Macrotraumatic fractures of the multisegmented ankle-foot complex in military tactical athletes: A cohort study

Presented at the Society of Military Orthopaedic Surgeons 64th Annual Meeting, Dec 2022, Scottsdale, AZ Introduction: Injuries of the lower leg, ankle, and foot (collectively referred to as the ankle-foot complex) are ubiquitous in tactical athletes and are ranked in the top 10 diagnoses for healthcare burden in the Military Health System. It is therefore prudent to study the factors associated with these injuries, so that targeted risk mitigation strategies and anticipated medical services can be planned and employed both prior to and following injury. While there are few studies to the authors’ knowledge that have assessed the burden of macrotraumatic fractures of the ankle-foot complex in military tactical-athletes, no studies to date have specifically assessed ankle-foot fractures in the functional segments of the ankle-foot complex while considering sex, military occupation, rank, and year of injury. Therefore, the purpose of this retrospective cohort study was to characterize the incidence of macrotraumatic fractures of the tibia-fibula, rearfoot and forefoot in military tactical athletes, with consideration of these aforementioned factors. Methods: A population-based retrospective study of all service members in the US military was performed assessing the factors of sex, occupation, service branch, rank, and year on segmental tibia-fibula, rearfoot, and forefoot fracture incidence between 2006 and 2015. The Defense Medical Epidemiology Database was queried for the number of distinct patients with a primary diagnosis of fracture of the tibia-fibula (ICD-9 codes 823 [tibia and fibula fracture] and 824 [ankle fracture]), rearfoot (ICD-9 codes 825.0 [calcaneus fracture, closed], 825.1 [calcaneus fracture, open], 825.21 [talus fracture, closed], and 825.31 [talus fracture, open]), and forefoot (ICD-9 codes 825.2 [other tarsal and metatarsal bones, closed] and 825.3 codes [other tarsal and metatarsal bones, open] with talar fracture codes expunged) on the initial medical encounter. In the three-segment stratification, fractures of the midfoot were counted in the forefoot segment. Patients with repeat visits for the same diagnosis were only counted once in all analyses. A negative binomial regression assessed the adjusted factors of sex, branch, rank, and year. Results: In the adjusted analysis, female sex was found to only be a significant factor in forefoot fractures (RR=1.54), with females having a significantly higher risk. There were no significant se