Relevancy of Posterior Column Injury and Dural Tear in Unstable Burst Fracture

ABSTRACT

PURPOSE: To analyze the pattern of posterior column injury in unstable burst fractures and to predict the possibility of dural injury. MATERIALS AND METHODS: Retrospective review was carried out on 22 patients of unstable burst fracture from Nov. 1996 to Sep. 2003. The pattern posterior column injury was analyzed by simple x-ray, CT and MRI findings. In simple x-ray, authors analyzed laminar fracture, posterior facet injury, inter-spinous widening and inter-spinous malalignment, posterior bony injury by CT, posterior inter-spinous ligament injury and dural tear by MRI. The statistical analysis was performed using Mann-Whitney test and Chi-square test. RESULTS: There were 13 men and 9 women, and mean age was 41 years-old (18~65). The level of injury showed 15 cases in T12-L2, 6 in L3, 3 L4. In simple x-ray, findings were showed 13 cases (59.1%) in laminar fracture, 7 (31.8%) in posterior facet injury, 16 (72.7%) in inter-spinous widening and 8 (36.4%) in inter-spinous malalignment. In CT, findings were showed 13 (59.1%) in laminar fracture, 10 (45.5%) in posterior facet injury, 9 (40.9%) in transverse process fracture. In MRI, findings were showed 18 (81.8%) in posterior inter-spinous ligament injury and were not showed dural tear. The combined cases of posterior bony and ligamentous injury was 6 (27%) and 5 of 6 showed dural tear and the analysis of dural tear and radiologic findings was showed positive correlation (p=0.004). CONCLUSION: Posterior ligament injury was more frequent than bony injury in unstable burst fracture. Among the posterior bony injuries, dural tear was more frequent in facet injury. Authors confirmed all dural tear with operation. In cases of posterior bony injury combined with ligamentous injuries, the possibility of dural tear was significantly higher than that of single structural injury (p=0.004).