Extraforaminal Lumbar Disc Herniations – A Report of Four Cases

From July 1985 to December 1989, 204 patients were operated on for lumbar disc herniations at chang Gung Memorial Hospital. Four of them were diagnosed as extraforaminal disc herniations and the diagnosis was verified by operation. The incidence was 1.9%. Computed tomographic (CT) scanning can demonstrate the lesions precisely and can direct the surgeon in approaching the lesion sites. The clinical findings wer not much different from those of classic disc herniation. A little older population was noted with an average age of 48.5 years (46 to 52 years). Surgical approach via the intertransverse ligament is recommemded for extraforaminal disc herniations. It causes less trauma to the facet joint and isthmus. Late spinal instability might be prevented.