while I respect that jules may have had a different interview experience than I just had, I couldn't disagree more.
yes, all the B.S. that was mentioned ("where did you do you aways?") of course gets brought up. this is a given, but rarely do these topics lead to any kind of meaningful discussion. some of the best conversations I had on my interviews dealt with my extracurriculars, especially those in which I participated during my M1 and M2 years. even some things I did as a high school student were brought up. the sentiment that these activities "will never get noticed or mentioned" is misleading and untrue, in my opinion.
I agree that you shouldn't spread yourself too thin. don't sacrifice your academic performance for the sake of myriad extracurriculars. at the same time, please don't let yourself become some AOA-mongering individual who becomes one-dimensional because of some idea of what "residency directors want to see."
as a ms2, you should focus on learning what you need to become a good doctor. of course, do some shadowing/research in ortho if you want, but realize that your goal should be to learn the pathophysiology that is necessary to become an excellent physician. not only will this help you to score well on step 1, but you'll be a much better clinician as a result (regardless of the field you ultimately choose). your experience with ortho will come mostly during your 4th year. this is true for most everyone, and you will not be at a disadvantage.
there's more to life than tests. there's more to your career than AOA. spend the extra hour here and there doing some tutoring or participating in student leadership. take a night off and play some IM broom ball or basketball with your classmates. go talk to some high school kids about what fascinates you about your education. relax on a saturday night and pound some brews. whatever.
you'll do fine. keep up with your classes, do what interests you, and stop worrying about what some application reviewer will think two years from now. you'll thank yourself, I promise.