Anterior Cervical Discectomy
For patients whose pain does not improve with non surgical treatments, surgery may be necessary. An anterior (front) cervical discectomy is the most common surgical procedure to treat damaged cervical discs or to alleviate nerve pinching as in a disc herniation (herniated disc).
The treatment’s goal is to relieve pressure on the nerve roots or on the spinal cord by removing the ruptured disc. After a skin incision is made, only one thin muscle needs to be cut, after which anatomic planes can be followed right down to the spine. This procedure is usually done under microscopic visualization. The limited amount of muscle transection or dissection helps to limit postoperative pain. Sometimes the space between the vertebrae are left open. However, in order to maintain the normal height of the disc space, the surgeon may choose to fill the space with a bone graft.
Depending on the location of the herniated disc, the surgeon may make an incision either in the front or back of your neck to reach the spine. The technical decision of whether to perform the operation from the front of the neck (anterior approach) or the back of the neck (posterior approach) is influenced by many factors including the exact location of the disc herniation and the experience and preference of the surgeon. With either approach, the disc material is removed from the nerve, usually with good results.
Because removal of the herniated disc fragment from the front removes most of the disc in addition to the herniated portion, fusion is often recommended and performed at the same time. An alternative to anterior decompression in select cases of disc heriniation (radiculopathy) is decompression of the pinched nerve through an incision in the back of the neck (posterior decompression - foraminotomy).
1. Surgical approach
- The skin incision is about one inch and horizontal and can be made on the left or right hand side of the neck.
- The thin platysma muscle is then split in line with the skin incision and the plane between the sternocleidomastoid muscle and the strap muscles is then entered.
- Next, a plane between the trachea/esophagus and the carotid sheath can be entered .
- A thin layer of fibrous tissue that covers the spine can easily be dissected away from the disc space.
2. Disc removal
- A needle is inserted into the disc space and an x-ray is done to confirm that the surgeon is at the correct level of the spine.
- After the correct disc space has been identified on x-ray, the disc is then removed by first cutting the outer annulus fibrosis (fibrous ring around the disc) and removing the nucleus pulposus (the soft inner core of the disc). The dissection is often performed using an operating microscope to aid with visualization of the canal.
- Dissection is carried out from the front to back to a ligament called the posterior longitudinal ligament. This ligament can be gently removed to allow access to the spinal canal to remove any osteophytes (bone spurs) or disc material that may have extruded through the ligament.
The residual space can be replaced with bone. A bone graft is a small piece of bone, either taken from the patient’s body (usually from the pelvic area) or from a bone bank. This piece of bone fills the disc space and ideally will join or fuse the vertebrae together (fusion). It usually takes a few months for the vertebrae to completely fuse. In some cases, instrumentation (plates or screws) may also be used to add stability to the spine.
The expected outcome from decompression/fusion procedures of the neck is good. Surgery is very effective in reducing the pain in the arms and shoulders caused by a herniated cervical disc. However, some neck pain may persist.
- Significant improvement of arm pain:75-95%. Anterior discectomy results are similar to foraminotomy
- Strength improvement may take up to two years.
- Moderate improvement of neck pain: 60-90%
Patients will feel some pain after surgery, especially at the incision site. While tingling sensations or numbness is common, and should lessen over time, they should be reported to the doctor. Most patients are encouraged to be up and moving around within a few hours after surgery. Many patients are able to go home within a short period of time-sometimes as litle as 24 hours after surgery. After surgery, your doctor will give you instructions on when you can resume your normal daily activities.
Often patients are encouraged to maintain a daily low-impact exercise program. Walking, and slowly increasing the distance each day, is the best exercise after this type of surgery. Some discomfort is normal, but pain is a signal to slow down and rest.
Signs of infection like swelling, redness or draining at the incision site, and fever should be checked out by the surgeon immediately. Keep in mind, everybody is different, and therefore the amount of time it takes to return to normal activities is different for every patient. Discomfort should decrease a little each day. Most patients will benefit from a postoperative exercise program or supervised physical therapy after surgery.
In skilled hands, this is a very safe procedure. Possible reported risks and complications of anterior cervical fusion may include:
- Damage to the spinal cord (about 1 in 10,000)
- Graft extrusion
- Continued pain
- Adjacent disc disease
- Injury to the trachea or esophagus
- Difficulty swallowing- usually transient
- Hoarseness of the voice- usually transient
- Injury to the vertebral artery or carotid
The small nerve that supplies stimulus (innervation) to the vocal cords, the recurrent laryngeal nerve, will sometimes not function for several months after surgery because of retraction during the procedure, which can cause temporary hoarseness. Retraction of the esophagus can also produce temporary difficulty with swallowing (1 to 2 weeks). There is little chance of a recurrent disc herniation because most of the disc is removed with this type of surgery.