How long does it take to grow back cartilage on your knee cap if you take glucosamine and chrondroitin? I don't have much cartilage on my knee cap and I wouldn't mind avoiding another surgery, had two hip ones this summer.

An extremely long time even if it does happen. This stuff works best if you're just starting to lose cartilage, not when most is already gone so you may be looking at surgery on knees to save your hip surgery, as bad knees will take out ankles and hips in no time, but there is a series of three shots that are supposed to be the last resort before knee replacement and are better than corizone injections, but I've forgotten the name, sorry. But I would do whatever it took to save those new hips now. Good luck.