Artificial Cervical Disc Replacement - Justin Paquette, MD

Dr. Sechrest: Hello, I'm Dr. Randale Sechrest, your host for eOrthopod.TV. Today I have with me as my guest, Dr. Justin Paquette. Dr. Paquette is a neurosurgeon who practices complex spine surgery in Los Angeles, California. Dr. Paquette did his medical training at Albany Medical College. He then went on to complete residency in neurosurgery at the Harvard Tuss Combined Program in Boston, Massachusetts. From there he completed a fellowship in complex spine surgery in Los Angeles at Cedar-Sinai. Good afternoon, Justin.

Dr. Justin Paquette: Good afternoon.

Dr. Sechrest: Dr. Paquette, today what I'd like to discuss is a relatively new procedure called the artificial disc replacement, and we're specifically talking about artificial disc replacement in the neck. Tell us a little bit about this. I mean, this is a new procedure that seems to be very popular these days.

Dr. Justin Paquette: Sure. So essentially the purpose of an artificial disc is to preserve the normal motion of the spine. In the old days, we would just fuse a level, and we do this today as well, where we fuse a level and take the motion out of it so as to prevent any pressure on the nerve or the spinal cord. The artificial disc, however, instead of fusing two vertebrae together actually links in-between where the disc was, but allows bending, twisting, flexing, extending in all the normal directions. The main reason why this was developed was based upon a theory called adjacent segment degeneration. What this theory states is that if you take one segment of the spine and you fuse it, you've basically taken one motion segment out of the spine. So if you had, say, seven discs or six discs in the spine all doing certain amounts of movement, and you took one disc and stopped it from moving, now the other discs have to pick up the slack, and now they have a little more extra motion, extra stress, and they may wear out faster than they would have normally. So the reasoning behind developing the disc was that if we can preserve the motion perhaps we can prevent that adjacent segment degeneration, prevent the worsening stress in the other discs, and perhaps prolong the life of the neck.

Dr. Sechrest: Okay. So, if I understand you correctly, the artificial disc is really a new option, so to speak, for situations where otherwise you would have done an anterior cervical discectomy and fusion.

Dr. Justin Paquette: That's correct.

Dr. Sechrest: When you do an artificial disc, other than the advantage of retaining motion, do you get better pain relief, do you get a better result than you would get with your typical anterior cervical discectomy and fusion?

Dr. Justin Paquette: It's interesting. The data is just basically coming out right now from the FDA studies. It's showing at least equivalency, and in some times, superiority to standard fusion procedures. One of the reasons may be is that in fusions surgeries we can't use any kind of anti-inflammatories after surgery, because anti-inflammatories are anti-fusion. But in the artificial disc category we can use as much of that as we want to because we're not going for a fusion. So that may help to actually control the patient's postoperative pain.

Dr. Sechrest: So what does that mean? Does that mean that if I'm a patient and I'm looking at the option between having an artificial disc or having the older anterior cervical discectomy and fusion, that I'm going to have a better postoperative course? Or a year down the road am I better?

Dr. Justin Paquette: Like about a year out they're probably pretty similar, but there's a much faster recovery with those that have the artificial discs.

Dr. Sechrest: So it's a faster recovery. How about surgery-wise, is it a harder surgery? Is it easier for you, as a technician, when you look at the difference between doing anterior cervical discectomy and fusion and an artificial disc, what's the difference?

Dr. Justin Paquette: In essence, there very similar surgeries. They're both done with a small incision in the side, coming from the front, taking the whole disc and putting an implant between the two bones. However, the artificial disc has to be done much more precisely. A fusion, you'll always get a block of bone in there, in the right area, and if the plate that goes on is locked in the right area, the bone's going to fuse and the patient will do well. But the positioning of the artificial disc is critical. If you think about it, the biomechanical properties are absolutely dependent upon where each bone is located and they all have to move in all different directions together. If it's off balance then you'll no longer have normal motion and that's actually going to hurt you more than help you, and so the disc has been designed based upon the normal biomechanical properties of the spine to be placed in exactly the right spot. So what we do is spend much more time with x-rays and with the microscope to make sure that when we place it, it's dead center inside the disc space.

Dr. Sechrest: So, am I correct in assuming that the operation takes a little longer than it would take you to do an anterior cervical discectomy and fusion.

Dr. Justin Paquette: I would say it probably takes a little bit longer. Not much.

Dr. Sechrest: Okay. How about recovery-wise? You mentioned that people can be treated more aggressively with anti-inflammatories and that sort of thing. Do you that patients are able to return to work faster? Do you release them faster when they have an artificial disc? Or is the same as the anterior cervical discectomy and fusion?

Dr. Justin Paquette: Sure. My personal experience has been that it's pretty similar. Patients may return to work a little bit faster, and again this is probably related to the anti-inflammatory usage, but in general it's pretty close. People leave the hospital either the same day or the next morning, driving within a week, working within a couple of weeks, physical therapy all at 6 weeks. If you look at the FDA studies, there's a trend towards artificial discs going back to work earlier. But, in my practice, so far it seems relatively similar, but they're feeling better during the recovery process.

Dr. Sechrest: Okay. Any other substantial differences between the patients that you would recommend an artificial disc to someone who you would advise to have the old tried and true method of the anterior cervical discectomy and fusion. How do you make the decision?

Dr. Justin Paquette: Well, there are certain definite contraindications to certain individuals getting the artificial discs. Those would be anybody with fractures or dislocations, anybody with spinal tumors certainly not; osteoporosis is a contraindication, women over a certain age are going to be a contraindication also because of bone quality. If the joints in the back of the neck are completely gone, remember the joints and the discs are very closely connected at the same level. If the joints are totally gone and the disc is totally gone, there is no point in trying to salvage that level. They're still going to have lots of pain. If it's gone beyond moderate degrees of degeneration a patient should probably go ahead with the fusion.

Dr. Sechrest: So, if I understand that, then it would seem that the older you get, the less likely you are a candidate for an artificial disc.

Dr. Justin Paquette: That's right.

Dr. Sechrest: So the artificial disc tends to be a solution for the younger person in this day and age?

Dr. Justin Paquette: Yes.

Dr. Sechrest: Now how about levels, I'm assuming today, in 2008 when we're talking, this has been released to the open market. So this is no longer experimental, you can go to a neurosurgeon and have an artificial disc put in essentially anywhere in the country if they do it. It's not experimental. Insurances are paying for it. That's not a problem.

Dr. Justin Paquette: Correct.

Dr. Sechrest: What if I've got two bad discs? Can I get two artificial discs in this country? Or is it still just one?

Dr. Justin Paquette: No, the problem with that is that the FDA study was for single levels. There are some studies going on now that are two levels, but an FDA usage is for pure one level disc disease. Of course, the problem of which, is that most people have multiple discs that are bad in the neck. But, there are some places that will do it off label for two levels, but that is certainly not recommended. And the other issue we should just mention, insurances are not exactly making it easy to get these paid for either. Some of the initial lumbar artificial discs had quite significant complications and, based upon that, I think that a lot of the insurance companies are really making it difficult for patients to get qualified for artificial discs.

Dr. Sechrest: At this day and age, what about the patient who, as you had mentioned, may have had a cervical fusion, one level, 20 years ago, 10 years ago, and now because of the increased stress above and below that fusion, one of those segments is going bad. If you have a fusion at one segment, can I consider having an artificial disc in that segment above?

Dr. Justin Paquette: Yes, there's an absolute possibility. In fact, we've just done a couple of those recently.

Dr. Sechrest: So that's not a contraindication, any other surgery or anything like that?

Dr. Justin Paquette: Not a contraindication, no.

Dr. Sechrest: In terms of complications, obviously we're operating on someone's neck, the spinal cord is right there, there's lot's of big blood vessels, is there anything about the artificial disc that you worry about differently than you would your traditional anterior cervical discectomy and fusion? As a surgeon, what do you worry about as a complication when you do an artificial disc?

Dr. Justin Paquette: I think they're probably pretty similar, as far as complications which would have to do with blood vessels, have to do with the nerves that are there, etc. The amount of outside exposure is very similar. What's different is that everything has to match up perfectly. So, you have to spend more time drilling down the bone, inside and outside, to make sure that the disc, when it goes in there, is totally flush in all directions. We look at it on the microscope and then we also take many x-rays as well. So, certainly, there's more risk of hitting outside structures while you're doing that part of the procedure, but the only thing, in my hands, that is different than a normal one, is that you spend a little extra time making sure that everything just fits like a glove.

Dr. Sechrest: Now, this is a relatively new operation, at least in the United States. It's been done in Europe for some years. Can you give us, as a person who is on the leading edge of spine surgery, where's this all headed? What's next? Is the artificial disc sort of the epitome of state-of-the-art technology? Are we seeing new things on the horizon in the cervical spine that are going to make even the artificial discs seem old hat?

Dr. Justin Paquette: Artificial discs are definitely advanced. It's very exciting for us, especially much more so than the lumbar disc. I think the cervical disc makes more sense. There are less forces of gravity on it than there is the lumbar spine. I think that they will survive much better. First of all, we're still in the early generations as you point out. Some of the newer designs that will be available in the next year are going to be significantly better than the one we even have just now, and they'll allow us to do multiple levels at the same time without any difficulties. So that, alone, will be a significant advance. They are also working on ways of replacing the joints in the back. Facet joint replacements which, for a disease that doesn't affect the disc, will be a useful adjunct. But I think ultimately the most interesting thing is going to be the development of stem cells and the usage of stem cells in the rehabilitation and the re-growing of intervertebral discs. So, you take a disc that looks pretty bad, rather than putting any metal in there, just take a little needle, squirt it in there, and then over time have that regenerate a nice new disc for us.

Dr. Sechrest: Well that definitely seems like the Holy Grail. It seems like the fountain of youth.

Dr. Justin Paquette: Well, close enough.

Dr. Sechrest: Any parting comments to patients who may be trying to make that difficult decision, and they're talking to their surgeon, they may have had a second opinion trying to make that distinction between, "Should I have an artificial disc, a relatively new technology, or should I stick with the tried and true anterior cervical discectomy and fusion?" Any pearls of wisdom for those folks?

Dr. Justin Paquette: Sure. I think that both surgeries are very good surgeries. I think that, in the right hands, patients would do well with either of those things. The thing to keep in mind is that this is still a new surgery. The last thing that you want to do is try to push the bounds of indications for this artificial disc. We all need to be very careful to only put the disc in just the special patients who are going to do great with it. If you start to bend the character a little bit, and put it into older people, or people that shouldn't really need it, I think that's when we're going to start to notice complications and problems. So it's very important that when you have your discussions with your physician, realize what the realistic limitations of each device is.

Dr. Sechrest: Well, I think that will definitely help our battle with the insurance companies so that if they don't see us having a lot of complications with this new procedure, they're more likely to pay for it when it's indicated.

Dr. Justin Paquette: Absolutely right.

Dr. Sechrest: Okay, well thanks. Fascinating discussion. I appreciate you coming by.

Dr. Justin Paquette: Thanks.

Dr. Sechrest: Thanks for watching today. If you have questions about the topic that we discussed today, or any orthopaedic topic, be sure to visit eOrthopod.com. If you're an orthopaedic surgeon or healthcare provider interested in participating as a guest on eOrthopod TV, you'll also find instructions on how to apply to become a guest on eOrthopod TV. Thanks for watching.