That's a cool thing with your knee & the stem cells from your belly. So you ar your own spare parts depot :-)

That reminds me on a tooth surgery I had in the 90s. I had a dead tooth and my dentist said it has to go. I was sad and didn't want it to go. As he was a very smart dentist he suggested to operate on my wisdom tooth in that corner of my mouth which had not grown yet and asked me if I was willing to take a risk.

I said: "Sure, if the bad tooth has to go anyway and also the wisdom tooth for lack of enough space, go ahead!"

So then he did the magic surgery, He pulled out the dead tooth, then operated on the wisdom tooth still in the flesh and inserted it into the resulting gap. Before that, he made me a splint so that the transplanted tooth had something to keep it from falling out. I carried the splint for two weeks. It was a fifty-fifty chance that it was tightly integrated into the gums. It succeeded!

The most natural dental prosthesis you can imagine! It lasted for over twenty years. Only recently the tooth began to shake and had to leave. It was sad. Like losing an old friend!

All the dentists who had previously looked into my mouth shook their heads in astonishment at the "wrong tooth" or the tooth in the wrong place. It's always been a pleasure to impress ordinary dentists. Mine was a Swede and a magician, too. That was his hobby.

Sorry to put a short story long but I had to do it! Some of the medical treatments are just great. Others suck.