Does everyone who has a fusion develop this?

No. Changes at the adjacent levels are commonly visible on later imaging, but visible change and symptoms are different things, and only a minority of patients go on to need further treatment there. The distinction matters, because a report describing adjacent segment degeneration is not by itself a problem.

Does disc replacement prevent it?

That is the rationale, and it is a well-reasoned one: not transferring the load should mean not loading the neighbours. Whether it prevents adjacent level problems for any individual patient over decades is a longer-term question the evidence is still answering. It should be described as a rationale rather than a promise.

If I already have a fusion, what can I do?

The usual things that help any spine: conditioning, maintaining strength and flexibility, managing weight, and avoiding nicotine. None of it is specific to adjacent segments, and none of it is a guarantee. What is worth doing is having new symptoms assessed rather than assuming they are the old problem returning.

Should this stop me having a fusion?

Not on its own. When a segment is genuinely unstable, fusion is the operation that addresses it, and declining it to avoid a future risk means living with a present problem. Adjacent segment stress is one cost among several, weighed against what the fusion is fixing.

condition

What Happens to the Discs Next to a Fusion?

Medically reviewed by Arash J. Sayari, MD · September 26, 2026

The short answer

A fused segment no longer contributes motion, so the levels above and below take up its share and carry more load. Over time those levels show more wear, and some patients eventually need attention there. How much of that is caused by the fusion and how much would have happened with age anyway is genuinely difficult to separate, and reasonable surgeons read the evidence differently. The added stress is real, and it belongs in the decision rather than being either dismissed or overstated.

The mechanics are straightforward

A spine shares movement across many segments. The neck has seven levels contributing to every turn of the head; the lower back has five carrying every bend.

Fuse one and it stops contributing. The motion it used to provide has to come from somewhere, so the levels immediately above and below do more, and carry more load doing it.

Nobody disputes that part. It follows from the mechanics.

Where it gets genuinely uncertain

What is disputed is how much of the wear seen at those levels years later is attributable to the fusion.

The difficulty is that the levels next to a fused segment were never a random sample. A patient who needed a fusion at one level frequently had degenerative change developing throughout, and those neighbouring levels would have continued to change with age regardless.

So when a study finds more degeneration next to a fusion, some of it is the fusion and some of it is the patient. Separating the two requires knowing what would have happened otherwise, which is exactly what cannot be observed.

Reasonable spine surgeons read this literature differently, and a page claiming the question is settled in either direction is overstating it.

Change on a film is not the same as a problem

This distinction matters to anyone reading their own follow-up imaging.

Degenerative change at the levels next to a fusion is commonly visible on later scans. Most of those patients have no symptoms from it, and only a minority go on to need treatment there.

So a report mentioning adjacent segment degeneration is describing an imaging finding rather than announcing a complication. Whether it matters depends, as always, on whether it explains anything the patient is actually feeling.

What this means for the decision

Two things, and they pull in opposite directions, which is why it is worth stating both.

Adjacent segment stress is a real cost of fusion, and it is the strongest argument for preserving motion where the anatomy allows. That is the reasoning behind cervical disc replacement in suitable candidates.

It is also not a reason to decline a fusion that is genuinely indicated. When a segment is unstable, or a slip is moving, fusion is the operation that addresses it. Avoiding a present problem because of a possible future one is not a good trade.

Where it fits in a consultation

If a fusion is being recommended, it is fair to ask what happens to the neighbouring levels and whether a motion-preserving option was considered for yours.

A good answer engages with the question rather than dismissing it, names the specific reason your anatomy points where it does, and does not promise that a replacement would protect the adjacent levels indefinitely. Nobody can promise that yet.

References

Medically reviewed by Arash J. Sayari, MD · September 26, 2026

This page is for general education and is not medical advice. It does not create a doctor-patient relationship, and it cannot account for the specifics of your own spine. For guidance about your situation, see a qualified physician. If you think you are having a medical emergency, call 911 or go to the nearest emergency department rather than waiting for an appointment.

Common questions

Does everyone who has a fusion develop this?: No. Changes at the adjacent levels are commonly visible on later imaging, but visible change and symptoms are different things, and only a minority of patients go on to need further treatment there. The distinction matters, because a report describing adjacent segment degeneration is not by itself a problem.
Does disc replacement prevent it?: That is the rationale, and it is a well-reasoned one: not transferring the load should mean not loading the neighbours. Whether it prevents adjacent level problems for any individual patient over decades is a longer-term question the evidence is still answering. It should be described as a rationale rather than a promise.
If I already have a fusion, what can I do?: The usual things that help any spine: conditioning, maintaining strength and flexibility, managing weight, and avoiding nicotine. None of it is specific to adjacent segments, and none of it is a guarantee. What is worth doing is having new symptoms assessed rather than assuming they are the old problem returning.
Should this stop me having a fusion?: Not on its own. When a segment is genuinely unstable, fusion is the operation that addresses it, and declining it to avoid a future risk means living with a present problem. Adjacent segment stress is one cost among several, weighed against what the fusion is fixing.