Incidence of joint replacement among active component service members, U.S. Armed Forces, 2004-2014.

In the U.S., joint replacements have become more common and the average age of individuals who undergo joint replacements has decreased. Joint replacements among active component service members increased 10.5% during 2004-2009, then 61.9% during 2009-2014. Knees and hips were the most frequently replaced joints among service members. During the surveillance period (and particularly after 2009), incidence rates increased in each age group of service members 30 years or older. Relative to their respective counterparts, rates of joint replacement overall--and of the hip and knee specifically--were higher among service members who were black, non-Hispanic; officers; and healthcare workers. One year after joint replacement, 18.2% had retired; 5.2% had been medically disqualified from service; 6.3% had otherwise left service; and 70.3% were still in service. By 2 years post-joint replacement, 30.2% had retired; 13.0% had been medically disqualified; 10.0% had otherwise left service; and 46.8% were still in service. Service members aged 30-44 years were the most likely to remain in service post-joint replacement. Given the increases in the frequency of joint replacement among younger service members, the number of service members who remain in service post-joint replacement may continue to increase.