Total knee arthroplasty for posttraumatic osteoarthritis in military personnel under age 50

United States military personnel frequently suffer knee injuries. The resulting progressive posttraumatic osteoarthritis (PTOA) causes significant disability in these young high‐demand patients for which total knee arthroplasty (TKA) is the only effective treatment of their pain and impairment. Yet the use of this option for treatment of PTOA has not been studied. This retrospective review identified 74 knees in 64 U.S. military personnel who underwent TKA at ≤50 years of age during an 8‐year period at a tertiary‐care, academic, military medical center. Fifty‐five knees (74.3%) experienced one or more prior ligamentous, meniscal, or chondral injuries prior to arthroplasty. Only one subject had a history of osteochondral intra‐articular fracture. The average at injury was 29.2 years (95%CI of ±2.50) with an average age at arthroplasty of 44.3 years (±1.11). The most common injury was anterior cruciate ligament rupture (n = 19) with a mean time to TKA of 23.1 (±10.54) and 18.8 years (±7.01) when concomitant meniscal pathology was noted. Nineteen patients were noted to have radiographic and symptomatic end‐stage osteoarthritis without a specified etiology at 41.4 years (±1.47) and underwent subsequent TKA. This is the first study to evaluate treatment of end‐stage PT OA in young people treated with TKA, finding that the incidence of PTOA as an indication for arthroplasty is significantly higher than among civilians. In this otherwise healthy, high‐demand patient population, the rate of OA progression following knee injury is accelerated and the long term implications can be career and life altering.