Is Lumbar Fusion Surgery a Reliable Procedure?

Is Lumbar Fusion Surgery a Reliable Procedure?

Spine-health.com expert featured on Back Pain Radio

Modern lumbar fusion surgery is a very reliable procedure, provided it is done by an appropriately skilled surgeon for the right patients. Read what Peter Ullrich, Jr., M.D., an orthopedic spine surgeon in Wisconsin and Medical Director of Spine-health.com, and Grant Cooper, M.D., host of the radio show Back Pain Radio, had to say as they discussed the merits and risks of this traditional surgical procedure for reducing certain kinds of back pain.

Transcript of Back Pain Radio show on lumbar fusion surgery

Below is the transcript summary from the lumbar fusion surgery Back Pain Radio show on March 21, 2005.

Dr. Cooper: Lumbar fusion surgery has been around for a long time to treat back pain and spinal instability. The different ways of performing a fusion have been evolving and they continue to evolve. That in part has resulted in a lot of confusion surrounding lumbar fusion surgery. What is lumbar fusion surgery?

Dr. Ullrich: Very simply, it is an attempt to get two vertebral segments to grow together and turn it into one segment. The whole thought process is that if you have a painful motion segment in the spine, when you stop the motion, the pain should go away.

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Dr. Cooper: Do most people with low back pain ultimately require lumbar fusion surgery?

Dr. Ullrich: No, actually very few of them will. Lumbar spinal fusion surgery only works for specific indications and only can work if we can identify what the specific pain generator for the patient is. Probably 80-90% of the time, the pain generator can’t be identified.

Dr. Cooper: What are the most common indications for lumbar fusion surgery?

Dr. Ullrich: Currently, most people who have fusion either have back pain from severe degenerative disc disease or a slipped vertebral body (also known as spondylolisthesis). Both of those are fairly common conditions.

Dr. Cooper: Before diagnosing degenerative disc disease or pain that is arising from a painful disc that requires a lumbar fusion, does a provocative discogram need to be performed? Put another way, if I’ve been to my doctor, and I’ve tried physical therapy, over-the-counter pain medicines and other conservative treatments, and I’ve gotten an x-ray, and an MRI or CT scan, and my doctor tells me that I should get a lumbar fusion surgery for disc disease, should I be concerned that I haven’t had a provocative discography and that maybe the diagnosis is still uncertain?

Dr. Ullrich: There’s a lot of opinion on discograms and it’s still a controversial study. There are definitely surgeons who will not do a fusion without a discogram, and there are surgeons who will rarely if ever use them. Personally, I fall into the second camp and think you can get most everything you need off of an MRI scan to determine if it is a painful disc. Sometimes we will still use a discogram, but not every time.

Dr. Cooper: There are other treatments for disc disease, besides fusion surgery, including IDET which is an invasive but non-surgical procedure where a catheter is inserted into the annulus of the disc and then heated. Do you recommend that patients try IDET in particular or other non-surgical but still invasive modalities before fusion surgery, and if so, for which patients?

Dr. Ullrich: This is also controversial. We did try a few IDETs on some select patients and did not have a lot of success. At the meetings that I’ve been to, for the doctors who have done a lot of IDETs, it seems to work fairly well in about one-third of the patients and they will get good pain relief. But what we’re seeing now is a delayed effect where 2-3 years later, they will need the fusion. So it seems to be rather than a definitive procedure, at best more of a temporary effect. It might still be appropriate for some patients.

Dr. Cooper: For people who do have a fusion surgery, what percentage of them have complete relief after their surgery, what percentage have partial relief, what percentage have no change, and what percentage if any might actually get worse?

Dr. Ullrich: We just reviewed our own series of patients. For just those with level L5-S1 degenerative disc disease in young adults (average age was 42), of our 123 patients, 90% of them got substantially better and 75% had almost no pain. So, the spine fusion procedure was very reliable. But that’s at the L5-S1 level in young adults, and that’s what we try to limit our fusions to. We do some at the L4-L5 segment, and at L4-L5, L5-S1 levels, but that’s only about 20% of our fusions, while about 80% of the spine fusion surgeries we do are just at the L5-S1 level. For L5-S1, spinal fusion is a very reliable procedure.

Interestingly, the patients we reviewed had their surgeries spread out over the past 8 years and we haven’t had any of the patients with breakdown at the next level of the spine, which is another thing everybody worries about. This is called adjacent segment disease, and we just haven’t seen that yet as a problem and I’m not sure fusion accelerates it any more than what the normal aging process would. It is something that is sort of unclear right now.

Dr. Cooper: Do you do a lot of fusions in the older population?

Dr. Ullrich: In the older population, the disease entity will be totally different. In the younger patients, it’s either that their discs are breaking down (called degenerative disc disease) or their discs break down because of an isthmic spondylolisthesis, which is a small fracture in the back that leads to a slipped vertebral body. In the elderly, they have problems with slipped vertebral bodies because of arthritis in their facet joints and that almost always happens at the L4-L5 level, so it’s a totally separate entity. But there the fusion will work very well too.

Dr. Cooper: Do you have a similar set of relief data for your elderly patients?

Dr. Ullrich: In the past, we reviewed 60 patients who had fusions and found that about 95% of them had good functional relief. Now, we don’t expect the elderly population to be pain free because they still will have arthritis in other levels. They might still have a back ache, but they will be able to walk. The typical story here would be that they can’t walk more than 75 or 100 feet before they have to sit down, but after surgery they can walk a lot farther and without having pain down into their legs. That’s what we would consider a success in that disease entity.

Dr. Cooper: Are there contra-indications to lumbar fusion surgery?

Dr. Ullrich: The major contra-indication is if you can’t identify what the pain generator is. I think that is the major reason that lumbar fusions have gotten such a bad name. They have been done fairly indiscriminately. Early on in the 1950s when we had no way of identifying what was painful and what was not, it was routine just to fuse the bottom two levels and hope the pain would go away. Now we have MRI scans, but it took us awhile to really identify what the findings were on the scan to determine whether or not someone needed a fusion. Personally, the reason I don’t use discograms is that I think it leads people to do more levels than need to be done. The more levels you do the more chance you can have of either adjacent segment breakdown or failed fusion.

Dr. Cooper: There’s a doctor in California who feels that discography should be used more to rule out discs than to rule them in for just that reason.

Dr. Ullrich: I would agree. I would say I probably use a discogram more often when I don’t want to do a fusion.

Dr. Cooper: What are the risks of having a lumbar fusion surgery?

Dr. Ullrich: A major risk is that you might actually not get a solid fusion, which is called pseudoarthrosis (or nonunion) or when the joint is still there and still moving. With modern instrumentation systems and modern techniques, pseudoarthrosis rates are going down quite a bit. But there are still failures more often than not because we haven’t identified the pain generator even though we are getting better fusions.

Dr. Cooper: A lot of procedures get a bad rap because they are done on a patient population that the procedures weren’t designed for in the first place.

Dr. Ullrich: Yes. If the joint doesn’t hurt the patient, then removing the joint motion and fusing it isn’t going to help them. I think we’ve been overly aggressive too. The back is intended to move. There’s a term that’s been coined “fusion disease”, where basically too many levels are fused and now the back no longer moves. If we stick to, especially in younger patients, fusing L5-S1, it isn’t a motion segment anyway, it’s deep in the pelvis, and it’s got big ligaments - so when we fuse it, we don’t change the mechanics of the back very much. If we cross the L4-L5 level, that’s where we change the mechanics quite a bit.

Dr. Cooper: After lumbar fusion surgery, are patients required to limit their activity in any way? If so, what are they allowed to do and for how long do they have to maintain these restrictions? Does it depend on the level of the surgery.

Dr. Ullrich: In general, most people feel it takes about three months for the fusion to take and at least to set, so the biology of the bone graft is that the more still we keep the fused segment of the spine for the three months after the fusion surgery the better it sets. After three months, I encourage my patients to use their spine, because bone is live tissue and if you stress it, the bone will get bigger and stronger with time. So, the limitation is just for about three months. For one-level fusions, patients won’t have any activity restrictions from then on. For two-level fusions, we might restrict them vocationally from doing heavy labor. But once the bone fuses, patients are allowed to use them. When we say we don’t want them to use it a lot for those three months, we mean we don’t want them to do repetitive bending, lifting or twisting, and no sporting activities or labor. But they can bend over to tie their shoes and certainly can walk, and the more walking the better which helps the fusion process.

Dr. Cooper: But after three months, whether it was a two-level fusion or not, they can go back and play tennis, golf, and most of their normal daily activities, just maybe not heavy lifting.

Dr. Ullrich: And the vocational restrictions, where they would be forced to actually use their backs. For recreational activities, they can certainly do anything to tolerance. Basically after the first three months, they would have to get back into everything gradually, in a step-by-step fashion.

Dr. Cooper: How long does the lumbar fusion procedure itself take?

Dr. Ullrich: That is widely variable. It depends on how the procedure is done and also the experience of the surgeon. An anterior lumbar fusion procedure right now in our hands takes about ½ hour and is mostly done on an outpatient basis, and that is what we will normally do for an L5-S1 for degenerative disc disease.

Dr. Cooper: In terms of approach, there is anterior lumbar fusion (which means cut from the front) and posterior lumbar fusion (which means cut from the back). Can you tell me if one approach is better than the other, what the risks are of both, and when you might elect to do one or the other?

Dr. Ullrich: It largely depends on the surgeon’s training. In general, orthopedic surgeons are more comfortable going from the front, and the surgeries are usually done in conjunction with a vascular surgeon. For neurosurgeons, a lot of their training is done more in posterior fusion techniques. By going through the front, it is a very anatomic approach to the disc space. There are biomechanical advantages: we can distract the disc space and open it up quite a bit so if there is any stenosis over the nerve root as it exits that level we can decompress it indirectly. Also we can get a nice fusion bed and take out most all of the disc, and we can get a much nicer graft and interbody fixation device from the front, which is why we can often just do it from the front alone.

What we can’t do if we go from the front is do a posterior decompression, so if that also needs to be done we will need to go front and back, whereas surgeons who do everything from the back can also decompress at the same time. The fusion process from the posterior approach is more destructive for the muscles. From the front we don’t have to cut any muscles at all, as we go in between them. From the back, we have to elevate the muscles and it takes a long time for them to heal.

Dr. Cooper: When will the patient know if the lumbar fusion surgery was a success? How long after the surgery should the patient expect to feel better?

Dr. Ullrich: That has been changing, as our instrumentation systems have gotten more stable, people have been getting better quicker. Basically, the more stability we give them right off the bat the better they will feel right away. When we didn’t have very reliable instrumentation systems, patients would take a long time to feel better. As a matter of fact, what has changed the most since the 1970s is how quickly people are getting better. It used to take at least one year in the 1970s. Now many people within two weeks are feeling quite a bit better.

Dr. Cooper: That’s a major improvement.

Dr. Ullrich: It is, but still we tell patients that even if they haven’t had improvement up to 12 weeks, as long as they have seen some improvement around 12 weeks they should expect to see continued improvement. Definitely when we have looked at our data, patients are better at 12 months than at 3 months after a fusion surgery.

Dr. Cooper: If symptoms do improve, for how long do the improvements typically last?

Dr. Ullrich: Again, it depends for what reason the surgery was done. For a single level at the L5/S1 level, I would expect improvements to last at least until the patient becomes elderly. When they become elderly, then they could end up having problems at the L4/5 level like any other elderly person. In the elderly, interestingly, we have more people that break down at the level above, probably about 5% do, and that’s as much to do with the fact that they still have ongoing arthritis at unfused levels. It really is a different disease entity than in the young. In the young, often times the damaged disc is due to an injury and the rest of their spine is normal, so the benefits should last a long time. In the elderly, because it is arthritic, it doesn’t last quite as long but there is less stress on the back as we get older.

Dr. Cooper: What is minimally invasive lumbar fusion surgery?

Dr. Ullrich: That is more of a marketing term than an actual surgery. There are all sorts of different ways people could consider a surgery to be “minimally invasive”. When we used to try to do minimally invasive interbody fusions with a scope, most people gave it up because it was much less invasive to do it through a mini open procedure. So, it is a relative term. The goal of the surgeon using that term is to try to minimize the amount of soft tissue trauma by doing at least a portion of the procedure through a scope or through a tissue expanding retractor. There is a whole host of different ways right now of doing lumbar fusion surgery in a minimally invasive type of approach.

Dr. Cooper: Of course it’s great to try to be minimally invasive, but if you don’t get the segments fused then you haven’t really done the work you needed to do.

Dr. Ullrich: Excellent point. There is some danger to using that term as a marketing tool. If you are not creating the biological situation where the bone will grow together, it doesn’t matter how minimally invasive it was - it’s not going to help. A lot of the minimally invasive approaches do actually limit your visualization and make it tougher to actually complete the process of what you want to get done.


Additional disclaimer: Spine-health.com does not offer medical advice or treatment. This information does not replace the physician-patient relationship, and the information is not medical advice or treatment. It should only be considered as a physician's opinion. Patients should always seek the advice of a trained health professional for back pain or any health condition. Please note that the contents of this section have not been peer reviewed by Spine-health.com’s Medical Advisory Board.

Further Reading: Lumbar Spinal Fusion Surgery