Lower extremity physeal fractures and post-traumatic surgical deformities; National Trauma Data Bank and institutional cohorts

Background: Pediatric lower extremity physeal fractures carry a risk of developing deformities. Most epidemiological evidence is over 25 years old, single institution, and lacks follow-up, while recent studies report variable results. Understanding their epidemiology and deformity risk is important for patient counseling and follow-up. Methods: The National Trauma Data Bank (NTDB) from 2016 was queried to describe the modern epidemiology of physeal fractures. This was contrasted with our 10-year experience of surgically treated deformities. Basic descriptive statistics, Chi-square analysis, prevalence ratios and multivariable linear regression were used to interpret results. Results: The NTDB contained 22,048 non-physeal and 1,929 physeal fractures of the femur, tibia, and fibula. Physeal fracture prevalence rose after 8 years of age but decreased for girls 2 years sooner than boys. Salter Harris (SH) type 2 fractures predominated. Physeal fractures were more commonly associated with lower energy mechanisms of injury. Distal tibia fractures were more prevalent in the NTDB cohort, while distal femur and SH-1 fractures were more prevalent in the operative cohort. Over 10 years, only 52 (5.3%) of the deformity-correcting surgeries at our institution were for physeal fracture sequelae. Age at injury and intraarticular fractures were associated with shorter times from injury to deformity correction. Conclusion: Lower extremity physeal fractures are uncommon. Fracture pattern prevalence differs from an operative cohort. Proximal tibia physeal fractures appear to be an underappreciated source of deformity. The risk of developing deformity requiring operative intervention appears to be low and is generally treated within 2 years of initial injury.