Issues to Consider Before Having Artificial Disc Surgery

[Justin]

Issues to consider before having artificial disc surgery
http://spine-health.com/topics/surg/...harite003.html

As with any new surgical procedure, there are a number of factors that should be considered prior to undergoing an artificial disc surgery. A number of factors that may be helpful for patients to consider when considering whether or not to have artificial disc replacement surgery are outlined below.


1. Surgeon training. Historically, the extent of training for spine surgeons to use a new technology has varied greatly. Some surgeons have pursued a level of training similar to that employed for the device�s FDA trial, but unfortunately, this has not always been the case. There are currently no well defined, accepted standards for the training of surgeons wanting to employ the use of new technology.

The manufacturer of the Charit� artificial disc, DePuy Spine, has stated that prior to doing any surgery with the Charit� disc surgeons must undergo extensive training sponsored by DePuy Spine. This mandatory training includes a combination of participating in artificial disc surgery procedures with other trained surgeons, consultation and visitation with spine surgeons, and lectures and educational materials.

In addition, the Spinal Arthroplasty Society has set a goal of establishing standardized training programs for physicians prior to their using any new artificial disc replacement technology. It is intended that the training be similar to that required for participation in the FDA clinical trials. While such training is expensive and time consuming for both the surgeons and faculty, there are many important benefits for patients, surgeons, hospitals, and manufacturers or the artificial disc.


2. Surgeon skills. As with any type of spine surgery, the skill and experience of the surgeon performing the surgery is an important consideration. Unfortunately, this is usually difficult for patients to assess and there is no central source that reports on a surgeon�s outcomes. In general, it is a good idea to research a spine surgeon through some combination or asking a referring physician what their opinion is and asking other patients who have had the same procedure done with that surgeon.

As a general rule in surgery, a surgeon�s skills evolve and sharpen with more experience with a particular procedure. With the artificial disc procedure there is definitely a steep learning curve that includes learning how to use new instruments to implant the disc and to distract (open up) the disc space, and learning how to properly fit and place the disc in patients with different anatomical characteristics (e.g. a collapsed disc space, minor slippage of the vertebra that requires realignment, etc.). Many surgeons will also need to learn how to do back surgery by approaching the spine from the front (through the abdomen) instead of through the back. Many surgeons believe that having extensive experience with doing spine surgeries from the front (e.g. anterior lumbar interbody fusion surgery) is an important foundation for learning the artificial disc procedure. However, this is a debatable point as it has not been studied or proven.


3. Patient selection. As with a spine fusion surgery, making sure that the individual patient is a good candidate for the procedure is essential to success. Here are a just couple of examples of how inappropriate patient selection can have serious consequences:


If a patient receives an artificial disc, but the disc that was replaced was not actually the cause of the patient�s pain, then the patient will have undergone an extensive, invasive and costly procedure but still have the same level of pain. This may seem like an incredibly obvious point, but with back pain it is often difficult to pinpoint the precise cause of a patient�s pain. Accurate and careful diagnosis of the patient�s pain generator is crucial and cannot be overemphasized.


If the patient does have a painful disc, but other factors (such as significant degenerative changes in the facet joint) are present, then the patient may have to undergo a revision surgery after the initial surgery to either correct the placement of the disc or fuse the spine�a situation that is definitely best avoided by correctly assessing all the risk factors prior to the first surgery.


4. Reimbursement and expense. Typically, the total cost for an artificial disc replacement surgery ranges from about $35,000 to $45,000. Many insurance companies still consider the artificial disc an experimental or unproven procedure and therefore may not provide full coverage or any coverage at all. Currently, under Medicare and Medicaid only partial reimbursement is provided. While the reimbursement environment may improve over time, it is uncertain when and by how much it will improve.


5. Potential long term issues. As a general precaution, it should be noted that in the U.S. this is still a new technology and, as such, long term effects are not known. Any new medical technology carries with it a certain level of unknown risks. As an example, it is thought that most patients receiving a lumbar artificial disc will be about 30 to 40 years old at the time of the disc replacement, which means that to avoid the need for revision surgery, the disc prosthesis must last 40 to 50 years for most patients. At present, there are no indications that the disc will not last, but this is one example of an unknown risk that has yet to stand the test of time.


By: Stephen Hochschuler, MD and Paul McAfee, MD
November 16, 2004


Spine-health.com > Topics > Surgery > All about the Charit� artificial disc

[Janie]

Before ADR surgery
Just thought I'd add that my Doctor advised Bone Density Scans as the plates need a fairly strong structure
And it is certainly worth consulting with your doctor

Janie

[Jo]

Re: Number 5, Dr Fenk-Mayer answered this question for me a few weeks ago. She said that ADR's are likely to need replacing when used in younger patients as they are unlikely to last 40-50 years. The Charites implanted in the 80's are suffering from asceptic loosening (as do hip replacements after 10-15 years), and that there is nothing to suggest that this won't happen with any other device with a polyethylene core in use currently. She said this occurs due to the effects of polyethylene debris, and would therefore make revision surgery likely for someone who received an ADR in their 30's or 40's.

[Justin]

Jo,

Thanks for your reply.

When I asked Dr. Bertagnoli when I should to expect a revision surgery, he turned around with a suprise look on his face--he said, "There should be no need for revision as the arc motion in the spine is significantly less than knees and hips."

Hopefully when I graduate from medical school I will have made many friends with future surgeons that can take care of me down the road. Oh well, I have youth on my side in many respects.

Justin

[Harrison]

Folks, this is great discussion. I'd like to find a way to steer this into the main forums, and there's a number of ways to do this. In the future, I'll restrict comments on the "Article Library." In the meantime, this will be moved to Arthoplasty Central.

I hope this makes info easier to find for all...

[Jo]

All the surgeons I've asked in the UK have said that ADR's will probably not last a lifetime for younger patients. In fact when I spoke to one doc (who is pro the concept of ADR but says the technology isn't there yet), he corrected my "if" they need replacing to "when". He said that whilst the range of motion of a spinal segment is less than that of a hip or knee, the shearing forces are greater. He was previously an engineer.

Dr Fenk-Mayer basically agrees with all the surgeons I've spoken to in that she says the implants will probably need replacing, and she went on to say "In hip prostehsis loosening is known and not considered an obstacle to this most beneficial surgery � because loosening can be and is routinely addressed by replacement surgery. We`d expect the same in ADR.
Even irregular or complicated cases, where replacement of the ADR would not be feasible, not could always be revised into a fusion."

Which brings us to the discussion about the reality of fusion post ADR, which also carries many uncertainties, and in the instance of fusing posteriorly is in conflict with the fact that one is leaving in place a motion-giving device whilst trying to stop motion from the posterior structures.

[Janie]

Hey all
My Doctor said the same about Disc/ ADR movement
compared to hip and knee replacements as Justin's and sure hope they are right to late now anyway
My Dr made me very aware that core strength excercises were now a life long goal after ADR surgery especially stomach and back muscles which will support the surgery and also correct posture & bending
Best wishes
Janie

[bobb0]

Jo, where is this information that indicates 'asceptic loosening'. AS I recall this phenom was not alluded to in FDA approval meetings. If this indeed is factual it blows my mind that any doctor or any patient would participate in this surgery. If we knew the implants were loosening already we absolutely would not have gone with adr.
In the last year much has been made on the forums of the synovial fluids being the carrier of the wear debris. Since the disc is not a synovial joint the theory was the wear debris was not finding it's way behind the end plates and degrading the bone structure. Has this thinking changed??

bob

[Alastair]

Hello everybody,
the first let me say that in comparison to the European doctors, the UK doctors know very little indeed and certainly don't have any records of their own with regard to the life of ADR protheses.This is the one big problem the UK doctors have and they will not accept the European figures.

I think that one has got to look at what is going to get you out of pain, and keep you mobile, even if it's only for 30 or 40 years, at this moment in time that is the best option which is available.

Having so said there are no guarantees that ADR will initially work for everybody, every surgeon has his failures as well as his successes.

The lifetime of the current ADR is unknown, and those of us with these implanted are going to be the people who find out. I fail to understand about the comment about the Charitee loosening. These protheses have bone growing round them, so the metal plates certainly will not move. The current plastic discs have extremely high performance wear factors, so I think this is a completely different issue to those which were implanted in the 1980s.

In conversations with the European doctors and I do understand that in the early days of the 1980s there were all sorts of weird things going on as the new technology of ADR was taking place.

In the current days with the new materials, I feel quietly confident that ADRs will certainly outlive the patient.
Best wishes,
Alastair

[Jo]

Most of our doctors are more conservative and prefer to go on properly conducted clinical studies where medical companies and personalities have no influence. They prefer to go on facts rather than supposition. For example Dr Fenk-Mayer admits that no-one knows about the lifespan of ADR. It's a fact that ADR does not have a higher success rate than any other type of spinal surgery, and there are more unknowns about it.

As I said, the information about asceptic loosening came from Dr Fenk-Mayer. I'll quote the whole email conversation, word for word:

My Question: "On what are you basing your assumption that the implants will last 50+ years?" (I thought that I'd read that Dr B' and her had said that there was no issue with lifespan, hence my assumption that this was her belief)

Her Answer: "where did you get the 50+ figure?

Certainly noone can forsee the exact life span of a ADR � after all the first comparable models where implanted in the 1980ies (Charitee).

We can though make biomechanical considerations, and draw parallels:

o The material is known from hip prosthesis for more than 50 years, so this will not be the problem.

o From hip prosthesis we know, that the issue to consider is aseptic loosening of the metal surface from the bone with time. This time is directly related to polyethilen debris. In hips the median is about 10-15 years (and e.g. longer in elder patients, fewer in younger, because they just move around more).

o The range of movement of a disc prostehsis is max 10 degrees. The ROM of a hip prosthesis should be over 120 degree. So the expected polyethylene shear is much less in an ADR � so the expected life-span should be much longer than in hips.

The ADRS implanted in the 1980ies did not experience aseptic loosening in general until now.

The second and important parallel is possible treatment of loosening
In hip prostehsis loosening is known and not considered an obstacle to this most beneficial surgery � because loosening can be and is routinely addressed by replacement surgery. We`d expect the same in ADR.
Even irregular or complicated cases, where replacement of the ADR would not be feasible, not could always be revised into a fusion."

The question according to Dr F-M is not one of whether the materials will last, but one of what to do when the debris causes loosening.

It's my belief that it's not so easy to replace or fuse ADR's, as is being shown by the unlucky people who currently need a solution to failed ADR, and are not being quite so readily helped by the surgeons who said "oh we can fuse you if it fails".

Show me some patients who have had failed ADR and have had successful replacement or fusion and I'm happy to have my mind changed. You think I don't want ADR to be the answer?