Was this a femoral shaft or femoral neck? You could use 27506 or 27507..or the code might not be reported at all. When did the fracture occur? Was it at the time of the joint replacement or at a different encounter?
If different encounter (i.e. patient fell some days before) then you could bill the 27506-79 or 27507-79. The 79 modifier indicating unrelated fracture.
If during the joint replacement, you can't bill for the fracture.