You need a knee brace, preferably the kind with an assist. Hinged Knee Brace: Shock Doctor Maximum Support Compression Knee Brace https://www.amazon.com/dp/B00598YB3A/ref=cm_sw_r_apan_glt_fabc_STWTAJ2J16KQSQ9K3J9S
Preferably one similar to this.
When I first got my knee braces I used a silicone backed hook & loop tape to keep them in place. Hooks toward the inside of the brace and adhesive towards the skin. Does a pretty good job of keeping the brace in place and it doesn't leave residue. I ended up getting something like this after dealing with the typical elastic/velcro knee braces. It does pretty well for me.
I've torn my left ACL (or its replacement) 3 times now and currently it is not repaired. Got a hamstring autograft the first time with some meniscectomy (Dec 2010), cadaver achilles allograft the second time (July 2011), and then didn't have surgery the third time (August 2013), despite having a complete tear. I still play some sports (though not rugby, which is how I tore it the first and third times), and only really wear a brace when playing football. I've also definitely had to change how I play. I'm a lot slower on the turn (may be psychological, but still), I am quicker to pull out of challenges, and I can occasionally feel a slight buckle or shift in my knee and even though it isn't painful, it scares the shit out of me every time.
After trying a bunch of different braces over the years, I've found this to be the best one by far. It fits well, stays in place pretty well, and it's not all that uncomfortable.
I injured my knee back in August. Sprained (torn maybe) MCL. I went to physio for 4 weeks or so (didn't get an MRI), and gently started going back on the mats with a really good knee brace with hinges. I had / have to really listen to my body now and hold back sometimes if I feel my knee going sketchy after a few days of hard training.
It feels stronger as time goes on but I'll be wearing this for a while as a precaution. I'm close to blue belt and I don't want a major injury to set me back.
Anyways the knee brace is the Shock Doctor 875 "Ultra Knee Supporter with Bilateral Hinges". Here's a link to Amazon where I bought it.
It's way solid and keeping me out of trouble.
What did the doctor recommend you do now? Just rehab or surgery too? Anyways, take some time off to heal so it doesnt get worse. I tore my ACL and had it replaced in 2012. After rehabbing and getting clearance I got back on the mats with this brace: http://www.amazon.com/Shock-Doctor-Supporter-Bilateral-Hinges/dp/B00598YB3A/ref=sr_1_1?ie=UTF8&qid=1397926594&sr=8-1&keywords=acl+brace
I read somewhere that no brace off the counter can truly protect you from injury. The brace is effective at reminding you to not be a hero and pushing yourself too hard though.
This one has dual hinges, is not as clunky as the DonJoys, and doesn't have exposed plastic or metal: http://www.amazon.com/dp/B00598YB3A/ref=pe_385040_30332200_pe_309540_26725410_item
what about knee braces with a bilateral hinge to keep outward movement of knee?
Do you use knee braces?