Can the interpedicular distance reliably assess the severity of thoracolumbar burst fractures?

Study Design: Retrospective analysis of 260 patients with acute spine fractures treated at a tertiary trauma center from 1989 to 2009.

Objective: To correlate the Interpedicular distance (IPD) to the percentage of narrowing of the spinal canal and to the presence of neurological deficit and laminar fracture in thoracolumbar burst fractures.

Summary Of Background Data: Several reports use radiographic findings such as severity of vertebrae collapse, comminution of the vertebral body, and grade of localized kyphosis to determine the severity of spinal traumas and establish appropriate management. However, the importance of the IPD in burst fractures has rarely been mentioned, and no report specifically describes the correlation between an increased IPD and the severity of the lesion or a higher occurrence of lamina fractures.

Methods: Plain radiographs of 260 patients with acute thoracolumbar burst fractures were studied. The percentage of widening between the pedicles of the fractured vertebra (IPD) was established by comparing this distance with that of the vertebrae immediately above and below. Data concerning neurological status, percentage of narrowing of the spinal canal, and the presence of laminar fracture were correlated to the IPD.

Results: A significant correlation between IPD and the percentage of narrowing of the spinal canal was found (r = 0.39; t = 6.78; P = 0.00). IPD was significantly increased in patients with neurological deficit (24.7% ± 12.6%) and in patients with lamina fractures (24.6% ± 16.2%).

Conclusion: IPD measured from plain radiographs proved to be a reliable instrument to assess narrowing of the spinal canal, neurological deficits, and laminar fractures.