nothing through fighting but from supplementary training.

Damaged knee cartilage. During a martial arts seminar.
Tore quadricep. Caused by over training, boxing session followed by heavy weights session followed by sprint workout, next day muscle soreness, went to kneel down and r-r-r-r-i-i-i-p-p-p-p, you can feel it tear up your leg. Now that was PAINFUL
I guess those are the worst, as yet not broken anything.