Risk Factors for Dural Tears in Thoracic and Lumbar Burst Fractures Associated With Vertical Laminar Fractures.

STUDY DESIGN: Retrospective cohort study.

OBJECTIVE: To reveal the risk factors for dural tears in thoracic and lumbar (TL) burst fractures associated with vertical laminar fractures through multivariate analysis.

SUMMARY OF BACKGROUND DATA: Dural tears associated with laminar fractures in patients with TL burst fractures represents a special group requires distinct treatment with different surgical prognosis. It is still very difficult to predict dural tears in patients with vertical laminar fractures. The risk factors for dural tears have seldom been evaluated.

METHODS: Medical records of 113 patients of TL burst fractures with vertical laminar fractures were reviewed. The data were subdivided into two groups consisting of patients with and without dural tears. Demographic information, preoperative clinical, and radiological characteristics were compared between the groups. Multivariate logistic regression models were employed to determine the independent risk factors for dural tears.

RESULTS: The incidence of dural tear was 27.4% in this retrospective cohort. When compared with the dural intact group, the dural tear group had significantly worse preoperative neurological status, wider interpedicular distance, greater separation of laminar fractures, and larger encroachment of retropulsed fragment in the bony spinal canal. Multivariate stepwise logistic regression analysis showed that the ratio of interpedicular distance greater than 125% (odds ratio = 9.5; P < 0.001) and the ratio of encroachment of retropulsed fragment in the bony spinal canal of more than 50% (odds ratio = 61.2; P < 0.001) were independent risk factors for dural tears.

CONCLUSION: Patients with wider interpedicular distance and larger encroachment of retropulsed fragment in the bony spinal canal were more likely to have dural tears in TL burst fractures with vertical laminar fractures.

LEVEL OF EVIDENCE: 3.