Diagnostic Reliability of Computed Tomography in Predicting Posterior Ligamentous Complex Injury in Traumatic Lower Lumbar Fracture

Abstract

ObjectiveThough magnetic resonance imaging (MRI) is the primary modality of investigation for determining the extent of PLC injuries in lower lumbar fractures (L3-L5), the reliability of computed tomography (CT) has not been well defined. The main objective of this study is to analyze the diagnostic accuracy of combined CT findings for detecting posterior ligamentous complex injury in patients with lower lumbar fractures. MethodsWe retrospectively analyzed data from 108 patients who presented with traumatic lower lumbar fractures. CT parameters like loss of vertebral body height, local kyphosis, retropulsion of fracture fragment, interlaminar distance (ILD), interspinous distance (ISD), supraspinous distance (SSD), interpedicular distance (IPD), canal compromise, facet joint diastasis in axial images (FJDA) and sagittal images (FJDS), presence of lamina and spinous process fracture were calculated using axial and sagittal CT images. The presence or absence of PLC injury was determined using MRI as a reference standard. ResultsAmong 108 patients PLC injury was identified in 57 (52.8%). On univariate analysis local kyphosis, retropulsion of fracture fragment, ILD, IPD, FJDS, FJDA, and the presence of spinous process fracture were found to be significant (P < 0.05) in predicting PLC injury. Whereas on multivariate logistic regression analysis, FJDS (P= 0.039), and FJDA (P= 0.003) were found to be variables independently associated with PLC injury. ConclusionAmong the various CT parameters, facet joint diastasis (FJDS > 4.2 mm and FJDA > 3.5 mm) is the most reliable factor in determining PLC injury.