Role of weight-bearing flexion and extension myelography in evaluating the intervertebral disc.

Magnetic resonance imaging has many advantages compared with myelography and/or computed tomography in evaluating the lumbar spine for herniated nucleus pulposus. The authors have included a series of three patients whose histories and physical examinations were clinically suggestive of herniated nucleus pulposus but whose magnetic resonance imaging scans were interpreted by a radiologist as a disc bulge without nerve root compression. Because all patients had not responded to a conservative care treatment program and surgical intervention was to be considered, subsequent testing with lumbar myelography with weight-bearing flexion and extension views demonstrated more clearly the presence of herniated nucleus pulposus along with compression of the nerve root; it also revealed that a positional change in the disc occurred with flexion and extension.