Is focused magnetic resonance imaging adequate for treatment decision making in acute traumatic thoracic and lumbar spine fractures seen on whole spine computed tomography?

PURPOSE: To assess whether a focused magnetic resonance imaging (MRI) limited to the region of known acute traumatic thoracic or lumbar fracture(s) would miss any clinically significant injuries that would change patient management. STUDY DESIGN/SETTING: A multicenter retrospective clinical study. PATIENT SAMPLE: Adult patients with acute traumatic thoracic and/or lumbar spine fracture(s). OUTCOME MEASURES: Pathology identified on MRI (ligamentous disruption, epidural hematoma, and cord contusion), outside of the focused zone, an alteration in patient management, including surgical and nonsurgical, as a result of the identified pathology outside the focused zone. METHODS: Records were reviewed for all adult trauma patients who presented to the emergency department between 2008 and 2016 with one or more fracture(s) of the thoracic and/or lumbar spine identified on computed tomography (CT) and who underwent MRI of the entire thoracic and lumbar spine within 10 days. Exclusion criteria were patients with >4 fractured levels, pathologic fractures, isolated transverse, and/or spinous process fractures, prior vertebral augmentation, and prior thoracic or lumbar spine instrumentation. Patients with neurologic deficits or cervical spine fractures were also included. MRIs were reviewed independently by one spine surgeon and one musculoskeletal fellowship-trained emergency radiologist for posterior ligamentous complex (PLC) integrity, vertebral injury, epidural hematoma, and cord contusion. The surgeon also commented on the clinical significance of the pathology identified outside the focused zone. All cases in which pathology was identified outside of the focused zone (three levels above and below the fractures) were independently reviewed by a second spine surgeon to determine whether the pathology was clinically significant and would alter the treatment plan. RESULTS: In total, 126 patients with 216 fractures identified on CT were included, with a median age of 49 years. There were 81 males (64%). Sixty-two (49%) patients had isolated thoracolumbar junction injuries and 36 (29%) had injuries limited to a single fractured level. Forty-seven (37%) patients were managed operatively. PLC injury was identified by both readers in 36 (29%) patients with a percent agreement of 96% and κ coefficient of 0.91 (95% CI 0.87-0.95). Both readers independently agreed that there was no pathology identified on the complete thoracic and lumbar spine MRIs outside the focused zone in 107 (85%) patients. Injury outside the focused zone was identified by at least one reader in 19 (15%) patients. None of the readers identified PLC injury, cord edema, or noncontiguous epidural hematoma outside the focused zone. Percent agreement for outside pathology between the two readers was 92% with a κ coefficient of 0.60 (95% CI 0.48-0.72). The two spine surgeons independently agreed that none of the identified pathology outside of the focused zone altered management. CONCLUSIONS: A focused MRI protocol of three levels above and below known thoracolumbar spine fractures would have missed radiological abnormality in 15% of patients. However, the pathology, such as vertebral body edema not appreciated on CT, was not clinically significant and did not alter patient care. Based on these findings, the investigators conclude that a focused protocol would decrease the imaging time while providing the information of the injured segment with minimal risk of missing any clinically significant injuries.

CT for thoracic and lumbar spine fractures: Can CT findings accurately predict posterior ligament complex injury?

PURPOSE: This study aims to determine whether secondary CT findings can predict posterior ligament complex (PLC) injury in patients with acute thoracic (T) or lumbar (L) spine fractures. METHODS: This is a retrospective study of 105 patients with acute thoracic and lumbar spine fractures on CT, with MRI as the reference standard for PLC injury. Three readers graded CT for facet joint alignment (FJA), widening (FJW), pedicle or lamina fracture (PLF), spinous fracture (SPF), interspinous widening (ISW), vertebral translation (VBT), and posterior endplate fracture (PEF). Univariate and multivariate logistic regression analyses were performed separately for each reader to test for associations between CT and PLC injury, and diagnostic performance of CT was calculated. RESULTS: Fifty-three of 105 patients had PLC injury by MRI. Statistically significant predictors of PLC injury were VBT, PLF, ISW, and SPF. Using these four CT findings, odds of PLC injury ranged from 3.8 to 5.6 for one positive finding, but increased to 13.6-25.1 for two or more. At least one positive CT finding was found to yield average sensitivity of 82% and specificity 59%, while two or more yielded sensitivity 46% and specificity 88%. CONCLUSION: While no individual CT finding is sufficiently accurate to diagnose or exclude PLC injury, greater the number of positive CT findings (VBT, PLF, ISW, and SPF), the higher the odds of PLC injury. The presence of a single abnormal CT finding may warrant confirmatory MRI for PLC injury, while two or more CT findings may have adequate specificity to avoid need for MRI prior to surgical intervention. These slides can be retrieved under Electronic Supplementary Material.

Internal Rotation Traction Radiograph Improves Proximal Femoral Fracture Classification Accuracy and Agreement.

OBJECTIVE: The objective of this study is to assess the clinical utility of internal rotation traction radiography in the classification of proximal femoral fractures. MATERIALS AND METHODS: The study cohort included 78 consecutive patients who were surgically treated for a proximal femoral fracture and for whom preoperative physician-assisted internal rotation traction radiographs of the fractured hip were obtained in addition to standard radiographs. Two radiologists who were blinded to clinical information independently classified each fracture without the traction view and then with the traction view. The radiologists also reported their confidence (expressed as a percentage) in their classifications. The reference standard was the consensus interpretation of intraoperative C-arm fluoroscopic images by two orthopedic surgeons and one radiologist. Classification accuracy was compared using the McNemar test. Subjective confidence and confidence-weighted accuracy were compare using paired t tests. Agreement with the reference standard and interreader agreement were calculated using the kappa statistic and were compared using the z-test after bootstrapping was performed to obtain the standard error. RESULTS: With the traction view, the pooled accuracy increased from 44.9% to 72.4%, subjective confidence increased from 87% to 94%, and confidence-weighted accuracy increased from 51.7% to 74.3% (p < 0.001). With the traction view, the kappa statistic for agreement with the reference standard increased from 0.530 to 0.791 and from 0.381 to 0.625 for the two readers, and interreader agreement increased from 0.480 to 0.678 (p < 0.001). CONCLUSION: The addition of an internal rotation traction radiographic view significantly improves radiologist accuracy and confidence as well as interreader agreement in the classification of proximal femoral fractures, all of which would be expected to best guide appropriate surgical management.