Is A Full Arm Cast Or Surgery Advisable For Broken Ulna?

My husband broke his ulna 2 months ago. He was put in a full arm (past the elbow) cast and has been in it since then. Last visit, they mentioned surgery because it wasn't healing as fast as they'd expect. But when we went back, they put him in just a fore arm cast, below the elbow. He is now in pain again. The x ray still looked like it was broken, but the doctor said there was callousing, and that was good. Does my husband need to be in a full cast again, or need surgery? I don't think he should be in pain!