Extreme Disc Herniation
You may have heard of extreme sports. But have you ever hear of "extreme disc herniation?" That's a term used to describe a condition called extraforaminal lumbar herniation (EHL). Extra means outside, and foramen is a hole or opening. EHL refers to disc herniation in the lower spine that occurs in a spot just beyond where the spinal nerve goes through the opening in the bone.

Most disc herniations press against the nerve root before it leaves the foramen. Only about four percent of the patients with disc problems have EHL. Most of them occur at certain spots in the spine.
Surgeons who remove the disc fragment must pay attention to both the foramen and the herniation. The problem disc is located above the nerve it's pressing on. Doctors try to avoid removing bone from the vertebra. Loss of bone can cause the spine to become unstable.

These researchers in Italy report on their method for removing the disc without removing the bone or damaging nearby soft tissues. They use a tool with binocular magnification lenses. Another device called a retractor helps them move muscle aside without cutting it. This approach helps the surgeon operate in such a small space. The extraforaminal piece of disc is easily removed. Patients in this study all had good results. Most symptoms went away right away and everyone returned to work without any nerve pain. There were a few cases of persisting mild low backache.

In this report, the doctors carefully describe the steps they took in completing the surgery. They give the exact location of bone, joint, ligament, and muscle involved. The surgeon must move carefully between nerve and blood vessels to avoid damage there as well. Other doctors will find this helpful information when faced with a patient who has EHL. Knowing where and how to enter to get to the site is the key to this operation.
References
Ramundo Orlando Epimenio, et al. Extraforaminal Lumbar Herniation: "Far Lateral" Microinvasive Approach Retrospective Study. In Journal of Spinal Disorders. December 2003. Vol. 16. No. 6. Pp. 534-538.