Surgery for trapeziometacarpal osteoarthritis in relation to cumulative occupational hand force requirements: a Danish nationwide cohort study.

OBJECTIVES

To evaluate if higher cumulative occupational hand force requirements are associated with higher risks of surgery for trapeziometacarpal osteoarthritis and with surgery earlier in life.

METHODS

The study was based on Danish national registers. Among all persons born in Denmark 1931 to 1990, we included those who had been employed for at least 5 years since 1991 by the end of 2000, or later when this employment criterion was reached, up until the end of 2016. Cumulative exposure estimates for 10-year time windows (force-years) were assessed by combining individual year-by-year information on occupational codes with an expert based hand-arm job exposure matrix. First-time events of surgery for trapeziometacarpal osteoarthritis 2001 to 2017 constituted the outcome. Surgery rates were analysed by a logistic regression technique equivalent to discrete survival analysis using a 1-year lag. We also calculated rate advancement periods.

RESULTS

A total of 2 860 448 persons contributed with around 48 million person-years of follow-up, during which 3977 cases appeared (821 among men and 3156 among women). Compared with <5 force-years, the adjusted OR (ORadj) for ≥5 to <10 force-years was 1.39 (95% CI 1.14 to 1.68) and for ≥10 to 30 force-years 1.47 (95% CI 1.26 to 1.71) among men and 1.64 (95% CI 1.50 to 1.78) and 1.29 (95% CI 1.16 to 1.43) among women. The sex combined ORadj were 1.59 (95% CI 1.47 to 1.72) and 1.36 (95% CI 1.25 to 1.48). Among the exposed, surgery was advanced by 3 to 7 years.

CONCLUSION

Medium/high cumulative hand force requirements were associated with elevated hazard rates of surgery for trapeziometacarpal osteoarthritis and advanced the time of surgery by several years.