Wow!! This reminds me of my sister in law's friend in Washington. Their little girl had a similar situation, and my SIL is trying to raise money for them because the insurance does not cover the rotation plasty. Basically, they remove the affected knee joint and use the foot, turned backward and grafted on, as the new knee joint. (The heel is like the kneecap) This gives them use of the knee like never before! Just amazing what they can do....
I pray you raise a lot of money! If I had any, I'd give you some. :/