no time to read all above - but if you were rotated in the fall some energy is transferred to pole moment of inertia. If you didn't break a bone most of the enrgy would have been transferred. Bones - particularly old bones - don't bend - especially round acute corners. You may still have bone damage - local crushing which will be lumpy even after the swelling/cushion subsides. But compared to the other possibilities that is a small problem.

Arnica is good at reducing haemoragging but not on broken skin.