Diagnostic accuracy of magnetic resonance imaging for detecting posterior ligamentous complex injury associated with thoracic and lumbar fractures

Abstract

Object The posterior ligamentous complex (PLC) in the thoracic and lumbar spine is one of the region's important stabilizers. The precise diagnosis of PLC injury is required to evaluate the instability of the injured spine; however, the accuracy of magnetic resonance (MR) imaging for diagnosing PLC injury has remained unclear. In this study, the authors compared preoperative MR imaging findings with direct intraoperative observation of PLC injury, clarifying the former's diagnostic accuracy regarding detection of PLC injury associated with the thoracic and lumbar fractures. Methods Data obtained in 35 patients who sustained thoracic or lumbar injuries were reviewed. There were 17 burst fractures, six flexion—distraction injuries, and 12 fracture dislocations. Each patient underwent MR imaging examination within 3 weeks of injury. Three radiologists independently evaluated sagittal MR images in a blinded fashion. The PLC-related information was retrospectively collected from each operative record. The diagnostic accuracy of MR imaging was analyzed by comparing imaging-documented intraoperative findings. The PLC injuries were detected in 23 patients (65.7%) by direct observation during posterior spinal procedures. The diagnostic accuracy of MR imaging in detecting injury of the supraspinous ligament (SSL) and interspinous ligament (ISL) was 90.5 and 94.3%, respectively. The specificity of T1-weighted MR imaging alone for depicting the SSL was significantly greater than T2-weighted imaging alone (p < 0.05). The overall mean κ coefficient for MR imaging findings of PLC injury was 0.803, which indicated excellent interobserver reliability; that for ISL (0.915) was significantly greater than that for SSL (0.69) (p < 0.05). Conclusions This study clarified a high diagnostic accuracy and interobserver reliability of MR imaging for PLC injury. The precise diagnosis of PLC injury is essential to determine the mechanical instability of the injured thoracic and lumbar spine, especially in differentiating unstable (three-column) burst fractures from the relatively stable (two-column) type. The authors conclude that MR imaging is a powerful diagnostic tool to evaluate PLC injury associated with thoracic and lumbar fractures.

Spinal Cord Injury after Blunt Cervical Spine Trauma: Correlation of Soft-Tissue Damage and Extension of Lesion

“…[25][26][27][28] In several studies, MR imaging was also sensitive for the evaluation of injury of the posterior ligamentous complex 19,24 ; this suggests that injury to ALL may be underestimated with the use of MR imaging, if the findings are considered in isolation. The explanation is that ALL and PLL adhere to the disk, whereas only the ALL adheres to the vertebrae, such that the PLL is easier to identify.…”

The precision, accuracy and validity of detecting posterior ligamentous complex injuries of the thoracic and lumbar spine: a critical appraisal of the literature

“…This, in combination with a low methodological quality of most of the TLISS validation studies (see Table 2) [18,[20][21][22] leaves the presented agreement values incomparable to results from other precision studies. Those studies that assessed the precision of detecting ISL and SSL injuries specifically demonstrated promising agreement values [17,31]. However, as only three radiologists were involved in these studies [17,31] the agreement among spine specialists still warrants further investigation.…”

“…This resulted in a total number of 21 included articles of this review. Eight studies evaluated the agreement on PLC injury evaluation [15][16][17][18][19][20][21][22], another eight studies evaluated the accuracy of detecting PLC injuries [23][24][25][26][27][28][29][30] and one study evaluated both agreement and accuracy [31]. Four studies reported on different validity components of PLC injuries [32][33][34][35].…”

“…Two studies evaluated the accuracy of detecting an injury of the PLC as a broad entity on MR imaging [30,31]. Although detailed accuracy data were not presented, the PPVs and NPVs were high ([93 %).…”

“…All of the classification validation studies evaluated PLC injury as a broad entity only, except from Schweitzer et al [16], who also evaluated diastasis of the facet joints on CT and 'posterior' oedema-like signal on MR imaging. In the two remaining studies [17,31], ruptures of the SSL and ISL on MR imaging were assessed and considered representative of a PLC injury. Table 3 presents the agreement values on the detection of PLC injuries as reported in and extracted from included studies.…”