Netter's Concise Atlas of Ortho Anatomy is the LAW for the sub-I's.
I'd highly advise sub-Is to ask their residents what approaches may be used for the next day's cases, and to look over Hoppenfeld surgical exposures each night (with an anatomy book also) before your cases. This will tell you what internervous planes are used, and what structures are at risk. Combined with anatomy this is PRIME pimp material in the OR.
Of course the fracture handbook is also key for trauma rotations, or when taking trauma call when on other services (which is a great way to meet other residents).