I know a couple ortho guys who have done locums and they had widely different experiences. One went to a small town and basically, all they wanted him to do was see clinic patients and deal with any emergencies that came up related to the clinic. Basically, they wanted him to babysit the clinic for a week. They did not have him take call and he ended up doing one case for a septic joint.
The other guy went to an inner city hospital. They had just lost 2 of their staff orthopedists, who were employees of the hospital. This guy ended up doing trauma (ortho) shifts. I heard the story second=hand, but I believe they were 24 hr shifts, wanted him to do like 3 a week.