Pros & Cons of 7 day ortho service

I am currently forming a proposal to set up a 7 day working physio service in ortho.
If you have such a service, which types of patients are included elective/trauma or both?
Does it improve the efficiency of the service in terms of length of stay and do you have any audit results?
How long has the service been in operation and did you experience any problems when initially starting it up?
Who funds the service?
How do you train new staff and keep them up to date to manage weekend work?
If you not run a 7 day service why not?