Artficial Cervical Disc Replacement - Nitin Bhatia, MD

Dr. Sechrest: Hello, I’m Dr. Randale Sechrest, your host for eOrthopod.TV. Today I have with me, Dr. Nitin Bhatia. Dr. Bhatia is a spine surgeon, who is the Chief of Spine Surgery, at the University of California Irvine. Dr. Bhatia did his undergraduate training at Stanford. He then went on to Baylor College of Medicine where he completed his M.D. degree. From there, he did orthopaedic surgery training at UCLA. From there, he finished a spine fellowship at the University of Miami. Today, he practices complex spine surgery at University of California Irvine. Good day, Dr. Bhatia.

Dr. Nitin Bhatia: Thank you for having me.

Dr. Sechrest: Dr. Bhatia, today what I would like to discuss is a relatively new procedure that is sort of taking the country by storm, and that’s the artificial disc replacement for the neck, for the cervical spine. I understand you do this procedure, and could you give us an idea of a little bit where this technology is today?

Dr. Nitin Bhatia: Sure, it really is a fairly new technology in the US, but the technology has been around for 20 years in Europe. Only recently has it transitioned to the United States however. Previously, it was used mainly in the lumbar spine, or low back, however we’re finding even better results when we use this technology in the neck.

Dr. Sechrest: Now, patients that are appropriate for artificial disc; what type of patient, what type of procedure is this replacing?

Dr. Nitin Bhatia: This is really a replacement for the anterior cervical fusion, and that’s a fusion we do through the front of the neck after we take out one of the discs, usually because the disc is herniated and is pushing on one of the nerves causing some sort of arm or hand pain.

Dr. Sechrest: So this is something that we’ve treated in a different way up to this point. Now, my understanding is that anterior cervical discectomy and fusion is an incredibly successful operation. Why change now and take a very successful operation and do something different?

Dr. Nitin Bhatia: You know, that’s one of the hardest things to come to grips with when we talk about the anterior cervical disc arthroplasty or disc replacement, is that the anterior cervical discectomy and fusion or ACDF. is really an outstanding surgery. The results are great and they’re very reliable with very fast return to life with minimal downtime. So people ask, and surgeons ask, why should we change something that is that good? Well, one of the things I think we have to do to continue improving our field, is try new techniques in a very cautious manner to make sure that they’re appropriate and that we get at least as good results as we have with our other procedure.

Dr. Sechrest: Now are there specific advantages to the anterior cervical disc that you don’t see with anterior cervical discectomy and fusion?

Dr. Nitin Bhatia: Most of the advantages are somewhat theoretical, at this point. One of the thoughts is that if you do a fusion in the neck, possibly you move some of the forces from that level that used to have a little motion in it, to the level above it and below it; and those levels may wear out a little sooner than they would otherwise. Now, while that sounds very logical, most of the studies we’ve seen haven’t clearly shown that yet. But, theoretically, the anterior cervical disc replacement, which allows a little motion to remain at that operated level, can prevent translating those forces to the levels above and below.

Dr. Sechrest: Well, I think we’ve all seen patients who have had maybe two levels of cervical discectomy and fusion, and all of the forces transferred to those other two segments, and they do get into trouble several years down the road. So that adjacent segment disease, it’s sometimes referred to, is definitely a real thing if the artificial disc can help that I think we’re probably wise to at least test that hypothesis more than anything else. Well, tell me what is the ideal patient today for an anterior cervical disc?

What does that patient look like?

Dr. Nitin Bhatia: In my mind, the ideal patient is someone who has a one level disc herniation with well-defined pain due to that disc herniation. So the #1 step is we have to make sure that the problem we’re treating is going to get rid of their pain. Usually, the patients are in their 30s or 40s sometimes up to the 50s; and possibly they have a little degeneration already at the levels above and below in their neck. So by doing the disc replacement, we can stop, or possibly slow down, some of that degeneration versus doing a fusion at that level.

Dr. Sechrest: So you’re really interested in looking at that younger person who you really say, “I really don’t want to do a cervical fusion on this person because they are going to have to live a long time with this fusion”. If I understand you correctly, what you’re saying is that an artificial disc in that younger person may postpone that development of that adjacent segment disease, and that’s what we’re going for.

Dr. Nitin Bhatia: Right. That’s the theoretical advantage of it. One of the advantages that we’ve seen through some of the studies that are now coming out in the US, is that it probably works, at least in what we call the midterm, within the first couple years, as well as the discectomy and fusion; and some studies even suggest it may get rid of neck pain a little better than fusion does. But most studies show that they’re essentially equivalent.

Dr. Sechrest: Now in this country, right now as I understand it, this is no longer experimental. You can actually go in and choose to have an artificial disc with your surgeon and that is available to patients in the United States.

Dr. Nitin Bhatia: Correct.

Dr. Sechrest: There are a couple of special situations and, I guess, patients are always asking this: What if you have a fusion in your neck already and you’re developing adjacent segment disease? Is that patient a candidate to have an artificial disc used in that other area instead of a second fusion?

Dr. Nitin Bhatia: A lot of people develop degeneration in their neck, whether or not they have a fusion. If a patient’s getting degeneration in their neck, adjacent to a fusion, and they’re having symptoms from it, then they may need surgery for it. In those patients, they may be candidates for the artificial cervical disc. That being said, some of the discs, and there are a few models out there, kind of like there are a few models of cars out there, some of the discs fit better for those patients than others because they’re a little smaller and so we can put them next to the area of the previous fusion a little more easily than some of the other discs.

Dr. Sechrest: So it’s not a contraindication. If you’ve got a fusion in your neck right now, it doesn’t mean you can’t have an artificial cervical disc in some other level.

Dr. Nitin Bhatia: Correct, and in fact some surgeons would probably say that that’s a great candidate for it, to stop that adjacent segment disease from moving more cephalad or caudad up or down once you do a fusion at the other level.

Dr. Sechrest: Now, I think you’ve probably answered this question, but there’s no advantage of going in and trying to remove a fusion, for example, and replace it with an artificial disc?

Dr. Nitin Bhatia: Correct.

Dr. Sechrest: Nobody’s doing that in this country?

Dr. Nitin Bhatia: There have been a few people who have talked about it, but I think it’s probably not appropriate for the vast majority of patients. I would never suggest it.

Dr. Sechrest: Okay. Is there any difference in this operation? When you go to do this operation rather than do the anterior cervical discectomy and fusion, what are the differences that the patient is going to see when he goes to have the operation?

Dr. Nitin Bhatia: Really, there’s not a lot of difference. The main difference is intraoperatively with the patient asleep. We do the procedure and set up the procedure the exact same way. We do the discectomy, which is the procedure where we take out that herniated disc and open up the space for the nerves, essentially identically. Only, instead of doing a fusion, where we put a piece of bone graft and a small plate and screws on the neck, we put the cervical disc in instead. After surgery, the rehab and the physical therapy are essentially identical as well.

Dr. Sechrest: So you get over an artificial cervical disc about the same amount of time. I guess, one difference is that you don’t have to wait for the fusion to get solid.

Dr. Nitin Bhatia: Exactly. You don’t have to wait for the fusion to get solid and some surgeons will put patients in a neck collar after a fusion to try to let them heal a little more quickly – sometimes upwards of a month or two. With the cervical disc there is no collar.

Dr. Sechrest: I think I understand with the fusion where you put the bone graft in, a piece of bone between the two vertebrae, and then you hold it in place with a plate and screws. What holds the artificial disc in place?

Dr. Nitin Bhatia: They each have a little different mechanism for holding them in place. Usually they have some sort of screw that goes into the bones, but some of them just fit into the place and have small teeth that bite into the bones and hold it in place as well.

Dr. Sechrest: And does the bone grow into that metal or anything?

Dr. Nitin Bhatia: It does. They designed the endplates and the pieces of metal so the bone will actually grow into it and capture the metal so it won’t go anywhere.

Dr. Sechrest: Okay. In terms of the anterior cervical disc, when do you release patients to do anything they want? When are they completely released from any type of restrictions at all?

Dr. Nitin Bhatia: I usually release them at about 6 weeks after surgery, and even the first 6 weeks they can do almost anything they want to do, except I don’t like them lifting heavy things during that first 6 week period just to let the muscles and everything else heal around the neck.

Dr. Sechrest: Is there any long-term risk of the artificial disc over a cervical fusion? Should I be concerned if I’m skiing or anything like that? Do you restrict people from anything like that?

Dr. Nitin Bhatia: We don’t. Theoretically, because it is a mobile device, if there was some horrible accident perhaps it could pop out of place, but in the FDA studies that were done looking at the cervical discs, there were actually a couple of patients who were in bad car accidents after they had the disc placed, and they had cars totaled, they were in the hospital, but their discs survived with no problems.

Dr. Sechrest: Now, are there any other complications to an artificial disc? Are they essentially the same as well, the cervical discectomy and fusion? Are there any specific risks if I’m going to try to choose between the two?

Dr. Nitin Bhatia: One of the theoretical risks of it is that it could wear out. Like any other mobile device, whether it’s on your car, in your house, or in your body, anything that moves can gradually wear out with time. So there have been a lot of studies done in the laboratories looking at how quickly these will wear out. They’ve done mechanical studies, moving them millions and millions of times, with very, very minimal wear, but because they haven’t been implanted in humans for 10 or 20 years, we’re not sure how long they will last.

Dr. Sechrest: That brings up an interesting point. In the other areas of the body, for the most part, artificial joints are a combination of metal and plastic. There is some metal on metal. What’s the artificial cervical disc made of? Is this a metal device or is it titanium, stainless steel, plastic? What is it?

Dr. Nitin Bhatia: It depends on the particular model you’re looking at, but most of them nowadays are essentially metal on metal, and these use various kinds of metal. Some use stainless, some use cobalt, and some use titanium. They all work essentially the same and there are different reasons to use the different metals.

Dr. Sechrest: Okay. Do you any advice to patients that are now looking at this difference, and maybe their surgeon has said, “Well, we can do an anterior cervical discectomy and fusion, tried and true operation. Or we can do this new artificial cervical disc.” What would you tell a patient?

Dr. Nitin Bhatia: I think they’re both very good options for people with one level disc herniations who need a surgery. Really, the discussion comes down to a good patient-physician relationship. The results are probably almost equal, but some of the long-term results and risks with cervical discs probably aren’t very well known. We don’t know how long they’re going to last, if they’ll last 20 years, 30 years, maybe forever? Or are they going to be revised and are there any other issues with them that we don’t know yet. That being said, so far they look very safe and are a very valid alternative to fusion for people who don’t want a fusion.

Dr. Sechrest: You mentioned that these have been done for years in other parts of the world, in Europe specifically. How long have they been used in Europe?

Dr. Nitin Bhatia: The cervical discs have been used for approximately 10 years now.

Dr. Sechrest: So we still don’t know if they last 20 years.

Dr. Nitin Bhatia: Right.

Dr. Sechrest: I’m assuming that the data is pretty good from the European experience.

Dr. Nitin Bhatia: The data is quite good from the European experience.

Dr. Sechrest: Okay, well great. This has been a great discussion about a relatively new technology. Where do you see this going? If you had a crystal ball, do you think we’re going to abandon the anterior cervical discectomy and fusion and move toward the artificial cervical disc taking that operation and displacing it? What do you think?

Dr. Nitin Bhatia: You know, I don’t. I still think the discectomy and fusion is going to be the gold standard because it works so well, and, one of the great things about the fusion is that once it’s healed, it’s healed forever. You never have to worry about that area again. Also, the fusion really works on all patients who have a disc herniation or other problems. The disc replacement, or the artificial cervical disc, works very well on patients who also have that disc herniation. But if people have a little abnormal motion in their neck, or arthritis in the back joints of their neck, called the facet joints that are in the back of the neck, they aren’t great candidates for the cervical disc. So people who are good candidates, I do think the cervical disc will probably not replace fusions, but take up a significant component. But there is still going to be a big percentage of patients who just aren’t great candidates for the cervical disc for a variety of these reasons, mainly their overall alignment of their neck and the stability at that level, and fusions will probably remain the gold standard.

Dr. Sechrest: Well, thanks, wonderful information. I think that’s good advice for anybody, and it sounds like we’re still very much in a position where, if you’re given the suggestion or recommendation that you have an anterior cervical discectomy and fusion, that’s probably a pretty good bit of advice.

Dr. Nitin Bhatia: Yeah, I think so.

Dr. Sechrest: Thanks a lot.

Dr. Nitin Bhatia: It’s my pleasure, thank you.

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.