You cannot get the full truth simply through an interview. However, you can make your interiews more effective by asking specific questions which will help show interest and set you appart at the same time. We just finished with our first batch of interviewees this year, and it was really hard for me as a resident to tell if someone was interested if they didn't have anything to talk about or ask about the program. Don't make up questions just because you keep getting asked, "do you have any questions". However, there are some things you should probably ask.
If you want to operate a lot during your residency ask how many cases the 5th years have so far. Ask how much of the cases they generally do. Do they just do the approach and then mostly hold retractors while the real operation is happening as juniors (or seniors)? How many cases do they do in an average week? How many days of clinic do they do? Do the attendings always scrub every case or do they sometimes let the seniors take the juniors through the case? How many residents typically scrub one case (should be one and in rare cases two). Ask the second and third years how many total joints, IM nails, ankle ORIFs, arthroscopies and so forth they have done themselves with a senior or attending guiding them.
If you want to be the research guy/gal then ask how many papers the 5th years have published, etc.
If you want to know about lifestyle ask what they like to do outside of work. Do they have any hobbies as residents? Do they have families?
If you want to know about didactics ask what their average OITE percentiles run (be careful with this one, may want to ask program director rather than residents). Ask what their board passing rate is.
Specifics.
Keep your eyes open. How many residents at the night before gathering? Smiles or misery? Residents talk to each other or brush by one another coldly? Residents and faculty talk to each other comfortably or do the residents bow in reverence to the attendings, scared to speak directly to them.
As to the comment about fellows, I couldn't agree more. We have one fellow who does not work at the same hospital for the most part, thankfully. I'm very grateful not to have fellows around. If I had it to do again, I would rank programs with lots of fellows very low. Lots of fellows usually indicate big name surgeons with whom you'll not actually work directly much, but with whom you can say you worked as a resident when you interview for fellowship (which you will need to do so you can learn to operate).
