Disc replacement, the Total Posterior Spine System (TOPS) and other motion-preserving options have given spine surgeons more ways to treat degenerative disease without fusing a segment. Four surgeons connected with Becker’s to share whether that has changed how they choose between fusion and motion preservation, and whether patient demand has outpaced the evidence.
Editor’s note: Responses have been lightly edited for clarity and length.
Question: Are spine surgeons shifting from fusion as the default treatment toward motion preservation, and is patient demand for motion preservation running ahead of the evidence?
Tan (Dan) Chen, MD., Orthopaedic Spine Surgeon and, Assistant Professor of Orthopaedic Surgery at, University of Virginia School of Medicine (Charlottesville):
“I don’t see motion preservation as replacing fusion as a default, but rather the technology expands the options we can offer appropriately selected patients. Fusion remains the right operation for many patients with end stage pathology, particularly those with instability, deformity, significant facet disease, or other pathology where preserving motion would not be appropriate.
In my practice, the decision is driven much more by patient expectations, the underlying anatomy and pathology than by age alone. For example, disc arthroplasty can be a very attractive option for appropriately selected patients with symptomatic disc disease and preserved facet joints. Similarly, TOPS may offer an option for selected patients with lumbar stenosis and posterior pathology who otherwise might have been candidates for fusion. In some cases, a more comprehensive 360-degree motion-preservation strategy may be appropriate, combining a TOPS system with disc arthroplasty to address both anterior and posterior pathology while maintaining motion. I’m also particularly excited as 3Spine develops its all-posterior arthroplasty technology, which could further expand the ability to preserve anterior motion without requiring an anterior approach.
I think patients are increasingly trying to avoid the “f-word,” fusion, when there may be a reasonable way to preserve motion without compromising the goals of surgery. That doesn’t mean fusion is going away, or that we should avoid it when it is clearly indicated. Rather, we’re entering an era where surgeons have more tools to individualize treatment. The goal isn’t to avoid fusion, it’s to avoid unnecessary fusion.
At the same time, patient enthusiasm can sometimes move faster than the evidence. Motion-preservation technologies should not be viewed as universal fusion avoidance solutions. Careful patient selection and a good understanding of the limitations of each technology are critical, and we still need longer-term data to determine how consistently preserving motion translates into better clinical outcomes.
To me, spine surgery is moving away from a one-size-fits-all philosophy. We’re increasingly able to match the operation to a patient’s specific pathology while preserving as much normal anatomy and function as reasonably possible.
Alexander Chung, MD. Orthopedic Surgeon at Banner Health (Phoenix): Probably 50% to 60% of my practice involves endoscopic and/or motion-preserving approaches (including disc replacement), ALIF, lateral surgery, MIS TLIF and, on occasion, traditional open fusion. That probably shapes my perspective: My bias isn’t toward motion preservation or fusion. My bias is toward the least disruptive operation that reliably treats the pathology, and if motion preservation surgery is an option, that is generally what I recommend.
It comes down to what makes the most sense for that patient. I also think we define motion preservation too narrowly. We immediately think of disc replacement, but we shouldn’t forget about decompression alone. I would argue that decompression is the least invasive motion-preserving operation we have, particularly when it can be done minimally invasively or endoscopically. If I can treat the pathology while preserving the native segment and avoiding an implant altogether, that’s goal No. 1, and ultimately what I would want for my own spine.
That said, I’m not going to force motion preservation onto somebody with segmental instability, significant deformity, severe facet disease, poorer bone quality, or another clear indication for fusion. The goal should be to avoid unnecessary fusion, not to avoid fusion at all costs.
And frankly, the best motion-preserving surgery is no surgery at all. I tell patients all the time, as much as spine surgery has advanced, we still haven’t mastered the spine. There are patients with multilevel degeneration and nonspecific axial back pain where we simply don’t have a reliable surgical target. We have to be disciplined enough to tell those patients that surgery is unlikely in their best interest. That’s where we partner with therapists and interventional pain physicians, while counseling patients on appropriate spine care and setting realistic expectations about what surgery can and cannot accomplish.
It’s the whole picture (that decides the procedure): anatomy, pathology, instability, deformity, bone quality, age, physiology, activity level, and patient goals. Pure cervical radiculopathy is a good example. In the right patient, posterior foraminotomy, disc replacement and ACDF may all be reasonable, but each carries different trade-offs. Posterior decompression preserves the native disc and avoids an implant but may carry more risk of recurrent symptoms or index-level reoperation. Disc replacement preserves motion and appears to reduce adjacent-level degeneration and subsequent surgery compared with fusion, but you’re still placing an implant into a relatively young patient. ACDF remains extremely reliable, but you accept loss of motion and a meaningful long-term risk of adjacent-segment disease.
We now have encouraging disc-replacement data extending to 20 years, but those datasets remain limited compared with the decades of robust hip, knee, shoulder arthroplasty data. From those data, we know that eventually, articulating devices wear out. Therefore, 20 years sounds like long-term follow-up until you’re putting an implant into a 35-year-old. Ultimately, if several options are reasonable, I explain the trade-offs, and we make the surgical decision together.
I don’t necessarily think demand is running ahead of the evidence. I think sometimes patient perception runs ahead of the nuance. Patients may hear that someone did great with a disc replacement or poorly with a fusion and conclude that motion preservation is good and fusion is bad. Spine surgery just isn’t that simple. We also have to be discerning about the literature. In spine surgery, you can often find good studies supporting different approaches depending on the population, endpoint, technique, and follow-up. The evidence should inform surgical judgment, not replace it.
Ultimately, having a broad surgical toolbox allows you to let the pathology dictate the operation rather than making the pathology fit the operation you happen to do.
While I do believe the future of spine surgery should continue to prioritize minimizing unnecessary fusion and maximizing motion when appropriate, that should never supersede the more important goal: matching the least disruptive effective and durable operation — or sometimes no operation at all — to the right patient by prioritizing their needs, goals and expectations.
Alexander Crawford, MD. Orthopedic Spine Surgeon and Assistant Professor in the Department of Orthopaedic Surgery at the Icahn School of Medicine at Mount Sinai (New York City):For me it is neither a fusion-first nor a motion-preservation-first practice. For single and two-level cervical disc disease in an appropriate candidate, I present both disc replacement and fusion as very viable options and let the patient decide. The published data suggests there may be a slightly reduced, though not zero, rate of adjacent segment disease after arthroplasty. At the same time, disc replacements can fail in ways that fusions do not, and I remain somewhat cautious about the very long term. Wear debris or metallosis in the anterior neck, adjacent to the spinal cord, could prove a more serious problem than the same phenomenon around a hip replacement. We have encouraging longer-term results, but I do not consider that question definitively answered.
I would also add that motion preservation is a broader philosophy than the disc replacement-versus-fusion debate. In a myelopathy patient with congenital or multilevel stenosis, I frequently default to laminoplasty precisely because it decompresses the cord while preserving motion and avoids committing a patient to a three- or four-level fused construct. I apply the same thinking in the lumbar spine, where I am relatively conservative with hardware. Motion preservation, to me, includes every strategy that solves the clinical problem while fusing as little as possible.
For arthroplasty specifically, I follow the standard contraindications: significant facet arthropathy, osteoporosis or poor bone quality, segmental instability, kyphotic deformity, severe disc height loss and advanced spondylosis. When those are absent and the patient is a good candidate for either operation, it becomes a shared decision built around the patient’s priorities and risk tolerance.
Some patients do come in asking about disc replacement specifically, but in my practice it is still a minority. What I would emphasize on the evidence side is that essentially all of the 10-plus-year outcome data for cervical disc replacement comes from industry-sponsored FDA IDE trial cohorts and their extensions. That does not mean the results are wrong, but it adds a layer of appropriate skepticism when interpreting them, and it means the field would benefit from more independent long-term replication before declaring the question settled.
I do not currently offer the TOPS system myself, though I have a colleague in another state who does and has had good early success with it.
Ramin Raiszadeh, MD. Spine Surgeon at the Spine and Brain Institute of San Diego:
Absolutely, defaulting to it. I’m a huge believer in motion preservation technology — quicker recovery, less incidence for reoperations and less adjacent segment disease. Surgeries work best when performed on the right patient, at the right time with the right diagnosis. This is absolutely my default operation, unless significant sagittal instability (>4.5 mm lumbar, 3.5 mm in cervical) or coronal instability (>15 degrees Cobb angle), osteoporosis, significant kyphosis (>10 degrees). Obvious exclusions are cancer and malignancy.
Patient selection is key when deciding; that is absolutely what determines success. I think age is key, activity level is key. Understanding the patient’s expectations are key. Ideal age is less than 40, but have done off label in 50s, 60s for cervical and lumbar. Again, patients need to be informed, given the risk/benefit profile, and understand off-label use in some specific cases.
As long as the patient is well informed, I will perform disc replacement surgery on patients with severe disc collapse, facet degeneration and even hybrid surgery, i.e. 4 level neck disease (2 level ACDF, 2 level cADR — I do get work comp insurance approval); also 1 level ALIF L5-S1 for significant instability and discogenic disc disease at L4-5 where I perform an L-TDR. I have also done skip lesions — for example, ACDF C6-7, ADR C5-6, skip C4-5 and do an ADR at C3-4. Patients must be informed of off label use, i.e. indications outside of FDA’s approval guidelines and the potential for reoperations in any of these settings. In all of these scenarios, insurance authorization is always obtained.
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