Background: Disc prolapse accounts for five percent of low-back disorders but is one of the most common reasons for surgery.
Objectives: The objective of this review was to assess the effects of surgical interventions for the treatment of lumbar disc prolapse.
Search strategy: We searched the Cochrane Central Register of Controlled Trials, MEDLINE, PubMed, Spine and abstracts of the main spine society meetings within the last five years. We also checked the reference lists of each retrieved articles and corresponded with experts. All data found up to 1 January 2007 are included.
Selection criteria: Randomized trials (RCT) and quasi-randomized trials (QRCT) of the surgical management of lumbar disc prolapse.
Data collection and analysis: Two review authors assessed trial quality and extracted data from published papers. Additional information was sought from the authors if necessary.
Main results: Forty RCTs and two QRCTs were identified, including 17 new trials since the first edition of this review in 1999. Many of the early trials were of some form of chemonucleolysis, whereas the majority of the later studies either compared different techniques of discectomy or the use of some form of membrane to reduce epidural scarring. Despite the critical importance of knowing whether surgery is beneficial for disc prolapse, only four trials have directly compared discectomy with conservative management and these give suggestive rather than conclusive results. However, other trials show that discectomy produces better clinical outcomes than chemonucleolysis and that in turn is better than placebo. Microdiscectomy gives broadly comparable results to standard discectomy. Recent trials of an inter-position gel covering the dura (five trials) and of fat (four trials) show that they can reduce scar formation, though there is limited evidence about the effect on clinical outcomes. There is insufficient evidence on other percutaneous discectomy techniques to draw firm conclusions. Three small RCTs of laser discectomy do not provide conclusive evidence on its efficacy, There are no published RCTs of coblation therapy or trans-foraminal endoscopic discectomy.
Authors' conclusions: Surgical discectomy for carefully selected patients with sciatica due to lumbar disc prolapse provides faster relief from the acute attack than conservative management, although any positive or negative effects on the lifetime natural history of the underlying disc disease are still unclear. Microdiscectomy gives broadly comparable results to open discectomy. The evidence on other minimally invasive techniques remains unclear (with the exception of chemonucleolysis using chymopapain, which is no longer widely available).