I've got two CTi2 knee braces, one for the good knee and one for the bad knee. The bad knee went through a total rebuild in 1994 following blowing it in a hare scrambles. They replace the ACL and sewed up my medial meniscus. I wear them both when riding my dirt bike. I also wear one on the bad knee only for soccer, mountain biking, Jet Skiing, snowboarding, racquetball. I quickly adapted to wearing them riding and can run, etc. with the one on my left knee for other sports without a problem. The blown knee took me out of action for 6 months, the CTi braces are an effort to prevent that from happening again. This is a good product in that they are specifically molded for your leg so they are a great fit. The CTi2 is one of the better braces specifically for ACL problems, certainly better than the Don Joy for instance. The adjustable braces are a little too loose fitting in my opinion. In order for these devices to do their job they must be a good fit and be worn properly. Since your knee is already hosed, a brace won't necessarily keep the ACL from tearing all the way, but it may buy you some time until you can schedule surgery, get time off work, save some cash to pay for the operation (and beer & DVD's to keep you entertained for all the couch time!) or whatever. Good luck with it.