Swelling, loss of function 8 weeks post fracture....hummmm couple things come to mind.
First off,,,in cast, external fixation device, was there and ORIF (surgical repair) done?
Second, how old is the person?? I would expect swelling loss of function more quickly in an older person.
Third, Are they compliant?? Keeping the extremity elevated?? Kids are bad about this. Also, many times some limited exercises, wiggling fingers, etc can help. Some external fixators allow certain amout of motion for rehad, while still maintaining alignment.
Last,,,is the reduction still in place, and healing well? How about follow up xrays. Sometimes people experience a non union, or mal union. I've seen some fall and re-break it, and come in wondering why the thing isn't healing!!
These are just off the top of my head thoughts. Hope that helps.