Some surgeons (who, these days, happen to hold the degree of MD) still find the "mister" thing respectful of their specialty. Sure, it may be a hangover from a

Some surgeons (who, these days, happen to hold the degree of MD) still find the "mister" thing respectful of their specialty. Sure, it may be a hangover from a time long past when surgeons usually weren't qualified physicians, but now it signifies that you understand they aren't "mere" GPs/physicians attending. (Interesting note only, not a rebuttal.)