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

Although magnetic resonance imaging is the primary modality of investigation for determining the extent of posterior ligamentous complex (PLC) injuries in lower lumbar fractures (LLF) (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 PLC injury in patients with LLF.

We retrospectively analyzed data from 108 patients who presented with traumatic LLF. CT parameters like loss of vertebral body height, local kyphosis, retropulsion of fracture fragment, interlaminar distance, interspinous distance, supraspinous distance, interpedicular distance, canal compromise, facet joint diastasis in axial images (FJD_A) and facet joint diastasis in sagittal images (FJD_S), and 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 magnetic resonance imaging as a reference standard.

Among 108 patients, PLC injury was identified in 57 (52.8%). On univariate analysis, local kyphosis, retropulsion of fracture fragment, interlaminar distance, interpedicular distance, FJD_S, FJD_A, 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, FJD_S (P = 0.039) and FJD_A (P = 0.003) were found to be variables independently associated with PLC injury.

Among the various CT parameters, facet joint diastasis (FJD_S > 4.2 mm and FJD_A > 3.5 mm) is the most reliable factor in determining PLC injury.