This document discusses stages of perilunate injuries from stage 1 to 4, with stage 1 being scapholunate dissociation and stage 4 being lunate dislocation. It also covers carpal bone anatomy, ligaments, signs associated with each stage like Terry Thomas and apple signs, Mayfield staging system, greater and lesser wrist arcs, and emergency and definitive treatment options like reduction, nerve decompression, and stabilizing the lunate.