Can you tear your fibular collateral ligament ? and what is usually done for it?

Yes: Yes, in fact it is a fairly common sports injury! First Aid involves 'R.I.C.E.S' (Rest Ice Compression, Elevation, Support). If it is a partial tear, the leg is usually placed in a knee immobilizer or pt may need crutches, followed by physical therapy. If it is a complete tear, then it needs to be repaired surgically followed by physical therapy, or you will have chronic joint instability,