This is a VERY familar injury for me as I have retorn my MCL on 4 different occasions. Usually if the MCL is the "only" problem, time, RICE treatment and a hinged brace will heal it without any surgery. Depending on the extent of the tear you are looking at anywhere from a few weeks to several months before it heals. I actually retore my MCL last year just trying to stay on a bucking horse. I found out later I also had a stress facture which could have been present before the injury as I also tore my ACL previously several years ago and haven't had it fixed yet. Last year's injury did cause a fair amount of swelling and bruising. I still have tenderness along that medial joint line to this day. My knee still buckles from walking, but that's because of the ACL injury. Once in a while I get a sharp pain in my medial compartment when I walk. I am only 32, but I wouldn't doubt if I have some early arthritis going on in that knee from years of my femur and tibia shearing against eachother with every collapse.
When I was younger after my first couple injuries, I was stupid and kept riding and playing rugby on my knee. I would go to physical therapy early in the morning so I could get to the barn before it got to hot. Last year, I took 3 months off because the weightbearing was an issue with the stress fracture.
It's been in my experience that riding by itself doesn't bother my knee a whole lot (I do hunter/jumpers), but any kind of unexpected thing like the horse spooking, bucking, tripping, over jumping is what causes it to buckle and I sometimes wind up with more swelling and pain after my lesson as a result. I tried riding in an over the counter hinged brace, but apparently that wasn't enough for me because of what happened last year, so now I ride in a functional brace designed specifically for ACL tears and it's saved my life several times. The downside to that kind of brace is that it is bulky and puts my leg in a weird position, plus it scratched my saddle until I made a few modifications, so it's a trade off.
I would definitely hold off on riding until you get a definitive answer. Make sure your ACL isn't also torn. It sucks, but knee injuries often lead to A LOT of problems long term if you don't treat them right away. I've been dealing with the aftermath of being stupid for the past 10 years and am only now starting to listen to my body.
Here are a couple pictures of the brace I wear now for riding. There's a picture of the bruising about 4days later and the swelling several hours after the injury before the bruising had a chance to set in.
Last edited by Equusketch; 08-10-2013 at 04:05 PM.