Lumbar discectomy--percentage of disc removal and detection of anterior annulus perforation.

A prospective study was carried out to estimate the percentage of disc removal at the time of lumbar laminectomy and discectomy. Intraoperative discograms were obtained which afforded a method of calculating the percentage of disc removal. The technique permits localization of the level of discectomy and provides a means of detecting anterior annulus perforation intraoperatively, which we hope will reduce the morbidity of anterior annulus perforation. A comparison between the efficacy of disc removal (microdiscectomy vs. laminectomy) is also presented.