What Does Joint Effusion Mean On MRI?

Hi, may I answer your health queries right now ? Please
type your query here...Hi, i am a 19 year old male . I play m.m.a and giugitsu " kind of mixed martial arts " , recently I hurt my left knee ,I had an m.r.i the report said " tear affecting posterior horn of the medial meniscus .
The lateral collateral ligament appear distorted which represent partial tear .
lateral meniscus , both cruciate ligaments , medial collateral ligament and the patellar ligament appear intact .
minimal amount of joint effusion ."
what does all this mean ? what should I do ? can I keep training ?
help me please because my future depends on this .