CT changes after conservative treatment for lumbar disk herniation.

In order to assess changes occurring to lumbar disk herniations and bulges and to the disk spaces after conservative treatment, a follow-up CT was carried out of 106 pathologic disks in 92 patients at a mean interval of 14 months after the initial examination. There was a strong association between the evolution of the hernias and clinical results, with a decrease in size of the majority of hernias in successfully treated patients, whereas the others essentially remained unchanged (p < 0.0001). A significantly higher proportion of large hernias diminished as compared to the smaller ones (p < 0.0001). Diffuse disk bulges were associated with a poor outcome and never regressed. There was a lower incidence of diminution of the central hernias compared to other locations. Patients with normal disk space at the initial examination had a better outcome than those with disk space narrowing. Only occasionally was a reduction of the disk space observed at follow-up.