Anterior cervical discectomy and fusion (ACDF) are a surgery to remove a herniated or degenerative disc in the neck area of the spine. The incision is made in the front of the spine through the throat area. After the disc is removed, a bone graft is inserted to fuse together the bones above and below the disc space. Your doctor may recommend a discectomy if physical therapy or medications fail to relieve your neck or arm pain caused by pressure on the spinal nerves. Patients typically go home the same day; recovery time takes four weeks.
(top view of vertebra) Degenerative disc disease causes the discs (purple) to dry out. Tears in the disc annulus can allow the gel-filled nucleus material to escape and compress the spinal cord causing numbness and weakness. Bone spurs may develop which can lead to a narrowing of the nerve root canal (foraminal stenosis). The pinched spinal nerve becomes swollen and painful.
What is an anterior cervical discectomy & fusion (ACDF)?
Discectomy means “cutting out the disc.” A discectomy can be performed anywhere along the spine from the neck (cervical) to the low back (lumbar). The surgeon reaches the damaged disc from the front (anterior) of the spine through the throat area. By moving aside the neck muscles, trachea, and esophagus, the disc and bony vertebrae are exposed. Surgery from the front of the neck is more accessible than from the back (posterior) because the disc can be reached without disturbing the spinal cord, spinal nerves, and the strong neck muscles. Depending on your particular symptoms, one disc (single-level) or more (multi-level) may be removed.
After the disc is removed, the space between the bony vertebrae is empty. To prevent the vertebrae from collapsing and rubbing together, a spacer bone graft is inserted to fill the open disc space. The graft serves as a bridge between the two vertebrae to create a spinal fusion. The bone graft and vertebrae are fixed in place with metal plates and screws. Following surgery, the body begins its natural healing process, and new bone cells grow around the graft. After 3 to 6 months, the bone graft should join the two vertebrae and form one solid piece of bone. The instrumentation and fusion work together, similar to reinforced concrete.
Each type has advantages and disadvantages.
- Autograft becomes from you. The surgeon takes your bone cells from the hip (iliac crest). This graft has a higher rate of fusion because it has bone-growing cells and proteins. The disadvantage is the pain in your hipbone after surgery. Harvesting a bone graft from your hip is done at the same time as the spine surgery. The harvested bone is about a half inch thick – the entire thickness of bone is not removed, just the top half layer.
- Allograft bone comes from a donor (cadaver). Bone-bank bone is collected from people who have agreed to donate their organs after they die. This graft does not have bone-growing cells or proteins, yet it is readily available and eliminates the need to harvest bone from your hip. Allograft is shaped like a doughnut, and the center is packed with shavings of living bone tissue taken from your spine during surgery.
- Bone graft substitute comes from man-made plastic, ceramic, or bioresorbable compounds. Often called cages, this graft material is packed with shavings of living bone tissue taken from your spine during surgery.
After fusion you may notice some range of motion loss, but this varies according to neck mobility before surgery and the number of levels fused. If only one level is fused, you may have similar or even better range of motion than before surgery. If more than two levels are fused, you may notice limits in turning your head and looking up and down. Motion-preserving artificial disc replacements have emerged as an alternative to fusion. Similar to knee replacement, the artificial disc is inserted into the damaged joint space and preserves motion, whereas fusion eliminates motion. Outcomes for artificial disc compared to ACDF are similar, but long-term results of motion preservation and adjacent level disease are not yet proven. Talk with your surgeon about whether ACDF or artificial disc replacement is most appropriate for you.