Long-Term Career and Healthcare Impacts of Hip/Pelvic Bone Stress Injuries Sustained During Basic Combat Training: A Case-Control Study in Graduates

BACKGROUND: Hip and pelvic bone stress injuries (BSIs) represent a small but clinically significant subset of overuse injuries sustained during U.S. Army Basic Combat Training (BCT). However, the long-term military service and healthcare implications remain unclear. This study examined the impact of hip and pelvic BSIs sustained during BCT on subsequent military career outcomes and musculoskeletal healthcare utilization. METHODS: In this case-control study, BCT graduates from fiscal years 2015 to 2017 were analyzed. Cases included 895 BCT graduates with MRI-confirmed hip or pelvic BSI, representing 63.6% of all BSI-diagnosed trainees; controls (n=2,685) were BCT graduates without BSI, matched 3:1 by age and sex. Adjusted logistic regression models evaluated differences in Advanced Individual Training (AIT) graduation, service retention, and satisfactory completion of obligated service. Time-to-discharge was analyzed using Cox proportional hazards models, and annual musculoskeletal healthcare encounters were compared using negative binomial regression. RESULTS: Compared with controls, trainees with MRI-confirmed hip and pelvic BSIs had significantly worse career and healthcare outcomes. BSI cases had significantly lower odds of graduating from AIT (OR = 0.27, 95% CI: 0.18-0.41) and lower odds of satisfactory completion of obligated service (OR = 0.62, 95% CI: 0.48-0.79) compared to controls. BSI cases had a higher risk of early discharge (HR = 1.44, 95% CI: 1.30-1.60). Female cases demonstrated higher attrition and lower graduation rates than males. Musculoskeletal healthcare utilization was 2.6 times higher among BSI cases during the first post-BCT year (RR = 2.61, 95% CI: 2.31-2.96) and remained elevated through year three. CONCLUSIONS: Trainees who sustain hip or pelvic BSIs during BCT experience lasting negative impacts on military retention and healthcare utilization, despite successfully graduating from BCT. These injuries impose a disproportionate long-term burden, particularly among female trainees. Targeted prevention and comprehensive rehabilitation strategies are essential to mitigate their career and readiness impacts.