Carpal Tunnel Syndrome in Military Aviators.

Abstract

The incidence of carpal tunnel syndrome (CTS) is increased in occupations exposed to repetitive motion, poor wrist posture, and vibration exposure. While all pilots are exposed to these factors, helicopter pilots are especially exposed to vibration. The study is to identify the incidence and risk factors for CTS in military aviators. Clearance was obtained from Tripler Army Medical Center IRB. The Defense Medical Epidemiological Database was queried for all new cases of CTS from 2006 to 2015. Incidence rates (IRs) were determined for helicopter pilots, fixed-wing pilots, and nonpilot officers. Poisson regression analysis was used to calculate adjusted IR in order to control for demographic factors. Race was also taken into account, where pilots would classify themselves into a white or non-white race, defined by each individual. Race was assessed in the study to see if there were any differences in IR of CTS between white and non-white pilots. We identified 7,398 new cases of CTS among 2,319,352 person-years within the study period. Increasing age, female gender, and non-white race were significantly correlated with higher IR. Fixed-wing pilots demonstrated significantly lower adjusted IR than nonpilot officers in each age group. Helicopter pilots demonstrated higher IR than fixed-wing pilots in each age group. Helicopter pilots had lower incidence of CTS early in their career compared to nonpilot officers, but by age 40+, their IR ratio was significantly higher (1.21). Analysis of the database indicates that fixed-wing pilot status is a protective factor against development of CTS among U.S. military officers. In contrast, helicopter pilots were found to be at an increased rate of CTS than their fixed-wing counterparts. Their incidence is comparable to their nonpilot officer peers early in their career, but is significantly increased at the senior level. Increasing age and female gender are risk factors in the military officer population as expected. Non-white race was found to increase risk in the military population, in contrast to reports of the civilian population.