AMIC cartilage surgery for the knee

[ItsmeJPaulC]

Hi all,


I am scheduled to undergo knee surgery in a few weeks to repair a substantial level of osteochondral (articular cartilage) damage in my knee. The cartilage in question is of the lateral femoral condyle and it involves a weight bearing part also.
This injury happened to me approximately 14 months ago playing a contact sport. I initially underwent an arthroscopic procedure to repair meniscal damage, however the surgeon upon one month review stated that he was concerned about the substantial level of cartilage damage he noticed when doing the scope.

1 year has passed, and despite my best efforts of working closely with a physio to rebuild muscle strength and maintain flexibility, I was still hampered by significant pain especially when turning (while playing sport), landing, jumping, kneeling, and also frequent locking, swelling and catching sensations too.

I decided to reattend my surgeon to seek further support and he has been adamant that It is one area in particular in relation to sport's injuries that tends to be quite difficult to repair and enable a return to pre-injury level.
That being said, he has booked me in for surgery in a few weeks, and will conduct an initial arthroscopic procedure an d depending on the damage will either progress to carrying out AMIC surgery or Oats. He has stated that more than likely it will be AMIC surgery (autologous-matrix induced chondrogenesis) as it is a relatively new surgical procedure, and has exhibited notable results in the larger lesions of cartilage.

AMIC surgery seems to comprise of the beneficial aspects of microfracture surgery, whilst correcting some of it's notable flaws, such as the ability of the process to regenerate long-lasting cartilage (Sorry for my laymans way of describing the various procedures, I just happen to know the basics).
The main difference however is that it involves a membrane coating applied on top of the damaged area which further stimulates the healing process.


Seeing as this surgery is a relatively new technique, the literature around it is extremely limited- even more so for athletes. I would be delighted to hear from anyone who has any knowledge on this procedure, or even microfracture in general.
Questions i'd love to learn more about are:

How big of a challenge are osteochondral lesions in terms of athletes returning to sport?
What are the success rates for AMIC surgery for athletes? (If you haven't heard about this procedure what's the success rate for microfracture?
Does the regenerative cartilage formed with this membrane coating last a long time? Or does it tend to break down after a few years?



Many thanks,
any information would be greatly appreciated

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[physiobob]

Hi ItsmeJPaulC and thanks for your interesting post. If you have any images of the damaged area from the scope OR get some from this followup one please do add them to your post as it would be nice to see the area and size of the lesion in relation to what the surgeon suggests. I think AMIC surgery has been around for about 20 years but is only now starting to gain a little more widespread awareness. It's amazing how long new developments take to get out there and you'd be astounded at how in some areas they are using techniques from 30 years ago simply because the newer approaches have not reached them yet.

Mostly your own body generates the mesenchymal stem cells (MSCs) from the underlying bone, which can help regenerate cartilage, and it is the addition of the membrane 'cover' that gets stitched in place over the top which helps to keep them in place while together they produce that 'super clot' which can then become a protective layer of hyaline-like (articular) cartilage. I personally do not have specific experience treating a client who has undergone this procedure however the literature does suggest that the best outcomes are in those with only one defect in their cartilage. Having said that it does suggest a return to sport being possible at around 6 months. The current evidence has shown some individuals doing well even 10 years after the procedure. Everyone responds differently to injury and repair initiatives and no one injury is in the same place with the same load. So until we have 10's of thousands having had the procedure and returning to sport we cannot confidently give any longterm outcomes. In practice for recovery I would suggest 12 months considering the body repair and regeneration mechanisms and we would not want someone to return too early and risk excessive loading before the repair was stable. I say this as bone loves to form in areas of high load. And we do not want unnecessary annoying osteophytes growing in the cartilage repair. So I would take a long term view on it all and workout a really good rehab plan over that time. This often gives athletes the time to work on other skills to all them to come back even stronger. Additionally if the joint-brain connection considers that it is not fully healed then the brain-muscle-function will not fire up as normal due to a protective mechanism which you have little control over. That can then lead to an increased risk of general physical injury when playing sport.

Osteochondral autograft transplantation (OAT), also know as (Mosaicplasty), uses a donor site so I would want to be sure that the instability of the knee has no impact on the potential load in that donor area. We don't want to fix one issue now only to have another later in the donor site. So laxity in the joint following meniscal damage/removal or ACL or collateral ligament strains would be a consideration. In my view and OATs procedure might be more applicable to a non-sporting individual or for those not playing sports that include rapid changes of direction such as football.

In general microfracture, being used as an intervention to stimulate healing, has been around for some time. It seems that the surgeons believe it is a useful approach and the newer techniques are really working on how to better contain the resultant tissue stimulators released following that intervention within a specific area to improve the outcome. The size of the lesion, and if there are one or more of them, appears to be strongly linked to the outcomes.

I hope this provides a little more information. I would consider AMIC surgery myself if I had a single, not to large osteochondral defect in the load bearing surface of my knee joint. The general studies on the rehabilitation protocols are still very much on how much and when and these are still mainly looking at chondrocyte implantation approaches. I suppose in some ways they will form a useful guide in the early phases of rehab e.g. how long to stay on crutches.

Do let us know how you get on ;-)

[ItsmeJPaulC]

Hi,

Many thanks for your reply, it was extremely informative and provided me with a greater level of input on the issue than I ever expected I would receive on an online forum!
I have attached a picture of the scope, it is probably not of the greatest quality but you can certainly see a considerable amount of osteochondral damage.
One important aspect is it seems to be only a singular defect in the cartilage, there isn't multiple defects in different areas. I will admit though, and it has been outlined by the surgeon that the one defect in question is quite large, to the point that he deemed microfracture to be an inadequate option. I'm happy about this however as microfracture seems to be flawed judging by the literature.
My physiotherapist did also note that OATS whereby a plug of cartilage is taken from one part of the knee and placed into the defect can lead to issues down the line such as donor site morbidity, and it does tend to be more effective for smaller lesions. I am hoping that my surgeon in this case will pursue with AMIC instead, as I would be quite concerned if I woke up after anesthetic to be told that I had OATS performed.

'I say this as bone loves to form in areas of high load. And we do not want unnecessary annoying osteophytes growing in the cartilage repair.'

Would it be possible that you could elaborate on the above? I understand that you're saying that I take a considerable amount of time out from football (high impact sports), and I use that time to rebuild my strength in quads, hamstrings glutes etc. But I just don't understand what you mean by the above sentence, any input would be appreciated

Finally, just one other quick question also as it's been playing on my mind the past number of months. I'd be an avid gym lover, and would have always used the gym to enhance my sporting performance, but I'm strongly considering ripping up my current programme and tailoring and future plans to account for this current defect (and the regenerative cartilage that will be there in a months time. More specifically, I feel loading up on squats mightn't seem to be the most intelligent thing to do if I want to continue to play sport and have a fully functioning knee down the line. Do you have any knowledge on this area as research seems to be limited? I still obviously want to incorporate strength training to rebuild leg muscle and to improve sporting performance so maybe just drop the weight? Or just cut out squats completely?

Many thanks for your help

[physiobob]

'I say this as bone loves to form in areas of high load. And we do not want unnecessary annoying osteophytes growing in the cartilage repair.'

By this I mean that when the surgeon disturbs the underlying tissue to stimulate the cartilage it is also probable that osteoblasts (bone forming cells) are released. I think there have been some advances in the drilling techniques of the subchondral bone to minimise this. We see this in facet joint surgeries in the spine. Osteophytes make bone and respond to load. So as we would want to minimise bone formation I would take a slightly more conservative approach to the load bearing rehab in order to minimise that.

In terms of squats I would cut them out completely for now. Too much load. Progress will being with restoring full range body weight squats. Perhaps think more yoga or more active things like kettle bell type lunch and squatting movements at some stage ahead of squats specifically. In some ways depending on where the lesion is can help our therapist to provide more insight into which movements will load the area vs. those which will not.

;-)

p.s. I did not see the attachment so perhaps that failed when uploading

[ItsmeJPaulC]

Screenshot (11).jpgApologies, it should be attached now. I understand it's very hard to judge off a picture but let me know if you see anything worth mentioning