First of all there are no stage 5. There is 1 to 4, 4 being the very worst. That's when the knee cap doesn't go back in the socket at all. My Zada had stage 3 in both knees and had them both operated on at the same time. If your boy has a stage 4, then he would be having a lot of difficutly getting around and most likely be walking with a leg held up or not bending at all. I would get a second opinion, but keep in mind, if he does have a stage 4, then he should be having surgery before it's too late. |