Predictive value of radiculography in patients with lumbago-sciatica. A prospective study (Part II).

One hundred patients with symptoms of lumbo-sacral root compression were prospectively and consecutively assigned to operation based alone on clinical findings. A preoperative myelogram was performed in all patients and described without a knowledge of the clinical features. All patients were explored for the clinically and myelographically relevant disc. When the myelogram was normal (16 patients) both lower lumbar interspaces were exposed. In 58 patients a herniated disc was revealed at surgery. Only "myelographic herniation" with indentation of the contrast column was accompanied by a high frequency of disc herniation at surgery (73-87%). In cases with normal myelograms only 5% had a disc herniation. The severity of the myelographic finding was clearly correlated to the frequency of positive surgical findings and good outcomes. The preoperative radiculogram gives a high degree of certainty in the preoperative evaluation whether a surgical lesion is present or not and reveals a precise prediction of the outcome of surgery.