I'm tall and slim and recently have been having really bad pains in my right knee. I can't walk on it or even drive now. Went to get an x-ray and an MRI only to find out that my cartilage is almost completely gone. How the heck did this happen if I never did sports? My doctor says it has to do with my scoliosis, but it still doesn't make sense. I've always been a walker and jogger, but I never did hardcore sports or anything like that.