One Up or Down: Disc Herniation after Spine Fusion
Sometimes, surgery is needed for back pain. Two or more bones may be fused together to prevent movement at that level. This is called a spinal fusion. There are some problems that can occur after spinal fusion. Disc herniation is one of these rare problems.

The disc is a spongy material between each vertebra in the spine. It is encased in a protective material and held in place by ligaments and fibrous tissue. Injury or damage to any of these structures can cause disc herniation. The disc material pushes out of its normal space and can begin to press on the spinal cord or spinal nerves, causing low back and leg pain.

When two or more bones of the spine are fused together, movement between the fused bones stops. The segments just above and below the fusion have to move more than normal. This extra movement can cause wear and tear on the discs above and below the spot where the spine is fused. The result can be a disc herniation.

Anyone with a previous fusion in the low back can have a disc herniation later. Returning symptoms of back and leg pain after a fusion surgery should be checked by a doctor. This could be the first indication of disc herniation. Early treatment with physical therapy may help prevent surgery. In some cases, another surgery to treat the new disc herniation may be needed.
References
Stanley D. Gertzbein, MD, and Michael R. Hollopeter, PA-C. Disc Herniation After Lumbar Fusion. In Spine. August 15, 2002. Vol. 27. No. 16. Pp. E373-E376.