The first artificial disc replacement in the U.S. was performed in 2000, but the technology has come a long way since then, with many surgeons predicting that the procedure will one day overtake spinal fusion as the standard of care.
Ten things to know:
1. Originating in Europe more than 30 years ago, Scott Blumenthal, MD, of Texas Back Institute in Plano, engaged in extensive research before performing the first artificial disc replacement in the country in 2000. Now, the Center for Disc Replacement at Texas Back Institute performs about 400 artificial disc replacements annually.
2. By 2026, the artificial disc market in North America is projected to exceed $2.9 billion, up from $874.1 million in 2019, according to Graphical Research. Cervical disc replacement is projected to see a particular surge in surgeon adoption as the demand for minimally invasive procedures continues to grow.
3. The Prestige LP, M6 and Prodisc-C are among the most common cervical discs and have long-term data showing their efficacy. Todd Lanman, MD, a spine surgeon in Beverly Hills, Calif., said surgeons are beginning to use artificial disc replacements for more procedures and he sees them becoming part of his revision strategy in the future.
"I believe fusion will be considered archaic, particularly cervical, because the data is so clear that ADR is superior to fusion in almost every outcome measure," according to Dr. Lanman. "Over a 10-year follow-up period re-surgical rates are half as much, so you're going to see new artificial discs created with even better designs and functionality, and surgeons are going to more rapidly move toward artificial discs. Many surgeons, particularly on the East Coast, still fuse a lot of patients. I think more disc replacements are done on the West Coast with people living more active lifestyles in a better climate."
4. Orthofix posted three- and four-year preliminary outcomes from its M6-C artificial cervical disc single-level clinical trial in May. Three insights from the study:
- Patients treated with M6-C "continue to have statistically significant benefits at three and four years" compared to anterior cervical discectomy and fusion patients, according to Frank Phillips, MD, who said this data is important "as it demonstrates the positive results originally reported in the study have been maintained through four years."
- At three years, M6-C patients had a mean Neck Disability Index score of 10.9, compared to 17.2 in the ACDF group.
- The mean Neck Disability Index for M6-C patients at four years was 10.3, compared to 19.2 for the ACDF group.
5. In February, NuVasive acquired Simplify Medical and its Simplify Disc for spinal arthroplasty in a $150 million deal. The device is supported through an FDA investigational device exemption for level-1 indications and is one of three artificial discs approved for two-level cervical total disc replacement.
6. Brian Cole, MD. Englewood (N.J.) Spine Associates: I think cervical disc replacement is becoming the standard of care for treating degenerative cervical disease now. In my own practice, I perform many more replacement surgeries than fusions. This is primarily because of the outstanding clinical results in terms of pain relief, return to function and patient satisfaction. Today we wouldn't think about fusing a knee or hip, so why are we fusing spines that aren't unstable?
7. Lali Sekhon, MD, PhD. Reno (Nev.) Orthopedic Center: I think cervical arthroplasty will continue to grow. I've been involved with cervical arthroplasty since 2000 and the original indications still stand: soft disc herniation, one to two levels with less than 50 percent loss of disc height for concordant radiculopathy or myelopathy, in the absence of facet disease. Correction of deformity, its place in the aging population (average age in most [investigational device exemptions] was early 40s), use for severe spondylotic disease are still issues. There will always be a place for spinal fusion. Material choices for fusion may fill the gap between arthroplasty so that different stiffness implants can be used. With the plethora of devices available, it's not so much which device is used (they all work in the forgiving cervical spine), it's patient selection. Lumbar arthroplasty may be revisited by lateral approaches.
8. Colin Haines, MD. Virginia Spine Institute (Reston, Va.): I firmly believe that motion-preserving spinal implants, most notably including cervical and lumbar disc replacements, will continue to grow over the next few years. Although the indications for disc replacement are more specific than spinal fusions, more than half of my cervical surgeries are disc replacements. Because the literature on cervical disc replacement is so clear, I do see more potential for growth and advancement in lumbar disc replacement. As the devices improve and data emerge on their longevity, lumbar artificial disc replacement surgery will become more common. However, I don't think it will ever eliminate spinal fusion surgery. Instability, sagittal balance mismatch and scoliosis will be better addressed with stability, which is what spinal fusions achieve. Regardless, the future brings great promise for artificial disc replacement with the continued evolution of this innovative technology.
9. Adam Shimer, MD. UVA Health (Charlottesville, Va.): There will undoubtedly be an increase in use of cervical disc arthroplasty relative to ACDF over the next five to 10 years. With that said, this shift will be evolutionary as opposed to the historical revolutionary explosion of low-friction hip and knee arthroplasty. Hip and knee fusions are pretty terrible whereas ACDF is a darned good procedure. I believe three key facts limit rapid, widespread transition to cervical disc replacement:
1. ACDF is a good surgery with predictable outcomes and a long proven track record.
2. There is more to 'think about' when choosing to do CDR. Just look at the FDA IDE inclusion criteria: DEXA scans, motion evaluation, no prior anterior or posterior surgery, no facet arthropathy.
3. The unknown as to what happens to CDRs 10, 20, 30 years down the line. These are being used in younger patients and we just do not know the longevity of these devices.
With increased use of CDR over the next five to 10 years we will see papers about not only the positive outcomes, but also more reports of complications and limitations.
10. Adam Bruggeman, MD. Texas Spine Care Center (San Antonio) and CMO of MpowerHealth (Addison, Texas): The future of disc replacement will depend on studies looking at more commonly performed surgeries, such as those on patients with prior fusions at other levels and those with multiple levels that need to be performed. Over the next five to 10 years, I see further adoption of disc replacement as well as additional studies looking at more common situations seen in day-to-day practices. I also anticipate implant designs will adjust for these evolving indications to include multiple options to address stability as well as endplate variations.