Spinal imaging and intervention: 1998.

Imaging of the lumbar spine is the most common application of magnetic resonance (MR) imaging in many radiologic practices. MR imaging has replaced computed tomography (CT) and CT myelography as the primary mode of spinal imaging and has relegated myelography to a secondary role in the evaluation of lumbar spinal disorders. At the same time, however, it has become evident that the correlation between gross anatomic findings as depicted on MR images and the clinical signs and symptoms detected by the clinician may be lacking. Defining the precise anatomic source of patients' complaints on the basis of imaging studies must be approached judiciously because a significant proportion of the population has disc disease as depicted on imaging studies, yet many have no clinical findings.

Lumbar spine following successful surgical discectomy. Magnetic resonance imaging features and implications.

In an attempt to determine the expected long-term appearance of the lumbar spine in patients who have undergone successful lumbar discectomy, follow-up magnetic resonance (MR) examinations were performed on 23 patients (26 levels). All patients in the study had undergone at surgery at least one year prior to the study. All patients met rigorous criteria for a successful outcome. In nine cases, the postoperative study indicated a virtually total resolution of the previously identified disc herniations. In 13 cases, the study noted moderate, persistent posterior contour defects in the disc that contributed to persistent mass effect on the thecal sac or corresponding nerve root. In the remaining four cases, the postoperative study indicated virtually no change in the apparent contour of the posterior disc margin. Gadolinium contrast examinations demonstrated enhancement of the persistent contour abnormalities in 18 of 19 disc levels, suggesting the common presence of fibrosis, which was at times "mass-like," in these successful patients. These findings suggest that localized discal contour abnormalities morphologically simulating recurrent disc herniations and variably contributing to mass effect, may be commonly encountered in long-term follow-up imaging studies of successful discectomy patients.

Early experience with automated percutaneous lumbar discectomy in the treatment of lumbar disc herniation.

Seventeen patients with symptomatic lumbar disc herniation were treated with automated percutaneous lumbar discectomy employing local anesthetic in an outpatient setting. Operative technique included (1) intravenous sedation and single-dose antibiotics, (2) prone oblique patient positioning for initial needle placement, and (3) postdiscectomy interspace lavage with bupivacaine hydrochloride. There were no postoperative complications and the procedure was well-tolerated by all patients. Although results have thus far been less successful than previously reported, with improved patient selection by means of routine magnetic resonance imaging (or computed tomographic discography in select cases), success rates (nine of 17 patients) might approach those achieved by chemonucleolysis. The successful response of four patients with so-called midline L4-L5 discs has been particularly encouraging, and it may be that percutaneous lumbar discectomy will be an effective and a reasonable treatment alternative for this particular subgroup of patients.