Anterior Cervical Discectomy and Fusion
Indications for surgery:
The most common indication for ACDF is degenerative cervical spine disease that is aging and wear and tear of the cervical spine. This wear and tear also known as degenerative disc disease causes compression on the spinal cord or the nerve roots manifesting via multiple mechanisms including disc, osteophyte or shrinkage of the spinal canal (stenosis).
Other indications include traumatic injury to the neck through the disc with or without the involvement of facet joints. This may present in the form of fracture, subluxation, or dislocation of the spine. These injuries may present with cervical radiculopathy in the form of tingling, numbness, pain in the upper extremities. They may also present with severe spinal cord compression with quadriplegia leading to complete loss of power as well as sensation in all muscles of the extremities below the level of involvement.
These may present in the form of radiating neck pain, tingling, numbness, weakness in either extremity. It may also present with or without the involvement of balance, bowel or bladder. Patients with wear and tear usually do well with conservative treatment with the use of medications, physical therapy with or without cortisone injections.
Rarely, the patients with cervical spine disc causing compression on the spinal cord of the nerve roots may need urgent surgery without a trial of conservative management especially in cases who develop rapidly worsening neurological status, involvement of bowel or bladder, or balance with worsening. This is to prevent further worsening of neurologic status, with the hope of recovery of the deficit that has already been there.
ACDF can be performed at one or multiple levels depending on the requirement and indication. The surgery is done usually through a transverse incision on the front of the neck onto the one side with careful dissection and retraction of vital structures. The vital structures include food pipe, windpipe as well as major vessels of the neck along with the nerves. The level of the spine to be operated is checked with the use of imaging during the surgery.
Once the level is confirmed, the disc is removed thoroughly all the way to the back. The compression over the spinal cord and/or nerve roots is removed with thoroughness. Once the compression is removed, space is filled with the spacer. This spacer can be in the form of allograft cadaveric bone or metal or polymer cage. Once space is filled, it is usually bridged with the use of a plate and screws.
A similar procedure of cleaning the disc and filling it with the graft can be performed simultaneously at multiple levels. The spine is stabilized thereafter by the use of a plate and multiple screws. The final result is checked with imaging during the surgery.
The patients usually stay in the hospital for 2 to 4 days and are sent home in most instances. Occasionally, the patient who is weak may need to go to the rehabilitation center for recovery. It is expected that the pain is relieved after the surgery. Tingling and numbness may take some longer time to be relieved.
Weakness may also take some time to recover after the surgery. The patients are usually in a collar and are allowed to mobilize under supervision. They are allowed to all activities of daily living. They are usually seen in the office within 2 weeks after the surgery. Physical therapy may be required for optimal recovery.
Risks and complications:
As with all other surgeries, cervical spine surgery is also associated with certain risks and complications. These include injury to nearby nerves and vessels, swallowing issues, hoarseness of voice, injury to food pipe or windpipe, injury to the spinal cord or nerve roots causing temporary or permanent worsening of symptoms, failure of the implant, cage, need for reoperation, need for augmentation of fixation from the back.
Systemic complications include blindness, blood clots in the legs, neurological, pulmonary, cardiac complications, even death.
ACDF is one of the common surgeries of the cervical spine with excellent results. The patients usually recover well after the surgery. The fusion usually happens over a span of 3 to 4 months and the patient is able to perform all activities of daily living right from the first postoperative day. The patient can return to the pre-surgery level of activity at 2 to 4 months depending on the type of job the patient is involved in. In skillful hands, cervical spine surgery is a relatively safe surgery with excellent results.