Knee surgery??
I kinda know what your talking about because I've had my right hip replaced twice. First time was because I got hit by a car when I was 13. Many years later, because I didn't tell anyone about being hit ( I jumped up and ran off ) my hip was cracked and healed crooked. Wore the hip socket out and had to be replaced at 40. Later, as a truck driver, I was unloading a truck and tore the cup from my hip. Another hip now and I will never make that mistake again. Good luck on recovery. Pay attention to what the doctor says.