Dear Dr. Lowell,
My doctor says I have spinal stenosis, and that’s what’s causing the pain which is in my back and my legs. We’ve tried different medicines and he sent me for physical therapy, but I still have the pain. Now he says I may need an operation. What would need to be done? I can’’t even walk a few blocks so I want something done, but I’m scared.
Your condition, spinal stenosis, is a narrowing of the spinal canal from bone spurs. The spurs cause the pain by pinching your nerves. The operation for spinal stenosis is called a laminectomy. In the areas where your nerves are compressed, I remove the arch of bone that covers the spinal canal. This bony arch is called the lamina, and its removal allows access to the nerves. Removing this bone is harmless. Your spine will work perfectly well without it. I then remove any and all debris that is squeezing the nerves. This can include bits of disk, thickened ligaments, and bony spurs. When done, all the nerves will be free and uncompressed, and the pain caused by their compression will dissipate. A laminectomy is about 85-90% successful in relieving your leg pain. Usually some back pain will persist after the operation. This is because I can free up the nerves, but I cannot cure the back arthritis.
In most patients with spinal stenosis, a laminectomy is all they need for relief. However, some conditions require something additional for best results: a fusion. I do this procedure at the same time as a laminectomy. Some of your own bone is harvested from a particular area on your pelvis that can spare it safely. This bone is placed between two or more levels of the spine, so that when it heals, the levels are fused together by a solid bridge of bone. This bridge eliminates most all motion between the vertebrae involved. When is a fusion necessary? When there is evidence of instability in the spine. An unstable spine can cause pain, and a fusion eliminates instability, relieving the pain. Another cause for fusion is a condition that may lead to instability later if a laminectomy is performed. In this case, a fusion is done to prevent future instability. Lastly, sometimes a patient’s spinal stenosis is so severe that, to cure it, the laminectomy must be more extensive than usual. This extensive bone removal can lead to instability later, and a fusion is done to prevent it. In this case, I may not know in advance whether or not a fusion is necessary, and I will have to decide that in the operating room.