OBJECTIVE: Myelography has been shown to highlight foraminal and lateral recess stenosis more readily than computed tomography (CT) or magnetic resonance imaging (MRI). It also has the advantage of providing dynamic assessment of stenosis in the loaded spine. The advent of weight-bearing MRI may go some way towards improving assessment of the loaded spine and is less invasive, however availability remains limited. This study evaluates the potential role of myelography and its impact upon surgical decision making. METHODS: Of 270 patients undergoing myelography during 2006–2009, a period representing peak utilisation of this imaging modality in our unit, we identified 21 patients with degenerative scoliosis who fulfilled our inclusion criteria. An operative plan was formulated by our senior author based initially on interpretation of an MRI scan. Subsequent myelogram and CT myelogram investigations were scrutinised, with any additional abnormalities noted and whether these impacted upon the operative plan. RESULTS: From our 21 patients, 18 (85.7%) had myelographic findings not identified on MRI. Of note, in 4 patients, supine CT myelography yielded additional information when compared to supine MRI in the same patients. The management of 7 patients (33%) changed as a result of myelographic investigation. There were no complications of myelography of the total 270 analysed. CONCLUSION: MRI scan alone understates the degree of central and lateral recess stenosis. In addition to the additional stenosis displayed by dynamic myelography in the loaded spine, we have also shown that static myelography and CT myelography are also invaluable tools with regards to surgical planning in these patients.
Congenital Abnormalities ; Constriction, Pathologic ; Decision Making ; Humans ; Magnetic Resonance Imaging ; Myelography* ; Scoliosis* ; Spine ; Weight-Bearing

STUDY DESIGN: Radiologic imaging measurement study. PURPOSE: To assess the accuracy of detecting lateral mass and facet joint injuries of the subaxial cervical spine on plain radiographs using computed tomography (CT) scan images as a reference standard; and the integrity of morphological landmarks of the lateral mass and facet joints of the subaxial cervical spine. OVERVIEW OF LITERATURE: Injuries of lateral mass and facet joints potentially lead to an unstable subaxial cervical spine and concomitant neurological sequelae. However, no study has evaluated the accuracy of detecting specific facet joint injuries. METHODS: Eight spinal surgeons scored four sets of the same, randomly re-ordered, 30 cases with and without facet joint injuries of the subaxial cervical spine. Two surveys included conventional plain radiographs series (test) and another two surveys included CT scan images (reference). Facet joint injury characteristics were assessed for accuracy and reliability. Raw agreement, Fleiss kappa, Cohen's kappa and intraclass correlation coefficient statistics were used for reliability analysis. Majority rules were used for accuracy analysis. RESULTS: Of the 21 facet joint injuries discerned on CT scan images, 10 were detected in both plain radiograph surveys (sensitivity, 0.48; 95% confidence interval [CI], 0.26-0.70). There were no false positive facet joint injuries in either of the first two X-ray surveys (specificity, 1.0; 95% CI, 0.63-1.0). Five of the 11 cases with missed injuries had an injury below the lowest visible articulating level on radiographs. CT scan images resulted in superior inter- and intra-rater agreement values for assessing morphologic injury characteristics of facet joint injuries. CONCLUSIONS: Plain radiographs are not accurate, nor reliable for the assessment of facet joint injuries of the subaxial cervical spine. CT scans offer reliable diagnostic information required for the detection and treatment planning of facet joint injuries.
Diagnostic Imaging ; Humans ; Reproducibility of Results ; Spinal Injuries ; Spine* ; Tomography, X-Ray Computed ; Zygapophyseal Joint*