Complications in Thoracolumbar Spine Trauma

Injury Patterns

Understanding the injury patterns and pathologic forces leading to the injury is crucial to preventing complications. Overall, pediatric thoracolumbar injuries tend to occur in the older age group (>8 years old) compared to cervical injuries, which are more common in children younger than 8 years of age. Thoracolumbar fractures occur more frequently in males. Flexion is the most common mechanism of injury, which may have additional compression or distraction components. Consequently, compression fractures represent the most commonly reported thoracolumbar fractures in children. In pure compression injuries, posterior elements remain intact, and the loss of vertebral height is less than 30%. Depending on the severity of the axial loads, contiguous vertebral levels may be involved. Magnetic resonance imaging (MRI) is useful to rule out posterior ligamentous complex (PLC) injuries when there is more than 50% vertebral height loss. Regardless of the vertebral height loss and the number of involved vertebrae, neurological compromise is rare in compression fractures. Treatment is directed toward pain management, activity modification, and early return to activities. A thoracolumbosacral (TLSO) brace is typically worn for 6 to 8 weeks, with an excellent long-term outcome. Treatment is directed by the patient’s symptoms, and a single-level compression fracture may not require a brace. The lost vertebral height is commonly restored in children, owing to the remodeling potential of the growing spine. Bracing has not been found to influence the long-term outcomes of compression fractures or the remodeling potential of the vertebrae, although it may be beneficial in pain management.

With higher-energy axial loads, the vertebral disc is driven into the body, causing a fracture of the anterior and middle columns. Burst fractures are more common in the thoracolumbar junction (T10–L2) and are more likely to cause neurologic injury. Burst fractures with minimal deformity and no neurologic injury are stable, whereas focal kyphosis greater than 30 degrees, PLC disruption, neurologic injury, significant retropulsion (>50%), and significant vertebral height loss are indicators of instability. Stable burst fractures without neurologic injury are treated with activity modification and hyperextension TLSO for 8 to 12 weeks, while unstable fractures are commonly treated surgically.

Flexion-distraction injuries result in a three-column failure of the spinal column, commonly referred to as seatbelt injuries or chance fractures, in which the posterior elements fail in distraction, and the anterior column fails in compression. Chance fractures are a typical presentation of flexion-distraction injuries, and may be purely osseous, purely ligamentous, or, more commonly, a combination of osseous and ligamentous injuries. Flexion-distraction injuries are strongly associated with intra-abdominal and other spinal injuries, with up to 50% of children with seatbelt injuries reported to have spinal cord or visceral injuries. Chance fractures may go undiagnosed in the acute stage due to other life-threatening injuries requiring treatment, and a high degree of suspicion is required in patients with seatbelt injuries and other concomitant injuries. Furthermore, misdiagnosis of chance fractures is also common. Andras et al. reviewed 26 pediatric patients with flexion injuries to the spine and found that five out of seven (71%) chance fractures were misdiagnosed as compression fractures by a neurosurgeon or an orthopedic surgeon. They also found a 3-month delay from injury to proper treatment (in the form of posterior spinal fusion) in these patients. Chance fractures are typically treated surgically, although pure osseous injuries may be amenable to hyperextension TLSO or casting.

Other patterns of thoracolumbar injuries include fracture-dislocations and process fractures. Fracture-dislocations of the thoracolumbar spine are exceedingly rare in children, but may be the result of severe blunt trauma or fall from a significant height. Fracture-dislocations are typically associated with neurological injuries in the form of conus medullaris or cauda equina syndrome and require surgical stabilization and decompression. Fractures of the spinous or transverse processes are also the result of blunt trauma to the thoracolumbar spine but are rarely associated with visceral or spinal cord injuries. Process fractures are inherently stable and can be managed with pain control and activity modification. Facture-dislocations and process fractures are uncommon in children and should raise suspicion for nonaccidental trauma (NAT). Kemp et al. systematically reviewed the reported radiographic characteristics of NAT in the pediatric spine and found 12 cases of thoracolumbar spine injuries with a mean age of 13.5 months. Eleven (92%) cases had a fracture-dislocation in the thoracolumbar junction, and while 6 out of 12 patients had signs of neurological involvement, the clinical diagnosis was missed in 8 out of 12 cases. A thorough clinical evaluation, skeletal survey, and early involvement of child abuse and neglect teams is imperative to diagnose and treat NAT thoracolumbar injuries, prevent complications, and ensure the safety of the victims of child abuse.