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Study Design: Prospective diagnostic imaging study., Objective: To determine the accuracy of magnetic resonance imaging (MRI) in diagnosing injury of the posterior ligamentous complex (PLC) in patients with thoracolumbar trauma., Summary of Background Data: Treatment decisions in thoracolumbar injury patients are currently based on the status of the PLC. It is, therefore, important to understand the accuracy of MRI in diagnosing varying degrees of PLC injury. Prior studies report that MRI is up to 100% sensitive for diagnosing PCL injury., Methods: Patients with an acute injury from T1 to L3 who required posterior surgery were prospectively studied. A musculoskeletal radiologist, based on the preoperative MRI findings, characterized each of the 6 components of the PLC as intact, incompletely disrupted, or disrupted. During the surgical procedure, the surgeon identified each component of the PLC as intact, incompletely disrupted, or disrupted. The radiologist's interpretation and surgical findings were compared., Results: Forty-two patients with 62 levels of injury were studied. There were 33 males (78.6%) and 9 females (21.4%), and the average age was 35.7 years. According to the kappa score, there was a moderate level of agreement between the radiologist's interpretation and the intraoperative findings for all PLC components except the thoracolumbar fascia, for which there was slight agreement. The sensitivity for the various PLC components ranged from 79% (left facet capsule) to 90% (interspinous ligament). The specificity ranged from 53% (thoracolumbar fascia) to 65% (ligamentum flavum). There was less agreement between the radiologist and surgeon for the patients with less severe neurologic compromise, i.e., those patients with an AIS grade of either D or E., Conclusion: The sensitivity and specificity of MRI for diagnosing injury of the PLC are lower than previously reported in the literature. The integrity of the PLC as determined by MRI should not be used in isolation to determine treatment.

Study Design: Retrospective study comparing spinal cord injury (SCI) lesion characteristics in methylprednisolone (MPS) treated versus untreated patients as demonstrated by magnetic resonance (MR) imaging., Objective: Determine if the administration of MPS immediately following SCI affects lesion severity., Summary of Background Data: The administration of MPS in the setting of acute SCI has become controversial. Since magnetic resonance imaging (MRI) is sensitive for the detection of spinal cord edema and hemorrhage, changes in lesion characteristics would support a biologic effect due to MPS., Methods: Patients with cervical spinal injury treated with the recommended dose of methylprednisolone (bolus 30 mg/kg + 5.4 mg/kg per hour over 24 hours) initiated within 8 hours of injury were compared to historical controls that did not receive steroids. All patients (n = 82) sustained clinically complete SCI (ASIA Grade A) and underwent MRI on the same 1.5 Tesla unit. The length of spinal cord edema, presence/absence of intramedullary hemorrhage, and length of intramedullary hemorrhage were measured on T2-weighted and gradient echo MR images. Comparisons of lesion severity were then made between untreated and treated subjects., Results: Forty-eight of 82 patients with complete injuries received MPS therapy. After accounting for differences in the mean age of the treatment and control groups, multiple regression analysis demonstrated a persistent reduction in the mean length of intramedullary hemorrhage, 2.6 U in the treatment group versus 4.4 U in the control group (P = 0.04). Although there was a reduction in the number of patients exhibiting spinal cord hemorrhage in the treated group compared with the untreated group (65% vs. 91%), this result was not statistically significant (P = 0.16). There was no statistically significant effect of MPS treatment on the mean length of the spinal cord edema between treated versus untreated subjects (10.3 vs. 12.0, respectively, P = 0.85)., Conclusions: MRI suggests MPS therapy in the acute phase of spinal cord injury may decrease the extent of intramedullary spinal cord hemorrhage.

Study Design: A retrospective study was performed with the use of magnetic resonance imaging to evaluate the type and degree of soft tissue disruption associated with flexion-distraction injuries of the subaxial spine., Objective: To determine what soft tissue structures are injured in flexion-distraction injuries of the subaxial spine., Summary of Background Data: Prior published reports of unilateral and bilateral cervical facet dislocations have described the analyzed mechanisms and biomechanics of this injury subtype. No retrospective magnetic resonance imaging analysis of associated soft tissue disruption has been documented., Methods: Magnetic resonance imaging evaluations of the cervical spine were obtained for all patients with a flexion-distraction injury, Stages 2 (unilateral facet dislocation) and 3 (bilateral facet dislocation), between September 1994 and May 1998. Two neuroradiologists, blinded to both clinical and radiographic findings, graded all the soft tissue structures for evidence of attenuation or disruption. The soft tissue structures were graded on a scale of 1 (intact), 2 (indeterminate), or 3 (disrupted)., Results: For this study, 48 patients satisfied the inclusion criteria: 25 with unilateral facet dislocation and 23 with bilateral facet dislocation. Disruption to the posterior musculature, interspinous ligament, supraspinous ligament, facet capsule, ligamentum flavum, and posterior and anterior longitudinal ligaments was found in a statistically significant number of patients with bilateral facet dislocation. For most of these structures, disruption was found to be statistically significant in patients with a unilateral facet dislocation, except for the posterior longitudinal ligament, in which significance was not consistently demonstrated using 95% confidence intervals in the binomial testing. In a comparison between unilateral and bilateral facet dislocations using a two-sided Fisher's exact test, it was found that disruption to the anterior and posterior longitudinal ligaments and the left facet capsule were statistically significant, with all three more prominent in bilateral facet dislocation. A multivariate analysis between unilateral and bilateral facet dislocations showed that disruption to the anterior longitudinal ligament was associated significantly with a bilateral facet dislocation. Disc disruption was found to be associated significantly with both injury types, but was more common in bilateral facet dislocation, although this difference in intergroup comparisons was not statistically significant., Conclusions: Unilateral and bilateral facet dislocations of the subaxial spine are associated with damage to numerous soft tissue structures that provide stability to the lower cervical spine. Damage to the posterior longitudinal ligament did not occur consistently in unilateral facet dislocations. Bilateral facet dislocations were associated significantly with disruption to the posterior and anterior longitudinal ligaments and left facet capsule, as compared with unilateral facet dislocations. Magnetic resonance imaging allows visualization of these disruptions.

Study Design: A prospective clinical study using magnetic resonance imaging of the cervical spine in a consecutive series of patients with cervical spine dislocations., Objectives: To determine the incidence of intervertebral disc herniations and injury to the spinal ligaments before and after awake closed traction reduction of cervical spine dislocations., Summary of Background Data: Prior series in which the prereduction imaging of disc herniations in the dislocated cervical spine are described have been anecdotal and have involved small numbers of patients. In addition, no uniform clinical criteria to define the presence of an intervertebral disc herniation in the dislocated cervical spine has been described. The incidence of disc herniations in the unreduced dislocated cervical spine is unknown., Methods: Eleven consecutive patients with cervical spine dislocations who met the clinical criteria for an awake closed traction reduction had prereduction and postreduction magnetic resonance imaging. Using strict clinical criteria for the definition of an intervertebral disc herniation, the presence or absence of disc herniation, spinal ligament injury, and cord injury was determined. Neurologic status before, during, and after the closed reduction maneuver was documented., Results: Disc herniations were identified in 2 of 11 patients before reduction. Awake closed traction reduction was successful in 9 of the 11 patients. Of the nine patients with a successful closed reduction, two had disc herniations before reduction, and five had disc herniations after reduction. No patient had neurologic worsening after attempted awake closed traction reduction., Conclusions: The process of closed traction reduction appears to increase the incidence of intervertebral disc herniations. The relation of these findings, however, to the neurologic safety of awake closed traction reduction remain unclear.

Study Design: A prospective study to determine the long-term outcome of traumatically induced vertebral artery injuries. Magnetic resonance angiography was performed at the time of cervical injury and at a follow-up office visit., Objective: To determine the long-term outcome in terms of arterial flow competency of traumatically induced vertebral artery injuries., Summary of Background Data: Vertebral artery injury associated with cervical spine trauma has been well documented; however its healing or nonhealing potential has not been elucidated., Methods: During the 7-month period from July 1993 to January 1994, all patients admitted to the authors' institution with cervical spine injuries underwent magnetic resonance imaging and magnetic resonance angiography of the cervical spine to determine the patency of their vertebral arteries. Magnetic resonance angiography was performed at the time of injury and at a follow-up office visit. Twelve of 61 patients were found to have a lack of signal flow within one of their vertebral vessels during this study period., Results: Eighty-three percent of the patients (five of six) who were available for follow-up observation in this study did not manifest flow reconstitution of their vertebral arteries after an average 25.8-month follow-up period., Conclusions: According to these data, most patients with vertebral artery injuries after nonpenetrating cervical spine trauma do not reconstitute flow in the injured vertebral arteries. This lack of flow must be considered if future surgery in this region of the cervical spine is contemplated.