2. Examine differences in separation (EPTS, disability, overall attrition) for enlistees who entered military service via an approved waiver for shoulder, knee, or ankle injury compared to the medically qualified by sex.
3. Describe potential for refinement of accession medical waiver approval criteria and/or re-injury prevention strategies among enlistees who entered military service via an approved waiver for a shoulder, knee, or ankle injury.
Each year, the service medical waiver authorities consider over 5,000 enlisted accession waivers for a history of pre-service musculoskeletal issues including musculoskeletal injury (MSKI). However, little is known regarding the short- and long-term impact of pre-accession MSKIs on readiness, and whether the impact differs between male and female military enlistees. Utilizing Kaplan-Meier survival analysis, Chi-square tests, and risk ratios, we compared retention in the first year of service and disability discharge between Army, Navy, Marine Corps, and Air Force active duty enlistees who accessed via an approved MSKI medical waiver for shoulder, knee or ankle injuries from fiscal year 2018 to 2022 to a matched comparison group of medically qualified (MQ) enlistees, i.e. those not needing a pre-accession medical waiver. Overall, retention in the first year of service was similar between each MSKI-waived enlistee cohort and their matched comparison group for both males and females. Separation within the first 180 days due to a condition existing prior to service (EPTS) was not significantly elevated for any female MSKI-waived group, although incomplete EPTS data lessens our power to detect differences. Nevertheless, males with a knee injury waiver had a statistically significant (p=0.012) elevation in EPTS separations. Females with a knee injury waiver were over five times more likely to receive a disability discharge by end of the study period (September, 2023) than MQ females. Males with shoulder and knee waivers were respectively 99% and 82% more likely to receive disability discharges compared to MQ males. This study suggests that while females and males with a pre-accession MSKI waiver are not at elevated risk for early separation, there is some potential long-term impact on disability discharge risk with differences observed between male and female enlistees. These findings highlight that although MSKI waiver approval criteria have minimal impact on short-term retainability for both males and females, history of a MSKI waiver was associated with elevated risk of early disability discharge, particularly among females. If this association persists longer term, then sex-specific prevention strategies to mitigate re-injury risk within this population should be considered to reduce the risk of disability discharge. Disclaimer: Material was reviewed by WRAIR. There is no objection to presentation. Opinions or assertions are private views of the authors and are not to be construed as official, or as reflecting true views of the Department of the Army or the Department of Defense. Investigators adhered to policies for protection of human subjects as prescribed in AR 70–25.