Soft-tissue reconstruction timing in ballistic lower extremity open fractures: impact on osteomyelitis and union

Ballistic lower extremity open fractures represent a distinct subset of high-energy injuries characterized by extensive soft-tissue destruction, contamination, and complex wound biology. Although early soft-tissue reconstruction is widely advocated, a clinically relevant timing threshold specific to ballistic trauma remains unclear. This study aimed to evaluate the impact of soft-tissue reconstruction timing on osteomyelitis and bone union in ballistic lower extremity open fractures.

This retrospective cohort study included 56 adult male patients with high-energy ballistic lower extremity open fractures classified as Gustilo-Anderson type IIIB-IIIC, treated between 2016 and 2024. These injuries represent a severe form of extremity trauma, frequently encountered in military-related or complex trauma settings. Demographic characteristics, vascular injury, reconstruction timing, debridement burden, definitive fixation method, and clinical outcomes were recorded. Patients were stratified according to reconstruction timing. Receiver operating characteristic (ROC) analysis was performed to determine the optimal temporal threshold for predicting osteomyelitis, and logistic regression analysis was used to identify independent predictors.

Osteomyelitis developed in 23 patients (41.1%). ROC analysis identified 14.5 days as the optimal threshold for soft-tissue reconstruction (AUC 0.773), with reconstruction beyond this cutoff significantly increasing osteomyelitis risk (58.8% vs. 13.6%). Multivariable logistic regression analysis demonstrated that increasing time to soft-tissue reconstruction was independently associated with osteomyelitis risk (OR 1.043 per day, p = 0.011). Bone union was achieved in 75% of patients, and no significant association was observed between reconstruction timing and time to union. Prolonged union was instead associated with a greater number of pre-reconstruction debridements.

Delayed soft-tissue reconstruction beyond approximately two weeks may be associated with an increased risk of osteomyelitis in ballistic lower extremity open fractures. These findings suggest that earlier provision of vascularized coverage, following adequate serial debridement, can be beneficial, while highlighting the importance of considering wound biology rather than relying solely on fixed temporal thresholds. Bone healing, in contrast, appears to be more closely related to initial injury severity than to reconstruction timing.