Traumatic Brain Injury and Subsequent Musculoskeletal Injury Risk by Body Region

BACKGROUND AND AIM: Traumatic brain injuries (TBI) have been associated with increased risk of musculoskeletal (MSK) injuries, particularly lower extremity injuries as TBIs may influence gait and postural stability. This study evaluated the association across multiple body regions. METHODS: Incident TBI and MSK injuries were identified from accessible electronic medical records among active-duty U.S. Army Soldiers in 2016 through 2019. TBI was defined using International Classification of Diseases (ICD)-9 and -10 and Department of Defense codes. MSK injuries were grouped into body regions based on ICD-10 codes. Each Soldier with TBI (n=21,625) was matched with replacement to five Soldiers without TBI (n=108,125) on age, sex, and calendar month. Hazard ratios (HR) and 95% confidence intervals (CI) were calculated from Cox proportional hazards regression models stratified by matching factors and adjusted for race, education, rank, years of service, military occupational specialty, and history of deployment to combat countries. RESULTS:Soldiers were 30.3 (9.1) years old at the start of follow-up and predominantly male (87.3%) and White (69.8%). By the end of follow-up, there were 15,335 any MSK injuries in 10,965 person-years among Soldiers with TBI and 55,860 any MSK injuries in 104,396 person-years among Soldiers without TBI. Soldiers with TBI had significantly elevated rates of injury for any MSK [HR (95% CI): 2.33 (2.29, 2.37)], lower extremity [1.43 (1.39, 1.46)], upper extremity [2.00 (1.95, 2.06)], head/neck/cervical [4.16 (4.02, 4.30)], torso [3.44 (3.31, 3.59)], low back/pelvis [2.03 (1.98, 2.09)], spine [2.98 (2.83, 3.15)], and other [3.61 (3.43, 3.81)]. CONCLUSIONS:In addition to lower extremity injuries, TBI may increase MSK injuries risk in multiple other body regions. The mechanisms underlying how TBI could affect MSK injuries across the body should be evaluated. The views expressed are those of the authors and do not reflect the official policy of the Department of Army, Department of Defense, or the U.S. Government. KEYWORDS: Occupational epidemiology, occupational exposures, exposures