Epidemiology and risk factors for premature physeal closure in distal femur fractures

BACKGROUND AND PURPOSE: Premature physeal closure (PPC) is a common and concerning complication to distal femoral fractures as the distal growth plate accounts for 70% of the growth of the femur. The literature is not unanimous in determining the risk factors of PPC, and the epidemiological characterization of these fractures is limited. Our aim was to calculate the population-based incidence and investigate risk factors for PPC in these fractures. PATIENTS AND METHODS: In this register-based study, between 2014 and 2021, 70 children with distal femoral physeal fractures presented to our hospital. Demographic data, and fracture- and treatment-related details were collected using the Kids’ Fracture Tool. A directed acyclic graph (DAG) was constructed to determine confounding factors used in the risk analysis. RESULTS: Physeal fractures of the distal femur occurred with an annual incidence of 6/10(5) children, and a resulting PPC occurred in 16/70 (23%) with an annual incidence of 1.3/10(5) children. In multivariable analysis, dislocation exceeding 10 mm was a risk factor for PPC (OR 6.3, CI 1.4-22). CONCLUSION: One-fourth of distal femoral physeal fractures developed PPC. Greater dislocation and higher injury energy were significant risk factors, whereas choice of fracture treatment was not an independent risk factor. All patients with PPC belonged in the age group 11–16 years.