Surgery Details Part 1: My Knee Story, and Meniscus Transplant

I'm a sucker for knowing as much as I can about different things that roll into my life. Sometimes that's a good thing (knowledge is power), and sometimes that's a bad thing (that time I researched the details of the surgery my oldest son needed to remove a benign tumor in his inner ear). 

I consider myself lucky that, as a medical person, I understand anatomy and physiology and know what and who to ask, and where to look for the best information.

So here's the rundown on what I've learned about this knee surgery I have coming up. This is as much for me as it is for anyone else. If anyone in the future is frantically looking for meniscal transplant surgery info like I was 2 months ago, and stumbles on this blog, this post will be a good resource for them. The other blogs I have perused regarding this topic were focused on recovery and return to activity. There was very little technical info. And I like the technical stuff! Once I understand it, the surgical plan, and pain expectations, and recovery process all make a lot more sense. 

So above is a picture of a healthy knee, as if you were looking at someone facing you and they had no skin on their right leg.  My injury is on the medial meniscus (which actually doesn't exist in me anymore), the articular cartilage on that same (medial) side, as well as the ACL which is one of the pink bands behind the patella. Mine is my left knee though, which doesn't matter at all, except for accuracy purposes. 

So I'll start with the meniscus transplant. 

Above is a picture of my knee taken during my diagnostic arthroscopic surgery in August. In the space where the surgeon's metal instrument is, there is supposed to be a smoothe pale structure (medial meniscus) that cushions the blow every time I take a step...but the medial meniscus in me is missing. The main reason for my knee pain!

This (above) is what the knee would look like if you were looking down without the big thigh bone on top. The purple structures are the two meniscus'. 

The problem with the meniscus is that there is a very poor blood supply to both...so injury means it usually stays injured. It is very hard for a meniscus to heal and be repaired. The other problem is that the meniscus is annoyingly necessary if you want to have a healthy active lifestyle. Especially the medial part. It is thought that with just regular walking, the knee joint takes an impact of 6x the person's body weight...

wait, it gets better

...and 70% of that force is absorbed by the medial meniscus alone. 

So yeah, it's important. 

I injured my left leg medial meniscus in college as an 18 year old, and awesomely enough don't remember how I injured it. I woke up after a night of too much fun and couldn't bear weight on my left leg. Yay for college! So I went home and had surgery where the doc removed the damaged part of the meniscus. 3 weeks later, it was like nothing ever happened. 

Fast forward 13 years, to 7 years ago, to me being a woman in her early 30's. I was resting a stress fracture in my foot and was cleared for activities, just not running. So I took up martial arts!  A few months into it, I had an acute tear of my ACL in the left knee when I planted my leg to throw a kick. I had surgery, rehabbed the hell out of it, and became a "real" runner, and felt invincible. 

What I didn't know about the ACL repair is that 

a) the doc "trimmed away" more of my medial meniscus (who needs it right?!) and 

b) attached the ACL graft in a place that is no longer recommended because...get this...it can wear away at the articular cartilage if you are deficient in the medial meniscus (my articular cartilage is one of the injuries also being fixed in this surgery).

So, now we speed up to just about 18 months ago, I was running and having the time of my life, getting faster and making running friends, and I was out running a normal any day run and one step felt fine and the next step felt like the most excruciating pain ever. That, I'm pretty sure, was the final bits of my medial meniscus saying goodbye and falling away into my knee space. 

R.I.P. Meniscus. You served me well-ish for 38 years

So the only way to preserve the bones that make up the top and bottom portions of my knee joint, is to transplant a cadaver meniscus.

This surgery was first done in 1979, but didn't become more common until 2005 and later. There is a very specific population that is suitable for this surgery:

Under 50

Not overweight

Non-smoker

*Intact ACL

Only one knee compartment affected

Active and able to do the rehab

*No cartilage defects

No mal-alignment in the legs bones 

The * mean that I don't actually qualify on those points but that's where the other 2 parts of the surgery come in.

First, Dr. Z took all kinds of measurements of exactly the size meniscus I need and sent it to the tissue bank they work with. The people there will look for a cadaver medial meniscus that fits the bill, or knee. The donor needs to have been young, and it needs to be almost exactly the right size. 

He will then take the meniscus on the day of surgery, and sew it into place!

 

So the surgery is delicate and takes a long time. Added to it the other 2 parts of the surgery I need (there will be a "part 2" post that will talk about those), it means this surgery will be complicated. 

The 5 year success rate is 85%, but success rates are hard to calculate when there's so many factors to consider...

Did the person have other repairs along with the transplant?

Did the person return to vigorous activity after, or modify their lifestyle?

Etc...

At the 2 year mark, almost half need some scar tissue debridement. Graft failure is considered anything lasting less than 5 years. 

Kind of crazy going into this knowing this big surgery is a temporary fix. 

If you've read up until this point, I commend you. I'm not sure that anyone else wants to know all of this, but again, this is as much for me to document what I know as it is for anyone else.