A fractured hand is actually [i]really[/i] difficult to heal, since there's so many small bones and sensitive tendons in the hand. Any problems associated with fixing a fractured arm bone are amplified when you relocate the fracture to a place that's more sensitive, softer, and much more difficult to operate on without causing irreparable damage.

A dislocated shoulder, finger, or elbow would be the safest and easiest injuries to have.