Dr. Z said:
I agree with Supercut. My friend who recently returned from a 3 month mission with Doctors Without Boarders performed mostly general surgery cases. However, he did have to perform other operations (ortho, neuro, optho, gyn) that are normally not done here in the US by general surgeons. Based on what he told me, I would expect that unless you are trained in general surgery (with a couple of extra rotations in ortho and neuro surg) you would have a difficult time being the only surgeon on a mission. He also told me that they like to send only one surgeon on a mission at one time. I think that an ortho trained surgeon would feel rather lonely when a GSW to the abdomen shows up in the ED.
Also, if you are interested in this type of mission work you might want to read "The Dressing Station: A Surgeon's Chronicle of War and Medicine" by Jonathan Kaplan. It is an interesting read. Hope this helps.