The value of the posterior ligamentous complex in traumatic injury of thoracolumbar junction. Part 2. Diagnostic methods

The posterior ligamentous complex (PLC) of the spinal motion segment consists of the supraspinous, interspinous ligaments, ligamentum flavum, and facet joint capsules. The state of this functional combination of ligamentous structures is considered a critical predictor of stability in traumatically injured spine. Despite the practical importance of the PLC concept, it has mainly been used for theoretical evaluation of spinal stability models for a long time. Literature analysis reveals a lack of consensus regarding diagnostic criteria for PLC injuries and their clinical significance. The results of some studies are conflicting. This review attempts to organize information on diagnostic methods for assessing the status of different elements of the PLC in traumatic injuries of the thoracolumbar junction. Currently, there is no universally accepted criteria to help verify PLC injuries. Many signs have diagnostic value, which can be categorized as direct or indirect based on the visualization method. Direct signs are based on the analysis of images that characterize specific anatomical structures. Indirect signs allow for the assessment of the PLC considering the state and location of adjacent, primarily bony, structures. The review examines the diagnostic capabilities of visualization methods such as spondylography, spiral computed tomography, magnetic resonance imaging, and ultrasound with identification of their main advantages and disadvantages. It is found that the broader capabilities of magnetic resonance imaging in visualizing soft tissue structures do not significantly improve diagnostic quality. Spiral computed tomography remains the leading method, both for evaluating bone traumatic changes and determining indirect signs of PLC injury. The development and clinical verification of spiral computed tomography characteristics for assessing the status of the ligamentous apparatus are important tasks in improving the quality of care for patients with thoracolumbar junction injuries.