A foraminotomy is a decompression surgery that is performed to enlarge the passageway where a spinal nerve root exits the spinal canal. The term foraminotomy is derived from the medical term for a hollow passageway—foramen. The latter half of the term foraminotomy—otomy—means to open.
During a foraminotomy, the spine surgeon removes bone or tissue that obstructs the passageway and compresses (pinches) the spinal nerve root, which can cause inflammation and pain. The nerve (neuro) passageways are called neuroforamen.
Neuroforamen: Location in the Spine
The neuroforamen are passageways that are naturally formed on either side (left, right) between an upper and lower vertebra. In between each upper and lower vertebra is an intervertebral disc. The height of the disc separates the two vertebrae and creates the size of the neuroforamen. The vertebral body and nerve structures of a single spinal segment are illustrated in Figure 1.
There are 31 pairs of spinal nerve roots that shoot off from the spinal cord and exit the spinal canal through the neuroforamen. Spinal nerve roots branch out to form an intricate network of nerves outside of the spinal canal called the peripheral nervous system (see Figure 2).
Nerve Compression: Symptoms and Causes
When the size of a neuroforamen is reduced, there is less room for the spinal nerve, which may cause nerve compression. Symptoms of nerve compression include pain, stiffness, numbness, tingling sensations, and/or weakness.
Since spinal nerves branch outward to form the peripheral nervous system, these symptoms may radiate into other parts of the body. For example, cervical nerve root compression can cause symptoms in the shoulders, arms, and hands. Lumbar symptoms may radiate into the low back, buttocks, legs, and feet.
Disorders that can cause nerve root compression include spinal stenosis, degenerative disc disease, a bulging or herniated intervertebral disc, bone spurs (osteophytes), and spondylosis (spinal osteoarthritis). Figure 3 illustrates these disorders. If you have a severe case of one or more of these conditions, your doctor may recommend a spinal decompression surgery, such as a foraminotomy. Spinal decompression surgery creates more space around the nerve, which may relieve pain. Foraminotomy is often combined with laminotomy and discectomy to decompress nerves.