CT five years after myelographic diagnosis of lumbar disk herniation.

Fifty-seven patients were examined with CT 5 years after primary myelography for disabling sciatica and suspected herniated lumbar disk. Forty were in an operated group, 22 with good and 18 with poor results evaluated by occupational handicap (21) 5 years after surgery. Seventeen patients had myelography indicating disk herniation, but were treated conservatively, 9 with good and 8 with poor result. Various spinal dimensions measured at CT did not correlate with outcome. Operated patients had narrower canals than others, and male canals were broader than those in females. Increased amount of scar tissue at L4 level correlated with poor result (p = 0.008). Operated patients with poor result had more advanced lateral stenosis than those treated conservatively (p less than 0.001). Patients with good result after operation had more degeneration observed on CT of erector spinae muscle than those treated conservatively with good outcome. Only 9% of operated patients did not have muscle degeneration. A tendency for more frequent recurrent disk herniations could be seen for conservatively treated patients. The narrowing of the spinal canal 5 years after operation did not correlate with the 5-year outcome.