THE DISKECTOMY MEMBRANE (NERVE ROOT FIBROVASCULAR MEMBRANE) - ITS ANATOMIC DESCRIPTION AND ITS SURGICAL IMPORTANCE

The positive identification and protection of the nerve root is crucia l prior to addressing the disc during lumbar discectomy. We report her e our observation that there exists a membrane which lies immediately posterior to the annulus fibrosus at the level of the disc and connect s to the dura of the nerve root at that level. This is a constant anat omic finding during the approach to the disc, and we refer to it as th e ''discectomy membrane''. We found this tissue present at all lumbar levels of five fresh frozen cadaver spines. Its consistency varied fro m thin wisps of nearly transparent tissue to tissue strong enough to t ether the nerve root laterally.