Spinal Flexion Distraction Injuries: Chance Fractures and Posterior Ligamentous Equivalents in Children and Adolescents

Flexion-distraction injuries (FDI) are uncommon and often serious due to the mechanism of injury. Although originally described as a bony lesion in the thoracolumbar spine, these injuries can be purely bony, purely ligamentous/soft tissue or a combination at all spinal levels. Because of the forces involved, associated non-spine injuries can occur. Data on patients age 0-18 years with spinal injuries over a ten-year period were retrospectively reviewed and patients were classified into two groups, those with FDI and those with a spinal fracture other than FDI. Cervical and thoracic FDI, Chance fractures and posterior ligamentous equivalents, all considered FDI in this study, occurred in 22/301 spinal injured patients. The highest incidence considering all spinal injured patients was in the under 10 years old group (31.6%; p=0.004). A motor vehicle collision was the most common mechanism of injury. Statistically significant differences between patients with FDI compared to those without were respectively: average age (13.7 vs. 15.6 years), length of stay (10.2 days vs. 4.0 days), follow-up (1.7 years vs. 0.5 years), spinal surgery (78.3% vs. 15.5%), intra-abdominal organ injury (26% vs. 11%) and neurological deficit at presentation (43% vs. 10.4%) and at final follow-up (22% vs. 4%). Five patients without neurologic deficit did not undergo surgery.Seventy-two percent (13/18) of FDI patients having surgery required instrumentation. There was no association between injury level and FDI incidence or neurological deficit. FDI are most common in younger children with high likelihood of associated injuries, including intra-abdominal and neurological. FDI patients most often require surgical treatment, have an increased length of hospital stay and require longer-term follow-up.