Don't go overboard on this....you are not expected to know any more than the basics. I would seriously bone up on your joint exam skills and anatomy about the joints...in particular major nerves, muscle groups, and bone anatomy (eg trochanters). This sounds basic but it isn't. Given that 99% of med students aren't going into ortho, you will be most expected to know how to perform the exams, so have these down cold.
If you simply know how to do the exams and know your anatomy you will be golden. Even if you're heading for an ortho residency, this is the only stuff expected from ortho-bound med student rotators when starting the rotation.