Both ACDF and anterior cervical disc replacement have been shown to have favorable clinical outcomes, meaning that successful results from both types of surgery can be expected in more than 90 percent of people with single-disc disease. Cervical disc replacement has been shown to have at least equivalent results to ACDF in relieving neck pain, arm pain, patient function, and satisfaction, and with no increase in perioperative complications.5–9 These results currently reflect 4 to 7 years of follow-up in FDA-approved studies.
An ACDF is the most common operation for treating patients with symptoms related to a degenerative or herniated disc in the neck. This procedure consists of removing the problematic disc entirely, replacing it with an implant, and laying down bone to allow a fusion to take place.
Learn more: ACDF: Anterior Cervical Discectomy and Fusion
Possible Benefits of Cervical Artificial Disc Replacement
Artificial cervical discs accomplish the same clinical objectives as the traditional ACDF surgery in terms of providing pain relief and function. There are also several potential benefits:
No risks related to bone graft and bone graft healing
Unlike ACDF, no bone graft is needed for a cervical artificial disc surgery, so it does not include the related potential complications. The most common potential complication in using bone grafts for ACDF is the potential of the bone graft to fail to heal, resulting in a non-union, or pseudarthrosis, which may require another fusion operation. Though relatively rare, there are also other potential complications related to bone graft, such as potential ongoing pain from the patient's pelvis where the bone graft is harvested (if the patient's own bone is used).
While the above risks are always possible with an ACDF, they can be mitigated or lessoned through a variety of means, such as with choice of implant, surgeon technique, as well as other factors.
Fewer hardware-related complications
Though relatively rare, there are potential complications related to the implants used in ACDF. One study showed that artificial cervical disc replacements carry a lower chance of needing a repeat surgery due to implant problems.10 These study results have the caveat that longer-term studies are not available for artificial cervical disc replacement, as it is a relatively newer surgery.
While post-operative swallowing difficulties are reported in both types of surgery, one study has shown they resolve at a more favorable rate in cervical disc replacement than in ACDF.11
Possible reduced risk of adjacent segment disease
Studies have shown that by fusing a segment of the spine, the levels of the spine above and below the fused area are forced to absorb more load since there is no longer any intervening motion shock absorption. These adjacent levels may wear out and become symptomatic for some ACDF patients within ten years of surgery. This is called adjacent-segment disease.
Artificial discs have been shown to maintain (but not increase) range of motion postoperatively.7,8,12 Theoretically, this should reduce load transfer and degeneration of the adjacent discs.
While an artificial disc lessens the risk of adjacent-segment disc degeneration or disease seen on X-rays at 4 to 5 year follow-up,6,9 it remains unclear at this stage if the risk of repeat surgery for adjacent segment disc disease is reduced with cervical disc replacement versus ACDF. More study is needed to further determine if and how much adjacent-segment degeneration is a factor in ACDR results.
In This Article:
- Artificial Disc for Cervical Disc Replacement
- Indications for an Artificial Cervical Disc
- Cervical Disc Pathology and Artificial Disc Surgery
- Considerations for a Cervical Disc Replacement Surgery
- Artificial Disc Vs. Anterior Cervical Discectomy and Fusion
- Surgical Procedure for Cervical Disc Replacement
- Cervical Disc Replacement Surgery Video
Possible Unique Risks of Cervical ADR
As a newer technology, one of the main risks that accompany artificial cervical discs is not knowing how long they will last and if a reoperation will be needed at some point in the future. At 4- to 5-year follow-ups, repeat surgery is required in 3 to 4 percent of patients who have undergone cervical disc replacement.5-8
Rates of repeat cervical ADR surgery appear to be similar to that of total hip replacement. While the cervical artificial disc bears less weight than an artificial knee or hip joint, it is possible that the synthetic neck joint will also wear down over time and may need to be replaced at longer-term follow-up.
Another unique risk of cervical artificial disc surgery is that it is possible that these synthetic discs may at some point be recalled or have unanticipated problems. This is true of any relatively newer implant or surgery.
The bottom line is that both ACDF and cervical artificial disc replacement have relatively good results and relatively few known risks.
- Sasso RC, Anderson PA, Riew KD, Heller JG. Results of cervical arthroplasty compared with anterior discectomy and fusion: four-year clinical outcomes in a prospective, randomized controlled trial. J Bone Joint Surg Am. 2011;93(18):1684-1692. doi:10.2106/JBJS.J.00476.
- Hisey MS, Bae HW, Davis R, et al. Prospective, Randomized Comparison of Cervical Total Disc Replacement versus Anterior Cervical Fusion: Results at 48 Months Follow-Up.; 2014. doi:10.1097/BSD.0000000000000185.
- Burkus JK, Traynelis VC, Haid RW, Mummaneni P V. Clinical and radiographic analysis of an artificial cervical disc: 7-year follow-up from the Prestige prospective randomized controlled clinical trial. J Neurosurg Spine. 2014:1-13. doi:10.3171/2014.6.SPINE13996.