Is Lumbar Disc Replacement a Valuable Treatment for Degenerative Disc Disease?

31st Annual Meeting of the North American Spine Society Highlight

In 2004, the U.S. Food and Drug Administration approved total disc replacement (TDR) as a treatment for lumbar degenerative disc disease (L-DDD). But how valuable is TDR compared to more established or traditional procedures? During the 31st Annual Meeting of the North American Spine Society in Boston, Richard D. Guyer, MD, presented findings on costs and outcomes of total disc replacement (TDR) for lumbar DDD compared to spinal fusion.
Benefit versus cost on a scaleCollecting true, inclusive economic data for all parties impacted was the challenge of this study. Photo Source: “This [TDR] is certainly the trend in restoring motion and restoring normal sagittal alignment, which a disc replacement can do and a fusion cannot in all positions,” said Dr. Guyer, who is the co-founder of Texas Back Institute and co-director of the Center for Disc Replacement.

Dr. Guyer noted that medical advances almost always result in increased cost to the patient, provider, and payer (insurer). This is particularly the case when new devices, such as artificial discs, are introduced into the market.

The Challenge: Finding Clear Cut Cost Data

Collecting true, inclusive economic data for all parties impacted was the challenge of this study, Dr. Guyer said.

“If you think that MACRA [Medicare Access and CHIP Reauthorization Act] and all these other new regulations being put on us are hard to understand, it's even more difficult when you try to get to the bottom and determine a cost of what an individual operation would be,” Dr. Guyer said. “It's hard to get the cost to the patient, the cost to the employer, and the cost to society.”

In comparing costs of TDR and fusion, Dr. Guyer noted two items not addressed but important in the cost analyses:

  1. Return to work time and lost productivity costs
  2. Variation in results based on the outcome measures and the comparative treatments used

Despite these gaps, Dr. Guyer presented several studies investigating the cost of TDR.

2007 Study Comparing Disc Replacement to Fusions

In a 2007 study titled, An economic model of one-level lumbar arthroplasty versus fusion, co-authored by Dr. Guyer, the CHARITÉ artificial disc replacement device (no longer on the market) was compared to a standalone anterior lumbar interbody fusion (ALIF) with iliac crest bone graft, ALIF with INFUSE®, and instrumented posterior lumbar interbody fusion (PLIF). Dr. Guyer and his co-authors reviewed both the hospital cost and payer cost perspectives.

“For an economic model, we had to do a reasonable estimate of the treatment, and compare it to the current standard of care,” Dr. Guyer said. The economic model assessed costs—not charges—to the hospital and payer. And a reasonable estimate was based on available data and assumptions made when the data didn’t exist.

While obtaining the cost data for hospitals was difficult, the researchers were able to get clearer information on the payer side. “From the payer's perspective, it's actually a little easier because they know exactly what they pay out,” Dr. Guyer said.

Additional differences between hospital and payer perspectives regarded clinical outcomes. The clinical outcomes the hospital focused on included adverse events and complications, while the payer focused on absence of complications requiring any additional surgery.

  • Total Disc Replacement Value: Hospital Perspective

Through the data review, Dr. Guyer and his co-authors found disc replacement with the CHARITÉ device slightly more expensive to the hospital than an ALIF with iliac crest bone graft.

“Now, don't go away from here saying, ‘Oh, [TDR] is more expensive,’” Dr. Guyer said. “I don't know anybody today who will do an iliac crest bone graft for an anterior interbody fusion.”

Disc replacement was found to be cheaper than ALIF with INFUSE and an instrumented posterior fusion.

  • Total Disc Replacement Value: Payer Perspective

From a payer perspective, disc replacement was nearly equal in cost to the ALIF with bone graft, and it was less expensive than using the INFUSE or instrumented PLIF.

“We concluded that TDR was less expensive, and there may have been greater differences if we had the anterior/posterior data available at the time,” Dr. Guyer said.

Reviewing Other TDR Cost Studies

Dr. Guyer reviewed additional studies comparing costs of TDR and fusion for the treatment of DDD.

Study: Comparative charge analysis of one- and two-level lumbar total disc arthroplasty versus circumferential lumbar fusion

Results: Disc replacement was less expensive than a 360° fusion for one-level fusion but not significantly different for a two-level fusion.

Study: Lumbar spinal fusion versus anterior lumbar disc replacement: the financial implications

Results: TDR’s total hospital costs are similar to transforaminal lumbar interbody fusion (TLIF) or ALIF without BMP, but TDR was less expensive than TLIF or ALIF with BMP, and 360° fusion.

Study: National revision burden for lumbar total disc replacement in the United States

Results: The length of hospital stay is shorter and hospital costs are lower for TDR, but TDR had a greater revision rate.

Study: Cost comparison of total disc replacement vs. fusion in patients with insurance denial for disc replacement

Results: The TDR hospital bill was $66,000 versus $100,000 for the fusion. Disc replacement was also less expensive in the actual amount paid at $37,000 compared to $54,000 for fusion.

Study: Cost comparison of patients with 3-level artificial total lumbar disc replacements versus 360° fusion at 3 contiguous lumbar vertebral levels: an analysis of compassionate use at 1 site of the US investigational device exemption clinical trial

Results: It was significantly less expensive to perform a disc replacement versus a 360° fusion in patients with 3-level lumbar DDD.

Study: Cost effectiveness of disc prosthesis versus lumbar fusion in patients with chronic low back pain: randomized controlled trial with 2-year follow-up

Results: There was no difference in costs for TDR and fusion in some calculations, but TDR was less expensive than fusion when taking its lower re-operation rate into account.

Study: Cost-effectiveness of total disc replacement versus multidisciplinary rehabilitation in patients with chronic low back pain: a Norwegian multicenter RCT

Results: Study showed mixed results at a two-year follow up: TDR was cost effective when using EQ-5D for assessing quality-adjusted life years (QALYs) but not cost effective if using the SF-6D metric.

Study: Five-year adjacent-level degenerative changes in patients with single-level disease treated using lumbar total disc replacement with ProDisc-L versus circumferential fusion

Results: Adjacent segment disease in a five-year follow-up from the ProDisc-L was one-third of that with the fusion. If the adjacent level disc was normal before surgery, the disc had a 90% rate of remaining normal 5 years after TDR compared to a 71% rate with fusion.

Studies Suggest TDR More Valuable than Fusion

Overall, Dr. Guyer’s literature review supported the value of disc replacement for treating degenerative disc disease when compared to spinal fusion.

The studies Dr. Guyer reviewed demonstrated that TDR is less expensive, except for ALIF with autologous bone graft (which Dr. Guyer described as an outdated procedure). He also noted there is no published data to support TDR is more expensive than fusion.

“You all know when we perform fusions there are varying costs for the different interbody devices—the TLIF, OLIF, XLIF—you name it, plates, screws and combinations of bone graft materials,” Dr. Guyer said. “Then we have the posterior instrumentation—whether you use pedicle screws or facet screws—it all adds up.”

From a quality perspective, Dr. Guyer also referenced that TDR patients maintain their outcomes five years or longer, according to the FDA investigational device exemption (IDE) trials.

“There have been very, very low revision rates at the index level and adjacent level, which we're now seeing dramatically proven in the long-term cervical disc replacement data,” Dr. Guyer said.

Preliminary results suggest that patients with degenerative disc disease, who have TDR return to work quicker than fusion patients. Also, the five-year IDE data from six IDE studies found fewer TDR patients on long-term disability compared to fusions—TDR reduced societal costs related to lost work time and disability payments.

“There's a wide variation in methods, but regardless of method used, TDR is only similar to the outdated ALIF with bone graft but less expensive than modern fusions,” Dr. Guyer said.

To view additional meeting highlights from the 31st Annual Meeting of NASS, click here.

Updated on: 06/06/19
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