Predictable Factors for Dural Tears in Lumbar Burst Fractures with Vertical Laminar Fractures

OBJECTIVE: The purpose of the present study was to determine the incidence of dural tears and predictable factors suggesting dural tears in patients who had lumbar burst fractures with vertical laminar fractures. METHODS: A retrospective review was done on thirty-one patients who underwent operative treatment for lumbar burst fractures with vertical laminar fractures between January 2003 and December 2008. All patients were divided into two groups according to existence of dural tears, which were surgically confirmed; 21 patients with dural tears and 10 patients without dural tears. Clinical and radiographic findings were analyzed for their association with dural tears. RESULTS: Among a total of 31 patients, dural tears were detected in 21 (67%) patients. A preoperative neurological deficits and mean separation distances of the edges in laminar fractures were found to be the reliable factors of dural tears (p=0.001 and 0.002, respectively). Decreased ratio of the central canal diameter and interpedicular distance were also the reliable factors suggesting dural tears (p=0.006 and 0.015, respectively). However, dural tears showed no significant association with age, sex, level of injury, absence of a posterior fat pad signal, the angle of retropulsed segment, or site of laminar fracture. CONCLUSION: Our study of lumbar burst fracture combined laminar fracture revealed that dural tears should be ruled out in cases of a preoperative neurological deficits, wide separation of the laminar fracture, severe canal encroachment, and wider interpedicular distance.

Surgical Approach of Thoracolumbar or Lumbar Bursting Fracture with Associated Laminar Fracture

In case of thoracolumbar or lumbar bursting fractures with associated laminar fracture, there are the possibilities of posterior dural lacerations or neural entrapment caused by impaction of the dural sac into the gap of the fractured lamina. We treated thirty six patients of these fractures with anterior or posterior approach during last 10 years. The posterior approach had less delayed kyphosis and postoperative cerebrospinal fluid leakage than the anterior approach. Posterior dural laceration was noted during operation in sixteen cases out of a total of thirty six patients. The statistical analysis revealed significant associations of the dural laceration with preoperative neurological deficits, high grade spinal canal compromise, and comminuted laminar fracture. These patients should undergo posterior exploration of the spinal canal, extraction of neural elements, and repair of the lacerated dura before any spinal reconstruction maneuver.