I've had multiple meniscus tears on both knees, multiple surgeries, ACL reconstruction on both, and countless other injuries to the knee(s). I know numerous others that have had the same or more.
If your doctor did a McMurray Test on your knee, that should have established a "tear." Sending you for an MRI is great so you see the extent, large or small.
The meniscus can tear in many different ways. Usually–and from what it sounds like in your case—they are small tears. Even a tear of a few millileters can cause serious pain and immense swelling. Stay off of it for now and just be careful when you step... your knee is weak and you don't want to make things worse.
If you need surgery—and, there's good chance you do—it's definitely going to be arthroscopic (unless you shredded it—and, you didn't shred it). "Suturing," as mentioned in previous post, could be a possiblity, but these "tears" more so occur on the edge of the meniscus. Likely, there is a small couple millimeter tear that will need to be "shaved." The remainder of your meniscus will remain and work like normal. The second time I tore my right meniscus, it was shredded, like "bear-clawed," and was removed completely instead of "sutured." I still f-in do heavy legs today.
Arthroscopic surgery is outpatient... you go in morning, come out afternoon. If you take therapy seriously (you will), you can recover from it within 2 to 4 weeks. These types of injuries are more of a pain in the ass than something life altering.
During therapy, your therapist will work on regaining "range of motion" and re-strengthening your ligaments/tendons (i.e. patellar tendon) and muscles (your quadricep will atrophy from the arthroscope— don't worry, comes back fast). After your therapy period, you're knee and leg will still be a little weak... that's when you ease into training again.
If you give me more info about what happened, what your doctor said, how you fell/twisted your knee, and where you felt/feel the pain, I can tell you more.
