Why can't the arm be straightened after the forearm fracture is put with steel plate?
I don't think so. My hand used to be like this, mainly because the steel plate pressed against the nerve or tendon. This is my idea. You've been saying this for so long, I suggest you go to the hospital to find a doctor, ask a question and make a film, so you can see it clearly. If any doctor still says that, you can go to other hospitals and ask other doctors.