What is a knee contusion?

Bad bruise of...: ...The bones of the knee, with damage to the soft tissues, but usually without fracture, cartilage, ligamentous, or tendinous damage. Responds well over 3-6 weeks of ice, elevation, sometimes compression, rest, arnica gel, initially followed by range of motion, heat, and pain relieving medications. Usually self resolving, but occasionally further work up and rehabilitation needed.