Surgery on the cervical spine is a delicate procedure. Usually such surgery is needed to relieve pain associated with a prolapsed or herniated disc. Disc disease causes it to fail and this makes the disc protrude and push on spinal nerves. The resulting pain usually happens as a result of pathology at the sixth and seventh cervical vertebrae. The treatment involves surgically removing the disc material and then stabilizing and fusing the vertebral bones together.
Anterior Approach
The anterior approach, commonly called anterior cervical discectomy and fusion or ACDF, is the more direct method for accessing the cervical intervertebral disc. A small incision is made on the front of the neck to reach the spine. The soft tissues such as the muscles, blood vessels and nerves are moved aside so that the vertebrae can be seen beneath. According to the Mayfield Clinic, special instruments are then used to remove either a portion or the entire intervertebral disc. Any bone spurs are also removed.
Posterior Approach
The posterior approach to cervical disc surgery is less frequently used. The surgeon makes an incision on the back side of the neck and the muscles and other soft tissues are moved aside to expose the back of the vertebral bones. Small pieces of bone are removed over the spinal roots exposing the nerve and the disc space. The part of the disc that has ruptured and is pressing on the nerve can be removed in order to relieve pressure on spinal nerves. Also, the bony space around the nerve root is enlarged to prevent future compression.
Discectomy
A partial or total discectomy means either part of the disk or its entirety is removed. Also, the disc can be replaced instead of removing it and fusing the two vertebral segments. This may preserve movement of the vertebrae which could prevent disc pathology at other vertebral levels. The Mayfield Clinic, however, states that this is not yet proven.
Finally, a minimally invasive microendoscopic discectomy can be performed which is a less traumatic approach. (ref 2) It starts with a small incision on the back of the neck. Instruments are inserted through the incision along with dilator tubes to enlarge a tunnel to the vertebrae. This exposes bone which can be removal in order to excise the portion of the ruptured disk pressing on the spinal root.
Fusion and Stabilization
Usually when a disc is removed a spinal fusion is required. This means two vertebrae need to be joined together to make one solid bone. The process necessitates packing small pieces of bone into the space formerly occupied by the disk. The bone is taken from the patient's hip or from cadaver donors. Recently, newer artificial material has been used. Over time, the body uses the grafted bone as a scaffold whereupon new bone is deposited naturally and which results in vertebral fusion. To achieve this, the bones must be kept immobile, or stabilized during the period of bone growth. The two vertebrae are stabilized using metallic hardware. These include screws, plates, rods and wires fixed to the vertebrae in order to hold the bones together firmly.
Recovery
Depending on the type of surgery that was performed, the patient usually needs to wear a cervical collar from one to 12 weeks. This allows the fusion to progress without mechanical stresses and movements which may hinder fusion. Pain usually resolves within six weeks. Return to work and normal activities should be carefully considered to prevent recurrence.
