SURGERY FOR HERNIATED LUMBAR DISKS - A LITERATURE SYNTHESIS

Objective. To assess the risks and benefits of surgery for herniated lumbar discs (discectomy) and to evaluate the methodologic quality of the literature. Design: Literature synthesis. Study selection and data analysis: A structured MEDLINE search identified studies of standard, microsurgical, or percutaneous discectomy. Eligible studies had adult subjects, sample sizes of greater-than-or-equal-to 30, clinical outcome data for greater-than-or-equal-to 75% of patients, and follow-up of greater-than-or-equal-to 1 year. Summary rates of successful outcomes, reoperations, and complications were obtained by a random-effects logistic regression model. Methodologic quality was assessed using established study design criteria. Results: Eighty-one studies met inclusion criteria. Most had substantial design flaws and/or omitted important clinical data. Randomized trials of standard discectomy showed better short-term sciatica relief following surgery; 65% to 85% of patients reported no sciatica one year after surgery, compared with only 36% of conservatively treated patients. No data from randomized trials were available for microdiscectomy or percutaneous discectomy, although most outcomes appeared comparable to those of standard discectomy. Approximately 10% of discectomy patients underwent further back surgery, and rates increased over time. The rate of serious complications, including death and permanent neurologic damage, was less than 1%. Conclusions: Most studies were poorly designed and reported. Standard discectomy appears to offer better short-term outcomes than does conservative treatment, but long-term outcomes are similar. Discectomies are relatively safe procedures, though reoperations are common and increase over time. Decisions for elective surgery must balance faster pain relief against the risks and costs of surgery.