---
title: 'Adjacent Level Disease'
type: 'lesson'
url: 'https://doc.social/courses/challenges-in-cervical-spine-surgery/adjacent-level-disease'
course: 'Challenges in Cervical Spine Surgery'
course_url: 'https://doc.social/courses/challenges-in-cervical-spine-surgery'
position: '1 of 4'
author: 'Dan Riew'
transcript: 'yes'
---

# Adjacent Level Disease

## Summary

_This lesson is a recording without a written summary._

## Transcript

1,920 words · 11 min · automatically transcribed (aws-transcribe) and not checked by a person; it may contain errors, particularly in names, drugs and dosages. The recording is the source.

[0:01] So let's talk about adjacent level uh problems, adjacent segment Pathology. This was a case that I did in 1996. And by the time 9 years later, we got another X-ray, you can see that the level above has broken down and the level below has broken down. Now, is that iatrogenic? Did I cause that by doing the Surgery? Or was that natural history?
[0:26] Well, there's increasing evidence that this is due to the natural history and very little of it is actually due to what we do as surgeons.
[0:36] There's data looking at anterior cervical fusion versus foraminotomy, arthroplasty versus ACDF. There's kinematics data, fusion data, etc.
[0:46] So, this is an uh, uh, this is a paper that Henderson uh published in neurosurgery back in 1983. He looked at 846 foraminotomy patients and found that there was about a 1.9% average annual incidence of radiculopathy that developed in these patients.
[1:05] And that the surgical rate for adjacent segment Pathology was about 3%. So in foraminotomy patients, he found that about 3% of the patients needed Surgery every year, and that's roughly comparable to the percentage of patients who need Surgery after doing a fusion.
[1:27] This is the Heerkowitz paper in Spine in 1990 and it was a prospective comparison of ACDF versus foraminotomy for a herniated disc. And they found that adjacent level radiographic changes occurred after ACDF in 41% of the cases versus with a foraminotomy, 50% of the cases. So again, when you look at X-rays, there doesn't seem to be much of a difference between the patients that you fused versus the patients you did a foraminotomy on.
[1:56] Suggesting that again, it's all due to a natural history as opposed to the fusion operation. And then we look at all the arthroplasty data that's come out and uh does a total disc replacement lower the risk of radiographic adjacent, so just X-ray changes or does it change the clinical adjacent segment Pathology uh when you compare it to fusions?
[2:22] And there's a whole lot of data on this now and there are a lot of prospective studies that have been done. And when you look at the clinical adjacent segment pathologies after a total disc replacement versus an ACDF, the reoperation rates for both is between about 1 and 5% per year. There is not that much of a difference.
[2:42] This is the seven-year follow-up and they did notice in this uh study of uh the ProDisc C that there was about an 11% difference at 7 years. This is the Prestige LP and again, initially they didn't find much of a difference, but later on they found about a 7% difference in the adjacent segment, uh, reoperation rate.
[3:03] This was a study of long-term prestige at two levels. And again, there was about a 10% difference in the reoperation rates. But when you look at all of the cervical arthroplasties, some have found that there are differences and some have found that there are no differences in adjacent segment Pathology rate. And a meta
[3:21] Analysis, 3 said, yeah, there is a difference and 1 said there wasn't. And even when you look at these differences, they're not huge, 3 versus 5%, 3% versus 8%, 5 versus 74 versus 7. So there is a difference but not that great of a difference. Um, and this is a paper that I, uh, was a one of the co-authors on that was just published in Neurosurgery in 2019.
[3:47] And what we found was that yes, there does appear to be a difference with the Brian, the reoperation at the adjacent level was about 10%. With the ACDF it was about 16%. So there's about a 6% difference at 10 years. Now, there wasn't a statistically significant difference. If you notice the P value is 0.1.
[4:09] So we combined it with the 7-year data from the Prestige and only then could we find that there was a 7 versus 12% difference. That's only a 5% difference in the adjacent level reoperation rates at between 7 to 10 years. So even in that long period of time, there's only a small amount of difference. And then you have to look at what the problems with these prospective randomized control studies are.
[4:34] So in the United States, these patients were recruited and they were told, you'll either get the artificial disc or you'll get the fusion. You won't get to decide, the surgeon doesn't get to decide, a computer will decide for you what you get.
[4:49] So when a patient got the artificial disc, they felt like, yes, I won the lottery. I'm so happy I got the artificial disc. And the patients who got the fusion said, oh, I got the fusion, and some people actually said, I'm not having Surgery, forget it. I wanted the artificial disc and if I can't get it, I'm gonna go somewhere else and just get the artificial disc.
[5:10] And uh so when the next level broke down, the patients who had the ACDF realized, you know what, I had the fusion and it was a great operation. I felt great. My neck range of motion is excellent. I really didn't lose any motion, so when they needed Surgery at the next level, they said, sure, I'll get the ACDF. I don't have any problems with that.
[5:29] But when the patients who got the artificial disc were told, oh, you need Surgery at the next level, and in the United States, the artificial disc isn't approved yet, we have to do a fusion. They said, fusion? No, I enrolled in this study because I didn't want the fusion. I got the artificial disc. I love it. I don't want a fusion. I'm not having Surgery. So that accounted for some of the difference between the group that got the artificial disc and the ones that got the fusion.
[5:56] So when you look at that difference of about 6%, you have to understand that that difference also represents the fact that people who got the artificial disc did not want any more surgeries, and that may be why there's some of that difference.
[6:11] We did this study a number of years ago on survivorship analysis and we found that laminoplasty has the lowest rate of needing Surgery for amyotomy. And then, uh, if you look at the anterior Operations, whether you're doing the artificial disc or the fusion, there wasn't a statistically significant difference.
[6:31] So it appears that there, it probably is a little bit of a difference, but if there should be a difference because of the fusion, you would notice a huge difference in this group of patients. So these were clippophile patients that we looked at. These were patients who were born with a fusion.
[6:49] And so you would think that if they were born with a fusion, that they would need Surgery at the adjacent level at a much earlier date than patients who did not have a fusion. So when we looked at the klipophile patients, there were 42 and 22 with klipophile syndrome and 44 controls. And we looked at how old are they when they have their first operation. If the klipophile fusion causes adjacent level problems early, then you would think that
[7:17] The klipophile patients would have their first operation at the next level when they're in their twenties. In fact, what we found is whether you have klippophile syndrome or you have a normal cervical Spine, the average age of needing Surgery was about 50.5 years. There was no difference between
[7:35] Congenitally autofused patients and patients who had a normal cervical Spine, suggesting again that a fusion does not add a lot of pressure at the next level, causing it to break down faster, causing you to need Surgery any more than uh anyone else.
[7:52] And then we looked at uh this study of uh radiculopathy versus uh uh my myelopathy at the next level. Um, this was a study that is most often quoted. It's Alan Hildebrand's study on adjacent level disease.
[8:07] And what he said was that the lowest risk of needing Surgery again is in somebody who's had a fusion at C4, 556, and 67.
[8:16] So if adjacent level problems are due to doing fusions, then the more levels you fuse, the more stress, uh, you put on the adjacent levels and you would think that they would break down faster. So a three-level fusion should have a greater risk of needing Surgery at the next level than a one-level fusion. In fact, that wasn't the case.
[8:37] A three-level fusion at 455667 had the lowest rate of needing Surgery again. The C7T1 and C34 rarely break down and require Surgery. And what it says is that these are the three levels that most commonly break down and require Surgery. So if you take care of those three, odds are you may never need to do Surgery on that patient again.
[9:00] And we um uh looked at also uh this study that was a part of an adjacent segment Pathology, uh, special issue, uh, a focus issue in the Spine journal. And what we found is that the Risk factors for the clinical adjacent segment Pathology, the breakdown at the next level, was if you were young. If you had a fusion adjacent to C5-6 or C6-7. So if you had a C4-5 or a C7T1 fusion,
[9:27] You're much more likely to need Surgery because 5667 are the most common levels to break down and require Surgery. So if you had a, a herniated disc at another level and you didn't take care of it, you're very likely to have, uh, uh, the need for Surgery. And if you had compression with a canal that was less than 13 millimeters, you're more likely to need Surgery.
[9:49] If you think about it, if you take your car in and you have a flat tire because your tire is bald, and you change that tire.
[9:57] And
[9:58] Two months later, you need the left front tire changed. You wouldn't say it was because I changed my right front tire that you now need to change the left. You say all the tires are exactly the same age. So if the right one is worn out, the left one is going to be worn out. If the C56 is worn out, the C6-7 is going to be worn out. All your cervical discs are exactly the same age. They've undergone the same amount of mileage, and it's just that some breakdown.
[10:25] Faster than others. And in the orthopedic world, if you had a Hip Replacement and your Knee broke down, you wouldn't say my Knee broke down because I got a new Hip Replacement. It's because your cartilage is made up of the same material and this, the Hip is the same age as the Knee. And here, this is a patient who's never had cervical Spine Surgery, but they've got breakdown at 455667. They have antrolisthesis of C7 on T1 and 3 and 4, and it has nothing to do with prior Surgery.
[10:55] This person has a virgin Spine, but it's because they obviously have broken down all of the levels because they're the same age. Now, that doesn't mean that you can't make it worse if you do a bad job, if you fuse somebody in kyphosis or you end up, uh, using a plate that's too long, you can make the next level break down a little bit.

## In this course

- [Next: Is Neck Pain a Surgical Problem](https://doc.social/llms/courses/challenges-in-cervical-spine-surgery/is-neck-pain-a-surgical-problem.md)
- [All lessons: Challenges in Cervical Spine Surgery](https://doc.social/llms/courses/challenges-in-cervical-spine-surgery.md)