Objective To assess temporal trends in carpal tunnel syndrome (CTS) incidence, surgical treatment and work-related lost time. Methods Incident CTS and first-time carpal tunnel release among Olmsted County, Minnesota, residents were identified using the medical records linkage system of the Rochester Epidemiology Project; 80% of a sample were confirmed by medical record review. Work-related CTS was identified from the Minnesota Department of Labor and Industry. Results Altogether, 10,069 Olmsted County residents were initially diagnosed with CTS in 1981-2005. Overall incidence (adjusted to the 2000 U.S. population) was 491 and 258 per 100,000 person-years for women versus men (p < 0.0001) and 376 per 100,000 for both sexes combined. Adjusted annual rates increased from 258 per 100,000 in 1981-1985 to 424 in 2000-2005 (p < 0.0001). The average annual incidence of carpal tunnel release surgery was 109 per 100,000, while that for work-related CTS was 11 per 100,000. An increase in young, working-age individuals seeking medical attention for symptoms of less severe CTS in the early to mid-1980s was followed in the 1990s by an increasing incidence in elderly people. Conclusions The incidence of medically-diagnosed CTS accelerated in the 1980s. The cause of the increase is unclear, but it corresponds to an epidemic of CTS cases resulting in lost work days that began in the mid-1980s and lasted through the mid-1990s. The elderly present with more severe disease and are more likely to have carpal tunnel surgery, which may have significant health policy implications given the aging population.

Background The aim of this study was to compare the effectiveness of ultrasound-guided injections to blind injections in the treatment of carpal tunnel syndrome (CTS) in a large community-based cohort. Methods This study evaluated residents of Olmsted County, MN, USA, treated with a corticosteroid injection for CTS between 2001 and 2010. The proportion of patients receiving retreatment and the duration of retreatment-free survival between blind and ultrasound-guided injections were compared. Propensity score matching was used to control for confounding by indication. Results In the matched dataset consisting of 234 (out of 600) hands treated with a blind injection and 87 (out of 89) ultrasound-guided injection cases, ultrasound guidance was associated with a reduced hazard of retreatment (hazard ratio, 0.59; 95% confidence interval [CI], 0.37 - 0.93). In addition, ultrasound guidance was associated with 55% reduced odds of retreatment within one year compared to blind injections (adjusted odds ratio, 0.45; 95% CI, 0.24 - 0.83). Conclusion This study indicates that ultrasound-guided injections are more effective in comparison to blind injections in the treatment of CTS.

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Introduction Corticosteroid injection is a recommended treatment option for carpal tunnel syndrome (CTS), before considering surgery. Nevertheless, the role of injections remains controversial since there is only strong evidence for short-term benefits. The purpose of this study was to determine the re-intervention rate and to identify prognostic indicators for subsequent treatment after a corticosteroid injection for CTS. Methods This study evaluated residents of Olmsted County, treated with a corticosteroid injection for CTS between 2001 and 2010. Failure of treatment was the primary outcome of interest. Two definitions for failure were examined: 1) patient receiving subsequent procedural intervention and 2) patient undergoing carpal tunnel release. Survival was estimated using Kaplan-Meier methods and association of covariates with increased failure was modeled using Cox proportional hazards regression. Results There were a total of 774 affected hands in 595 patients. The median follow-up period was 7.4 years. Re-intervention was performed in 68% of cases, of which 63% resulted in eventual surgery. Injectate volume was significant for the outcome of any retreatment (hazard ratio (HR) 0.879[0.804–0.96]) and surgery (HR 0.906[0.827–0.99]). Rheumatoid arthritis was also significant in both models, with HR 0.627[0.404–0.97] for any retreatment and HR 0.493[0.292–0.83] for surgery. Conclusions In this cohort, 32% of the patients did not receive subsequent treatment after a single injection, which indicates that there is a therapeutic role for corticosteroid injections in the treatment of CTS. Further research is necessary to identify those patients who will benefit from an injection, in order to provide more individually tailored treatment.