.05-1.55) and younger adults aged 20-65 years (HR = 1.19, 95% CI: 1.03-1.38). Conclusions: Lower-limb fractures are associated with modestly increased CTS risk, particularly in males and younger patients. Though biologically plausible, this observational study cannot establish causality. Heightened clinical awareness may be warranted, though prospective validation is needed.