Classification of proximal tibial fractures in children

Abstract

Purpose: To develop a classification system for all proximal tibial fractures in children that accounts for force of injury and fracture patterns.

Methods: At our institution, 135 pediatric proximal tibia fractures were treated from 1997 to 2005. Fractures were classified into four groups according to the direction of force of injury: valgus, varus, extension, and flexion-avulsion. Each group was subdivided into metaphyseal and physeal type by fracture location and Salter-Harris classification. Also included were tibial tuberosity and tibial spine fractures.

Results: Of the 135 fractures, 30 (22.2%) were classified as flexion group, 60 (44.4%) extension group, 28 (20.8%) valgus group, and 17 (12.6%) varus group. The most common type was extension-epiphyseal-intra-articular-tibial spine in 52 fractures (38.5%). This study shows that proximal tibial fractures are age-dependent in relation to: mechanism, location, and Salter-Harris type. In prepubescent children (ages 4-9 years), varus and valgus forces were the predominate mechanism of fracture creation. During the years nearing adolescence (around ages 10-12 years), a fracture mechanism involving extension forces predominated. With pubescence (after age 13 years), the flexion-avulsion pattern is most commonly seen. Furthermore, metaphyseal fractures predominated in the youngest population (ages 3-6 years), with tibial spine fractures occurring at age 10, Salter-Harris type I and II fractures at age 12, and Salter-Harris type III and IV physeal injuries occurring around age 14 years.

Conclusion: We propose a new classification scheme that reflects both the direction of force and fracture pattern that appears to be age-dependent. A better understanding of injury patterns based on the age of the child, in conjunction with appropriate pre-operative imaging studies, such as computer-aided tomography, will facilitate the operative treatment of these often complex fractures.

Fig. 1

Classification scheme for pediatric proximal tibial fractures

Fig. 2

The frequency of pediatric proximal tibial fractures classified using our system

Fig. 3

Age and gender distribution for extension injuries demonstrating an age-dependent relationship to fracture location and Salter–Harris type

Fig. 4

Distribution of varus/valgus sports-related injuries

Fig. 5

Trampoline jumping (often with multiple children on the trampoline) was the most common activity producing the greenstick valgus metaphyseal fracture

Fig. 6

Hyperextension injuries were commonly seen with the use of a bicycle, particularly when attempting to brake urgently with the ipsilateral foot striking the ground

Fig. 7

Flexion–avulsion injuries are most common in adolescent boys, particularly when attempting to push off for a jump in a sport such as basketball