Indications for lumbar microdiskectomy.

A very high percentage of patients coming to surgery for large disk extrusions and sciatica do very well with minimally invasive diskectomy. In most patients given relatively early surgical treatment, the primary predictor of outcome is the size of the disk herniation and the remaining competency of the anulus fibrosus. With the passage of time and with prolonged disability before surgery, psychosocial factors become increasingly important in determining outcomes. Factors such as psychological distress, depression, involvement with workers' compensation claims and disability claims, drug and alcohol abuse, and level of education appear to be secondary factors, at least initially, in subjects with large extruded fragments. In subjects with smaller disk herniation or in those with chronic disability, these factors may indicate a higher risk of treatment failure.