The spinal column is composed of 33 bones (called vertebrae) spanning from the base of the skull to the pelvis. Each vertebra has a round, solid body and a bony arch. The spinal cord runs through the hole between the arch and the body of the vertebra and is thus protected by bone on all sides.
A pair of spinal nerves (one on the right and one on the left) runs out between every vertebra. Soft intervertebral disks separate the bodies of the vertebrae, and the arches are connected to one another through joints called facets.
The part of the spine in the neck is called the cervical spine and consists of 7 vertebrae and 8 pairs of spinal nerves (called C1 to C8 for cervical nerves 1 through 8). The two most common problems people have with the cervical spine are disk herniation and stenosis.
Normally a vertebral disk has a fibrous outer "rind" and a soft interior, somewhat like a thick-skinned orange. When a disk herniates, the soft inside material squeezes out through a break in the rind and can pinch the nerves as they exit the spinal column. This will cause pain and sometimes weakness and numbness in the neck and arm.
Spinal stenosis occurs when the facet joints develop arthritis and start to grow excess bone around them (a typical response of a joint to arthritis). The extra bone narrows the space through which the spinal nerve exits the spinal column. This can lead to weakness and pain in the neck and arms.
By physical examination, a doctor (usually a neurologist, orthopedist, or neurosurgeon) can often determine the exact location of the trouble. The physician will test sensation, muscle strength and reflexes, and perform a number of other special tests to determine where the problem lies.
The treating doctor will also usually order X-rays and an MRI, which will help confirm the diagnosis and will help the physician develop an appropriate treatment plan.
Other less common conditions that can cause problems in the cervical spine include fractures, tumors, and infections.
The specific surgery depends on the exact nature of the problem. The surgery is conducted while the patient is under general anesthesia (unconscious and pain-free).
If there is a single herniated disk, then the disk may simply be excised through an incision either through the front or back of the neck.
If there is more than one disk that needs to be excised, then the spine usually needs to be fused to keep it from becoming unstable. For surgery from the front that means that bone is placed in the space where the disk was removed and plates are screwed into the vertebrae to keep them from moving. Rods are sometimes used to connect the vertebrae if the surgery is done from the back.
Spinal stenosis is a more difficult problem to treat and generally requires more extensive surgery. The spinal nerves and cord need to be decompressed and this can again be done from either the front or the back. Again, if there is enough bone taken away that the cervical spine becomes unstable, it will be necessary to fuse the remaining bone together with bone and plates, rods, or metal cages. The bone may be taken from the patient's body, usually from either the hip or the lower leg.
