Abstract
Radicular pain can occur in either subarticular entrapment in the lateral recess or central stenosis. Because many central stenosis patients were associated with subarticular entrapment, the incidence of subarticular entrapment as a cause of radicular pain has not yet been elucidated. Magnetic resonance myelography (MRM) can differentiate subarticular entrapment from central stenosis by visualization of the nerve root in the distal portion of compression. In the present study, morphologies of the root sleeve in patients with painful radiculopathy due to spinal canal stenosis were determined on MR myelograms. Of 65 affected nerve roots in 48 consecutive patients (M/F = 25/23, mean age = 68.2 years), 35 nerve roots showed purely antero-posterior compression (subarticular entrapment) and 30 nerve roots showed medial deviation. The site of compression was classified as above (8) or at the exit of the root sleeve from the dural tube (57).
