In reply to Dominicandave:
Possible complications or realistic outcomes?
Possible - bleed to death from the fracture, osteomyelitis or devastating infection at open fracture site (regardless of current AB's), mal or non union of the fractured femur at later date.
Reality - there will already be new regeneration at the fracture site, but it won't be set bone at this point. A good medevac to a clinical care venue and a good Orthopaedic surgeon should see the patient do OK in the long term.
Other factors involved, is the patient local, contracted in, have available medical help on call? Possibly not from the OP.
If the fracture has been pinned (even at 3 weeks) it should bode well for a good recovery.
Feel free to email me.