MULTICENTER EXTERNAL VALIDATION OF THE ACCURACY OF COMPUTED TOMOGRAPHY CRITERIA FOR DETECTING THORACOLUMBAR POSTERIOR LIGAMENTOUS COMPLEX INJURY

Abstract

Background and Objective

Recent studies have proposed computed tomography (CT) criteria for posterior ligamentous complex (PLC) injury: disrupted if ? 2 CT findings, indeterminate if single finding, and intact if 0 CT findings. The study aims to validate the CT criteria for PLC injury externally.

Methods

Three level 1 trauma centers enrolled 614 consecutive patients with acute thoracolumbar fractures (T1- L5) who received Computed tomography (CT) and magnetic resonance imaging (MRI). Three reviewers from each center were the patients from the respective center for sessed CT for facet joint malalignment, horizontal laminar fracture, spinous process fracture, and interspinous widening and MRI for disrupted PLC. The primary outcome is the diagnostic accuracy of CT criteria (0,1, ? 2 findings) in detecting disrupted PLC on MRI using all CT readings. Subgroup analysis for each participating center and reviewer was done. The inter-reader agreement on PLC status on MRI and CT criteria was assessed using Fleiss Kappa (k).

Results

The positive predictive value (PPV) for PLC injury was 0 findings, 3%; single positive CT, 43%; ? 2 CT findings, 94%, and was consistent among different centers and reviewers. The AUC for ? 1 CT findings in detecting PLC injury ranged from 90% to 97%, indicating excellent discrimination for all centers. The inter-reader k on PLC status by MRI and CT criteria was substantial (k >0.60).

Conclusions

This study externally validates the previously proposed CT criteria for PLC injury. ? 2 positive CT findings or 0 CT findings can be used as criteria for a disrupted PLC (B-type injury) or intact PLC (A-type injuries), respectively, without added MRI. A single CT finding implies indeterminate PLC status and the need for further MRI assessment. The CT criteria will potentially guide MRI indications and treatment decisions for burst fractures in patients without neurological impairment.