ABSTRACT
Study DesignProspective diagnostic imaging study.PurposeThe stability of the thoracic and lumbar spine depends significantly on the posterior ligamentum complex (PLC). Therefore, it is essential to diagnose PLC injuries accurately before deciding on a treatment plan for thoracolumbar injury patients. However, the efficacy of magnetic resonance imaging (MRI) in diagnosing PLC remains undetermined.Overview of LiteratureMRI has become the ultimate tool in diagnosing spine injury cases, as previous literature suggests that it has very high sensitivity and specificity. But this is still controversial and as many surgeons rely on just MRI for selecting the patient for surgery, it becomes important to know the diagnostic accuracy of it.MethodsPatients who sustained injuries from T1 to L3 and required posterior surgery were prospectively studied. The treating surgeon and musculoskeletal radiologist participating in the study reviewed preoperative MRI images to characterize the level(s) of injury and the integrity of the six components of the PLC. These were classified as intact, incompletely disrupted, or disrupted. During the surgical procedure, the surgeon also classified each component of the PLC, and the radiologist’s and surgeon’s findings were compared.ResultsOut of 66 patients, 46 were males (69.7%) and 20 were females (30.3%), and the average age was 34.12 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 for the thoracolumbar fascia and ligamentum flavum for which there was a slight agreement. The sensitivity for the intact PLC components ranged from 100% (supraspinous ligament) to 66.67% (ligamentum flavum). The specificity ranged from 100% (interspinous ligament) to 52% (thoracolumbar fascia). The Spearman’s rank correlation ranged from 0.061 for the thoracolumbar fascia to 0.918 for the interspinous ligament, and the percentage agreement ranged from 81.82% (interspinous ligament to 36.36% (thoracolumbar fascia).ConclusionsThe sensitivity and specificity of MRI for diagnosing injury of the PLC in this study were lower than those previously reported in the literature. The integrity of the PLC as determined by MRI should not be used in isolation to determine treatment.
ABSTRACT
Study DesignProspective diagnostic imaging study.PurposeThe stability of the thoracic and lumbar spine depends significantly on the posterior ligamentum complex (PLC). Therefore, it is essential to diagnose PLC injuries accurately before deciding on a treatment plan for thoracolumbar injury patients. However, the efficacy of magnetic resonance imaging (MRI) in diagnosing PLC remains undetermined.Overview of LiteratureMRI has become the ultimate tool in diagnosing spine injury cases, as previous literature suggests that it has very high sensitivity and specificity. But this is still controversial and as many surgeons rely on just MRI for selecting the patient for surgery, it becomes important to know the diagnostic accuracy of it.MethodsPatients who sustained injuries from T1 to L3 and required posterior surgery were prospectively studied. The treating surgeon and musculoskeletal radiologist participating in the study reviewed preoperative MRI images to characterize the level(s) of injury and the integrity of the six components of the PLC. These were classified as intact, incompletely disrupted, or disrupted. During the surgical procedure, the surgeon also classified each component of the PLC, and the radiologist’s and surgeon’s findings were compared.ResultsOut of 66 patients, 46 were males (69.7%) and 20 were females (30.3%), and the average age was 34.12 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 for the thoracolumbar fascia and ligamentum flavum for which there was a slight agreement. The sensitivity for the intact PLC components ranged from 100% (supraspinous ligament) to 66.67% (ligamentum flavum). The specificity ranged from 100% (interspinous ligament) to 52% (thoracolumbar fascia). The Spearman’s rank correlation ranged from 0.061 for the thoracolumbar fascia to 0.918 for the interspinous ligament, and the percentage agreement ranged from 81.82% (interspinous ligament to 36.36% (thoracolumbar fascia).ConclusionsThe sensitivity and specificity of MRI for diagnosing injury of the PLC in this study were lower than those previously reported in the literature. The integrity of the PLC as determined by MRI should not be used in isolation to determine treatment.
ABSTRACT
STUDY DESIGN: Retrospective study. PURPOSE: To evaluate the clinico-radiological efficacy of stand-alone minimally invasive transarticular screw (MIS-TAS) fixation without supplemental Gallie fixation in the management of mobile C1–C2 instability. OVERVIEW OF LITERATURE: Data evaluating the efficacy and feasibility of MIS-TAS in the literature is scanty. METHODS: Patients with mobile atlantoaxial instability and >2 years follow-up were included and managed by stand-alone TAS fixation using the Magerl technique and morselized allograft without additional fixation. Patient demographics and intra-operative parameters were noted. Clinical parameters (Visual Analog Scale [VAS] and Oswestry Disability Index [ODI]), neurology (modified Japanese Orthopaedic Association [mJOA]), and radiological factors (anterior atlanto-dens interval and space available for cord) were evaluated pre and postoperatively. Computed tomography (CT) was performed in patients who did not show interspinous fusion on X-ray at 1 year, to verify intra-articular fusion. Statistical analysis was performed using IBM SPSS ver. 20.0 (IBM Corp., Armonk, NY, USA); the Student t-test and analysis of variance were used to assess statistical significance (p <0.05). RESULTS: A total of 82 consecutive cases (three males, one female; mean age, 36.26±5.78 years) were evaluated. In total, 163 TASs were placed. Significant improvement was noticed in clinical (mean preoperative VAS=7.2±2.19, postoperative VAS=3.3±1.12; mean preoperative ODI=78.3±4.83, postoperative ODI=34.05±3.26) and neurological features (mean preoperative mJOA=14.73±2.68, postoperative mJOA=17.5±2.21). Radiological evidence of fusion was noted in 97.5% cases at final follow-up. Seventeen patients were found to have no interspinous fusions upon X-rays, but CT revealed facet fusion in all patients except in two. Inadvertent vertebral artery injury was noted in three cases. CONCLUSIONS: Stand-alone TAS fixation with morselized allograft provides excellent radiological and clinical outcomes. The addition of a supplementary tension band and structural graft are not essential. This provides the opportunity to avoid the complications associated with graft harvesting and wiring.