I've seen the surgeon, 3 nurses and a high-school work experience student. Nice chap (the surgeon).
Surgeon already knew what was wrong, from the last x-ray.
Hospital had cocked up with my wrist. The main fracture in my radius has healed at an angle, putting my whole hand at an angle to my forearm and displacing it relative to the ulna (hence the ulna flapping around in mid air).
The solution is to saw through my radius, cut a wedge shape, graft in some bone from my hip and fix it all in place with plates.
On waiting list for surgery, should take place in 2-3months.