Epidemiology and risk factors for loss to follow-up following operatively treated femur ballistic fractures

Introduction: Evidence regarding recommendations for treatment of ballistic fractures remains limited. This paucity of literature has largely been attributed to gunshot wound victims being a difficult population to study secondary to loss to follow-up. The purpose of this study was to examine the epidemiology of operatively treated ballistic femur fractures at our institution, the frequency of outpatient follow-up and risk factors for loss to follow-up. Methods: Inpatient consults from 2013-2018 were queried for femoral gunshot wounds treated operatively. Cases without internal or external fixation were excluded from the study. Postoperative visits where a patient was hospitalized or had expired were excluded from the analysis. Demographic information, length of hospital stay, and operative characteristics were compared for different fixation methods and examined as risk factors for loss to follow-up. Results: A total of 194 patients met inclusion criteria. The average age was 27 years old and 94% of the patients were male. Patient's stayed a median of 5 days post-operatively with patients treated with external fixation staying longer than internal fixation (14 days vs 5 days p=0.01). 9.3% of ballistic fractures had a concomitant vascular injury necessitating repair. 70.4% of patients attended their 2-week postoperative visit, 55.7% of patients attended their 6 week follow-up visit and 31.3% attended their 3 month follow-up visit. Risk factors for loss to follow-up at 3 month visit included younger age (p=0.028), decreased hospital length of stay (p=0.025) and intramedullary fixation (p=0.00015). Discussion and conclusion: This study reinforces the difficulty of studying ballistic fractures secondary to loss to follow-up. Younger age, shorter hospital stays and intramedullary fixation increased the risk for loss to follow-up at 3 months.