If you do reach the stage where you are discussing surgery, the most likely is an arthroscopy, keyhole surgery into the knee. The surgeons can do all kinds of things that way trim torn cartilage, smooth weight-bearing surfaces and even repair torn cartilage. Then there are other forms of reconstructive surgery bigger operations that can reconstruct the ligaments or even replace the whole knee. But these major operations arent without risk and they may not always succeed sometimes its much better to go without them, so its important to get as much advice as you can on your particular case. Knee replacements are much more successful than they used to be but theyre still only really for people who have tried everything else and simply arent mobile enough.