RESUMEN
Functional myelography, applying spinal movements(flexion-extension) in myelography, has been frequently used for accurate diagnosis of posture-related disorders such as herniated lumbar disc or spinal stenosis. Measurements were performed on functional myelographic findings of 62 patients, and in 24 cases surgically verified herniated lumber discs were present. The object of this study was to analyze changes in position and shape of the dural sac in spinal movements and confirm the clinical importance of functional myelography. The present study demonstrated that: 1) The anterior border of the dural sac was straight with flexion, but indented at the level of intervertebral space and this indentation was less prominent at L5-S1. 2) With extension, posterior indentation of the dural sac was more prominent at the level of the intervertebral space than the body, the A-P diameter of the dural sac was narrowed at all levels of the intervertebral spaces except L5-S1, and the dural sac moved anteriorly at the level of L5-S1 and all spinal bodies. 3) In surgically verified disc patients, anterior indentation of the dural sac was persistent in both flexion and extension views, and was more exaggerated with extension, but less prominent at L5-S1. In patient at L5-S1, anterior movement of the anterior dural border at the level of surgery was much decreased.