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How to Prove Your Case for Lumbar Artificial Disc Replacement

Published April 23, 2020
| Written By SpineNation Editorial Staff  

Have You Been Told There’s No Evidence for Lumbar Artificial Disc Replacement? If So, Here are 8 Proof Points Worth Knowing



While lumbar artificial disc replacement surgery has been around for nearly 20 years, many health insurance providers have long argued that the procedure lacked adequate science to warrant approval. While coverage from these insurers has improved in recent years, some health plans still rebuff the advice of doctors and patient advocates who recommend lumbar artificial disc replacement surgery for the benefit of the patient’s quality of life and for the long-term benefit of the patient and the health plan in terms of repeat surgeries. While the cost of lumbar artificial disc replacement surgery is initially steeper, the benefits over time outweigh the cost.

Here are eight proof points you should know and understand to help you better advocate for lumbar artificial disc replacement surgery and how knowing these point can benefit you should you elect to take the path of appeal.


1. Protective Effect on Adjacent Segments

Preservation of motion in the lumbar spine with a lumbar artificial disc replacement (ADR) has been proven to have a protective effect on the low back segments adjacent to your index level intervention. What hasn’t been proven is the clinical relevance of this protective effect (i.e., reduction in additional spinal surgeries on adjacent levels years down the line). However, what we do know from the literature is that adjacent level degeneration (ALD), or also referred to as adjacent segment disease (ASD), both that present at the time of an intervention on a patient’s index level and new ALD (not present at the time of the index procedure), are curbed by placement of a lumbar ADR versus if a patient would have received a spinal fusion.

Some studies have demonstrated that the rate of progression of ALD following fusion is as high as 30% whereas the latest generation lumbar ADRs seem to lead to less than a 10% progression of worsening or new ALD at five years after surgery. What we do not know is of this 10% how many will manifest into additional surgeries. Surgeons theorize that we will start understanding the benefit at the 10- and 15-year time points when we normally see the impact of “fusion disease” rearing its ugly head. The problem with that is, there are no ongoing multi-center studies looking at this data at ten and fifteen years because of issues with patient retention and frankly the cost of running these long-term studies.

Many surgeons are tracking their own data out this long. For instance, the Texas Back Institute has started presenting their center’s 20-year data on ADRs. While single-center experiences are not as robust of data as multi-center FDA studies, it is the best we are going to have for these technologies. For now though, based on the multi-center studies, we know that less than 5% of Lumbar ADR patients will need additional surgeries within seven years of their first implant, which is pretty amazing.


2. Life of the Implant 

It’s reasonable that physician, payer, and patient stakeholders all want to understand how long the lumbar ADR implant will last once implanted. Spine surgeons have been implanting multiple generations of lumbar ADRs in the United States for 20 years. Surgeons are not seeing these implants, even the first generation implants, wear out. So why the hype about them wearing out?

The payers have used the concerns around “wear” in early generation artificial hip replacements coupled with the presumed difficult revisability of lumbar ADRs to object to the life of lumbar ADRs. While the in-patient life of a lumbar ADR beyond 20 years is not widely understood, very respectable biomechanic tests have shown that the newest generation implants will last under normal human wear conditions between 80 and 100 years. Compared to the artificial hip, this is about 13 to 14 times longer.


3.Maintenance of Motion Over Time

Do lumbar ADRs move for a while and then eventually find their happy place and freeze like a fusion? It might be an objection you hear. The newest and highest levels of evidence show this not to be the case.

In the randomized controlled trials, prior to their surgery, the average degenerative disc disease (DDD) patient had 6.6 degrees of flexion/extension range of motion. Five years after their initial implantation there had been no clinically or statistically significant drop-off in motion. The average patient had 6.1 degrees of range of motion (ROM). This means that through five years these implants are giving DDD patients something a spinal fusion cannot—enough preserved motion to ward off adjacent segment disease (ASD).

In the same studies that looked at the delay in ASD over time, the relationship of ROM to progression of ASD was examined. Zigler et al. reported that when motion is preserved in the lumbar spine, as lumbar ADR accomplishes, it also prevents progression of ASD.

Further, for every degree of flexion/extension ROM preserved by a lumbar ADR in the lumbar spine, a patient is that much less likely to have adjacent segment issues. For example, a patient who has 4 degrees of flexion/extension ROM at five years after surgery is much more likely to have ASD issues than a patient who has maintained 6.6 degrees of ROM.


4. Revisability of Implants

It is quite true that if there is a failure of a lumbar ADR that it is difficult to revise the ADR, with a few caveats. Lumbar ADRs do not fail often. In fact, at five years postoperative only 5% of patients who underwent a lumbar ADR will need a revision due to implant failure. The reason you will primarily get pushback on revisability of a lumbar ADR is because of the surgical approach used to implant lumbar ADRs to begin with.

Lumbar ADRs are implanted through a direct anterior approach, meaning, the disc is inserted through your stomach. The body reacts to this approach by developing scar tissue, which makes getting back into the anterior space difficult should something go wrong with the implant. That said, it’s definitely not impossible. It’s also not frequently needed.

The good news is that the research shows that if a lumbar ADR is going to fail, it often does early before the scar tissue is developed that causes these access issues. If for some reason a revision is required after scar tissue is a concern, most surgeons will lock the lumbar ADR down using screws through a posterior procedure and simply leave the ADR in place. So yes, a concern—but one that is not really thought through by objectors given the low revision rate and the early time periods that failure occurs in the rare instances where it does happen.


5. Device Failure

As previously mentioned, only 5% of patients that undergo lumbar ADR will need a revision due to device failure. However, what is a failure anyway and what are the main reasons for them?

Device failures are defined by the investigators for the lumbar ADR devices as, “a revision, re-operation, removal or supplemental fixation at the index level.” Most failures occur early following surgery and the majority of the time are due to poor patient compliance to postoperative protocols (i.e., patients feel too good so they overdue it in the immediate postoperative period), poor patient selection by the surgeon, or incorrect sizing of the disc during the operation.

It is important for surgeons and patients to work together on expectations prior to, during, and after surgery.


6. Evidence Versus Fusion 

Specific patient populations are more likely to have better outcomes with lumbar artificial disc replacement than they are if they had a fusion. Disc replacement has been exhaustively studied in the single-level degenerative disc disease patient population and given that these discs are normally compared to spinal fusion in the studies, it also means that fusion in this patient population has been exhaustively studied.

There is a great meta-analysis available on this topic. It looks at all the patients who would have been candidates for a lumbar ADR but received a fusion because of the strict criteria of the FDA study they were enrolled in. In this pooled patient population, there was not a single outcome that favored fusion over lumbar ADR. Again, a very specific patient group but if you fall into this group, it defends why you should consider pushing your surgeon for a lumbar disc replacement.


7. Insurance Coverage

Coverage for lumbar artificial disc replacement was in a terrible place in 2015. However, with newer devices triggering the availability of new evidence since then, the rate of U.S. insurers now covering single-level disc replacement has more than doubled. If you have one of the main insurers it is likely that you have access to this procedure through your plan. Not sure if you have a plan that covers? Check out this post for more information on the insurance landscape.


8. Multi-Level Procedures Outside of FDA Indications

The medical community relies on the manufacturers to open insurance pathways for coverage and payment and because, up until recently, manufacturers couldn’t promote multi-level indications (ProDisc-L received FDA approval for a 2-level indication on April 10, 2020). They also can’t help expand access to these procedures with insurers. As such, it would feel that the U.S. surgeon community is behind in experience with these procedures. However, that’s quite possibly not the case. Multi-level lumbar disc replacement is just not accessible as often to patients because of insurers not understanding the potential benefits and thus not providing their patients with positive coverage to multi-level surgeries.

That said, U.S. surgeons do have the autonomy to perform these procedures if the patient has a means to pay for the operation. There is some evidence that is anecdotal on how these replacements perform when used at multiple levels. More studies are needed.

NOTE: If you are a patient with multi-level lumbar disc replacement and would like to share your story, please contact us.


Conclusion

As you can see, the evidence and the data support lumbar artificial disc replacement surgery as a first choice for most indicated patients. Not only are the implants safe and effective, but the quality of life outcome for patients undergo the lumbar artificial disc replacement surgery is better than those who undergo fusion.

If you want to learn more about the types of lumbar artificial discs available, read 6 Lumbar Artificial Discs, Their Features, and Clinical Proof Points. Here you’ll get to know more about artificial discs, their composition, technical specifications, and more. The more informed you are, the easier it is to advocate for better care from your health insurance provider.

Updated: April 23, 2020
Disclaimer

Information provided within this article is for educational purposes and is not a substitute for medical advice. Those seeking specific medical advice should consult his or her doctor or surgeon. If you need to consult with a specialist, you may be able find a health care provider in our Specialist Finder. SpineNation does not endorse treatments, procedures, products or physicians.


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