THE EPIDEMIOLOGY OF TIBIAL SPINE FRACTURES IN CHILDREN: A MULTICENTER INVESTIGATION

BACKGROUND: Tibial spine fractures (TSFs) are intra-articular avulsion fractures of the intercondylar eminence which tend to afflict younger, skeletally immature patients. Given the relatively rare nature of these injuries, the epidemiology is not well-understood. There have been several estimates reported from single centers, though the potential for historical and regional variability in activities and risk factors limits the generalizability of their findings. Thus, the aim of the present investigation was to characterize the epidemiology of TSFs using pooled multicenter data. HYPOTHESIS/PURPOSE: Report on the epidemiology of tibial spine fractures. METHODS: This study was a retrospective analysis of patients with TSFs who were evaluated and treated at one of ten different sites across the United States. Information regarding patient demographics, injury mechanism, and imaging reports were collected. Fractures were classified according to the modified Meyers and McKeever method which groups the injuries as non-displaced (Type I), minimally displaced with an intact hinge (Type II), completely displaced (Type III), or completely displaced and comminuted (Type IV). Descriptive analyses were performed to evaluate the epidemiology of these fractures across the country. RESULTS: We identified 469 patients (69% male; mean age 12.1 + 2.9 years) with TSFs over an eight-year period. 73% of patients were 14 years or younger. With respect to fracture severity, 5% of patients were Meyers and McKeever Type I, 35% Type II, and 50% Type III, and 10% Type IV. Overall, 60% of the fractures were completely displaced (Types III and IV). The most common mechanism of injury was a contact injury (48%), while 46% reported a non-contact twisting injury. With regard to activity at the time of injury, over half (53%) of patients were involved in sports and 14% of patients were biking recreationally. Less common causes included a fall from height (9%), motor vehicle accident (4%) recreational running (3%), and horseplay (3%). Of those injured playing sports, football (35%), skiing (21%), basketball (10%), and soccer (10%) accounted for almost 80% of the injuries in this cohort. CONCLUSION: Ultimately, our study represents the first multicenter analysis of the epidemiology of tibial spine fractures. The patient demographics and mechanism of injury for these injuries appears relatively consistent across geographic distributions. However, the recent rise in youth sports participation, single sport specialization, and year-round play in pediatric athletes appears to have generated a new principal risk factor for this injury in sports participation as opposed to the historically-described biking accidents.