How can you fix a broken knee?

Depends: It depends on the level and nature of the fracture. If it's a complicated fracture, it may need to be surgically repaired. If it is not, then one may be placed in a cast. Your orthopedic specialist should be able to give you a plan of action.

Depends: Not sure what a broken knee is, but it you have had an injury and your knee is swollen, it should be evaluated by an othopedic surgeon asap.