you have a duty to provide 24-7 call coverage for your clinic patients. Depending on your arrangements (other drs in your practice or in the community you agree to swap call with) you could be on call constantly. This is ususally a mere inconvenience....I go days or even weeks at a time with no calls from clinic pts. The ones that do occasionally call are usually utter nonsense that can be handled with a 2 minute phone call. Hospitals are a different beast altogether, and again depends a lot on the individual arrangements. you can literally be on call as much as you want....or maybe as little as you want. There are OMS who are not on staff at any hospital...no call. There are some who are on staff at hospitals that may not have a formal call arrangement. There are some who are on staff at hospitals with formal call schedules who wiggle out of cases they don't want. Hospital trauma/pus call canrange 0-365 days a year.
and, incidentally, I agree w/ mrrongeurs....you don't have to be the plate-wielding beast-mode trauma freak to desire a career in OMS. You just have to be one for 4-6yrs. once you are in private practice, you generally have a large degree of autonomy in crafting the practice you want.