Well the Registrar got there about 10 mins before I did and had gone by the time I arrived.
Basically, they want to do the partial replacement next week (remove the femoral head and put a plastic spacer in), then it will be waiting until the infection is completely cleared before they complete the procedure.
They expect him to be in hospital for at least a week following the operation.
So the next step is to wait for the operation. I will update this when I know when that will be.