I had a martial arts injury in 2012 that left my knee freely rotating. The hospital said nothing was broke and gave me a used pair of crutches, said don't wrap it and go see an ortho [Indiana, USA if your curious] At the time I was in a bad living situation and could not go to a doctor. I had to wrap it, keep it straight and non load bearing as much as possible while taking care of 3 kids. After I could set weight on it again I did my own therapy...gentle stretches and practicing weight load, slowly easing it back to normal weight distribution....but its still not perfect. For one the leg feels shorter and the knee doesn't straighten entirely..it gets close.. and even now if have moderate to heavy strain the knee which gives inward a little. About a year ago I could finally feel confidant in walking a flight of stairs with out fear of the knee buckling as for many years it would buckle under stress like...walking down the road, getting in and out of the car, up or down stairs or playing dance dance revolution. Weight gain from various activities hasn't helped either in all honestly...

But as of about October on last year I am finally able to roundhouse, front kick and side kick lightly which I couldn't before. Very slow recovery if you do it by yourself and kills your chance at doing sports activities. Definitely see a doctor and if your not sure then get other opinions.