There are a number of important factors when considering cervical artificial disc replacement (ADR) versus a traditional anterior cervical discectomy and fusion (ACDF) surgery. Depending on the patient’s unique situation, one procedure might have benefits over the other.
Comparing ACDF with Artificial Disc Replacement
An ACDF is the most common surgery for treating symptoms related to a degenerative or herniated disc in the neck .This procedure consists of removing the problematic disc entirely and replacing it with a bone graft (or bone graft substitute) to allow the adjacent vertebrae to eventually fuse together. ACDF is considered the gold standard for surgically treating cervical degenerative disc disease because it has been around for several decades longer and can treat more advanced spinal degeneration.
Cervical ADR differs from ACDF in that rather than fusing the adjacent vertebrae together, an artificial disc is inserted to maintain motion between the vertebrae. Some studies have shown that cervical ADR maintains more natural biomechanics within the cervical spine and places less stress on the discs above and below the surgical level than ACDF. However, more research is needed to determine the long-term results of cervical artificial discs.
Both ACDF and artificial cervical disc replacement tend to have favorable clinical outcomes. Successful results from both types of surgery can be expected in more than 70% of eligible patients with degenerative disc disease at a single spinal level. Cervical ADR has thus far demonstrated at least equivalent results to ACDF in relieving neck pain, arm pain, patient function, and satisfaction, and with no increase in surgical complications. These results currently reflect 5 to 10 years of follow-up in FDA-approved studies.1-3
Possible Benefits of Cervical Artificial Disc Replacement
For qualified patients, cervical ADR may accomplish the same clinical objectives as the traditional ACDF surgery in terms of providing nerve decompression and pain relief. There are also some potential benefits:
- No risks related to bone graft. Unlike ACDF, no bone graft is needed for cervical ADR surgery. One potential complication in using bone grafts for ACDF is the possibility of the bone graft failing to heal or fuse, resulting in a non-union. While relatively rare, there are other risks related to bone graft, such as the potential for ongoing pain from the patient's pelvis where the bone graft is harvested (if the patient's own bone is used).
- Quicker recovery. For both cervical ADR and ACDF, it is possible to return to light work and most daily activities within about a week of the procedure. Cervical ADR patients tend to be cleared for more strenuous activities about 6 weeks after the procedure, whereas ACDF patients are more likely to take 3 months or longer for the fusion to heal. Also, while postoperative swallowing difficulties are reported in both types of surgery, one study has shown they resolve at a more favorable rate in cervical disc replacement.4
- Possible reduced risk of adjacent segment disease. Artificial discs have been shown to maintain (but not increase) range of motion postoperatively. Theoretically, maintaining motion can reduce load transfer and degeneration of the adjacent discs. Some studies have shown that cervical ADR has a lower risk of requiring a repeat or second surgery compared with ACDF, but more long-term studies are needed.
It should also be noted that while these potential benefits exist, in many cases they might be small, especially when treating one level of spinal degeneration. For example, many people who have ACDF surgery have no complications with the bone graft forming a fusion, nor any significant problem with adjacent segment disease.
Possible Benefits of ACDF
Some potential benefits of ACDF include:
- Treat a wider range of patients. Many people are eligible to have an ACDF but not an artificial disc. A few examples include people who have facet joint degeneration, poor bone quality, cancer, or previous neck surgery.
- Fewer unknown risks. ACDF has been around decades longer than today’s artificial cervical disc options. While abundant data is available regarding the long-term safety and efficacy of ACDF, similar data is not yet available for cervical ADR. As a newer technology, one of the main risks of cervical ADR is not knowing how long the artificial disc will last, even though results thus far have been promising.
- Less complicated procedure. Cervical ADR is a more complicated procedure, with fewer surgeons trained in it than ACDF. If an artificial disc is the wrong size or incorrectly implanted, it could cause complications, such as continuing pain or the need for a revision surgery.
- More widely covered by insurance. While insurance carriers are increasingly covering cervical ADR surgery when it is deemed medically necessary, ACDF is still more commonly covered.
Making the decision between ACDF and cervical ADR commonly comes down to patient preferences and discussing the potential benefits and risks with the treating physician.