Sounds like someone needs to leave their cell phone and pager at the desk, if they are company items, or not use them until she gets to her desk if they are personal. When they cry and bitch (They will) she can just show them the workers comp letter, and politely inform them that she is not working until she gets to her desk.
BTW, if you had to pay for surgery, you may want to get a lawyer involved. Weather or not it ends up as workers comp or not, the buisness is responsible to create a safe environment for employees and patrons. If they aren't putting down mats on a hospital floor (I think we have all seen how slippery those floors can be at one point or another), than it is a hazard to not only employees, but to customers as well. If Joe Shmoe walked in, fell, and needed surgery on his thumb because no one was cleaning the floors or didn't have a mat down etc. you would bet your butt he would have his treatment taken care of. Your wife should be treated NO differently.