Mild Traumatic Brain Injury and Subsequent Musculoskeletal Injury in US Service Members

Area of Science:

• Military medicine
• Neurology
• Orthopedics

Background:

• Mild traumatic brain injury (mTBI) is a known risk factor for musculoskeletal injuries (MSKI).
• The association between mTBI and subsequent MSKI in US service members (SMs) with extended follow-up requires further investigation.
• Understanding potential sex-based differences in this association is crucial.

Purpose of the Study:

• To determine the association between mTBI and the risk of subsequent MSKI in a large cohort of US SMs.
• To examine whether this association differs between male and female SMs over an extended follow-up period.

Main Methods:

• A cohort study design was employed, including SMs with mTBI and propensity score-matched controls from 2016-2020.
• Medical records were utilized to identify mTBI and MSKI events using ICD-10 codes.
• Cox proportional hazards and Aalen additive hazards models were used to analyze associations, with adjustments for demographic and military-relevant factors. Sex as a moderator was also tested.

Main Results:

• mTBI was significantly associated with an increased hazard of subsequent MSKI on both relative (HR=2.24) and absolute scales (258 additional events per 100,000 person-days).
• While female SMs exhibited a higher hazard of MSKI overall, the association between mTBI and MSKI did not significantly differ by sex (P interaction=0.37).
• Specific hazard ratios for mTBI associated with MSKI were 2.28 for females and 2.20 for males.

Conclusions:

• mTBI is linked to a substantially higher risk of subsequent MSKI in US SMs.
• The findings underscore the importance of considering MSKI risk in individuals with a history of mTBI.
• These results can aid in patient counseling regarding MSKI risk following mTBI, irrespective of sex.