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9/6/2005 12:40:44 PM - Where are the bionics?

A few years ago I had surgery performed on my left knee. Decades of playing soccer on the hard, uneven fields of Texas had apparently taken their toll.

The doctor had told me that I had a "Grade 4" defect...as it was explained to me, there are only four grades, and the higher the number the worse the problem. In my case, I had worn the cartilage away entirely in one area...in others, the cartilage had been fractured so much that it looked like a bomb had exploded.

Given that cartilage does not regenerate, this was obviously a huge problem. It meant that I often had bone touching bone whereas normally the cartilage would act as a sort of shock absorber to minimize the stress upon impact. That was causing pain, swelling, and various other problems. Playing soccer became impossible and I had to curtail all sorts of other physical activities.

That doctor recommended a procedure known as "microfracture". I read about it and wasn't impressed. The basic operation would involve clearing out the loose cartilage fragments and smoothing out the remainder. The doctor would then drill into the bone and cause it to bleed. That blood would then harden and form a type of weaker, softer "fibrous cartilage."

The long-term success rate of this procedure varies depending on a variety of parameters, but it's rarely a good solution for someone with significant cartilage damage.

When my right knee began to develop problems, I began hunting for something more technically advanced than microfracture. My father mentioned that he had heard of a company called Genzyme that could regrow cartilage for reimplantation. After checking into it further, I became convinced that "autologous chondrocyte implantation" (ACI) was a much more viable long-term solution.

Most orthopaedic surgeons aren't yet able to perform this surgery, but I managed to find a surgeon in Austin that had a significant amount of experience with it.

An initial arthroscopic examination (wherein the doctor is able to use thin tools to minimize the intrusion to the affected area) is typically performed to ensure that the patient is a viable candidate for the procedure. The defects have to be of a certain size, be surrounded by good cartilage, and meet various other requirements. Assuming these criteria are met, the doctor would then extract a small sample of your own cartilage from a non-load-bearing area. That sample would then be sent to Genzyme where it would be cultured and grown into a fluid-like substance.

A subsequent (non-arthroscopic, so it's much more invasive) surgery then has the doctor making two incisions. The first and smaller one is (in my case) near the top of the shin bone. A section of the bone's periosteum is shaved away to serve as a cap. A larger incision is then made over the knee itself. In my case, the defect lay in the trochlear groove so the doctor needed to use a clamp to hold the kneecap away during the procedure so that he could get to the area with the problem.

Any damaged articular cartilage near the affected area is drilled away in order to leave a clear path to the bone. The hole is then capped with the section of extracted periosteum and sutured to the neighboring good cartilage. The suturing process is complex enough that special training is required before a surgeon is allowed to perform the procedure.

Typically, the periosteum cap is placed over the defect and sutures are then sewn every 2 millimeters along the circumference. The sutures are linked into the neighboring good cartilage (which is, again, one of the pre-requisites for this particular procedure.) I had a 2.5 centimeter defect - about an inch in diameter - and that therefore required roughly 70-80 sutures. A small area is left unsutured so that the fluid from Genzyme (which contains the cells that will grow into your replacement cartilage) will be able to be inserted. Biological glue is then placed over the sutures to provide an even tighter seal. Saline solution is inserted into the defect (via the small, unsutured area) to ensure that the seal is tight enough to keep the cells in place over the months they will take to harden. When the surgeon is satisfied that the area is properly sealed, the fluid from Genzyme is inserted, the last small area is sutured shut, and biological glue is then used to seal it as well.

In theory, the inserted fluid should harden into actual cartilage that is as tough and durable as regular cartilage. The periosteum cap serves to keep the fluid in place until it attaches to the neighboring cartilage and hardens. That process takes about a year and is one of the reasons why the doctors will tell you that you should not over-exert yourself during the 12-18 month rehabilitation phase. If you dislodge the cap before the fluid has had a chance to mature, you will significantly reduce the likelihood of a successful procedure.

I just completed the implantation process and have been connected to a passive motion machine for the last several days (meaning that it simply bends my knee without any physical effort on my part.) I'll post more on how this procedure seems to be going as I experience it.

For now, here are some pictures...


Here's the knee before the implantation procedure...it's always a bit swollen nowadays because of the aggravation caused by the hole in the cartilage.


Getting ready for the implantation...


Removing the bandages...


The whole knee area - and even the upper leg - is pretty swollen two and a half days after surgery...


A side shot to show off some more of the swelling...and the staples.



- TZ

Add Comment

9/6/2005 4:08:04 PM by Keenan Weaver

Hey Tony,

I really hope everything turns out okay. I send my best wishes.


=========
The Ultimate Crusader Fan

-Keenan Weaver



-Keenan Weaver

9/7/2005 6:40:32 PM by BP

Those pics have ensured that no matter how painful I will not ever undergo any knee surgery. Ow.


-BP

9/8/2005 11:05:57 PM by Sting

knee surgery has progressed quite a bit since i had my acl repaired a decade ago...it-s amazing that they can now extract, grow, and reimplant cartilage like that.

good luck.


-Sting

9/9/2005 9:03:12 AM by TZ

It-s now been a week since the cartilage was implanted. I made a follow-up visit to the doctor yesterday to have the 20 staples removed. (Eight staples had been used for the incision at the top of the shin bone and 12 more had been used for the incision on the actual knee.)

They also checked to see how far I could bend my knee. I could do about 75 degrees pretty easily, but by the time I hit 85 degrees the swelling made any further rotation extremely difficult.

They suggested extracting a bit of blood from the knee to reduce the swelling. Given how sensitive the area was I wasn-t ecstatic about having a needle roughly twice the diameter of that typically used to draw blood poked into it. Interestingly, they first sprayed the area with ethyl chloride. This is a technique that-s occasionally been used since the late 1990s to reduce the feeling associated with shots. The spray is very cold and drops the temperature of the skin which in turns numbs it and dulls the feeling. The area was sensitive enough that it was still pretty obvious that a (large) needle was being inserted, but all things considered it wasn-t bad.

After inserting the needle, it then had to be firmly shoved into the joint with one quick motion. The ethyl chloride does nothing to numb that pain (since only the surface area of the skin is affected) and it was significant. The first 20 cc container filled up almost instantly. The needle was left inserted and the container replaced with another which took 20 more cc-s in about 4-5 seconds. The last container only got about 5 cc-s of blood before they decided that most of the easier fluid had been removed.

They put some tape over the incisions after the staples were removed, but I-ll post a couple more pictures once that comes off.

Removing the 45 cc-s of blood did make the swelling look considerably less. Twenty-four laters later, it looks far better than it did.

-TZ

9/13/2005 10:42:37 AM by Ring Zero

looks painful. hope you have a speedy recovery.

-Ring Zero

10/20/2005 4:12:41 PM by Mike Roden

I would like to stay abreast of you-re progress.

I have been diagnosed with a significant defect in the lateral area of my left knee.

I am 51 years old and lead a very active life in the outdoors.

my email address is mroden@hiwaay.net

Good Luck and would apreciate any info!!!

Mike

-Mike Roden

1/19/2006 6:32:16 AM by TZ

I haven-t posted an update until now because any improvement in the condition of my knee has been extremely slow in coming.

I was limping for the first several months after the surgery, but now tend to do so only after walking around for quite a bit. I may have been being a bit overcautious in this regard - I didn-t want to force the knee to bear too much weight until it felt ready. I continue to do a variety of daily exercises to strengthen the right knee and leg...leg extensions while laying down, simple flexing at a variety of different angles, riding a stationary bike with a fairly small amount of tension, etc.. Significant exercise - even just walking a half mile or so - still causes some minor swelling just above the knee.

I clearly have a long way to go before the knee feels perfect (or anywhere close), but it-s interesting to note that I no longer feel the sharp, shooting pain that used to occur when I would put pressure on the knee while rising from a sitting position. (Prior to the surgery, I would favor my left knee when doing things like this to minimize the pain.) However, at least thus far, this is probably at least partially due to the fact that I-m not placing the same level of stress on the knee whenever possible.

So...after four and a half months it-s still far too early to tell how all of this will turn out, but thus far I-d say it looks like the operation has provided at least some minor benefit in regards to the weight-bearing capability of my right knee.

In another year or so I should be able to answer the real question...how is this going to affect my soccer game?

-TZ

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