My Father, 76, Was Diagnosed With Cancer In His Femur.

my father, 76, was diagnosed with cancer in his femur. He fell and broke his femur prior to the actual surgery date, where they planned to insert a titanium rod. He had surgery earlier than scheduled and they put a titanium rod in his femur. Since the surgery he has had constant pain. It appears the broken bones have shifted. What can we do to help him with the pain? Is this a surgical error?