I am not an orthopedic surgeon. That being said, if it really is a nonunion there is no universal way that it is treated because it depends on so many factors--location of the fracture, symptoms, level of present function, level of desired function, etc. Your friend really should see an orthopedic surgeon to talk it over.
My friend didn't get much advise from the orthopedic surgeon, not even a sling!... It was broken 4 days when the doctor 1st saw it. Dr seemed to think it would heal... Kept telling me to come back, but it didn't seem worth the money just to see another xray w no change. Just curious if anyone had that injury (I guess not). And how much does it cost to get it plated? I'm guessing its more than I got and it doesnt bother me much. I'll try to get another doc to look at it.