I tore my meniscus whilst running and it felt like an arrow going into my knee; couldn't walk so literally had to crawl to the car. Scans showed that it had a half an inch tear through it and had swelled up like a balloon.
About a week later, once it had settled down, I had key hole surgery to cut out the tear. Once there was no longer a leading edge on the tear it became stable and without pain, almost instantly.
I walked out of the hospital within a couple of hours, unaided, and ran a 10k ten days later.
Just a side, former England rugby full back, Jonathan Webb performed the surgery