Sound like a strange question coming from a fellow Physio who used to work in NSW. I imagine you'll be treated like anyone else who has to have time off work for a joint replacement. In our line of work I would think that you would definitely get your job back as I can see no reason why you couldn't still work as a physio. Of course some activites you couldn't do but if you had a knee resurfacing then you'll have excellent range and function following and within 3 months.

So what is your real worry here?