This document summarizes principles of fracture fixation, methods that provide absolute versus relative stability, and Perren's strain theory. Absolute stability results in primary bone healing without callus formation, while relative stability stimulates callus formation and secondary bone healing. Simple fractures benefit from absolute stability using techniques like lag screws or compression plates, while multifragmentary fractures typically use relative stability with bridging plates, intramedullary nails, or external fixation. The goal is anatomical reduction and rigid fixation for intra-articular fractures, and alignment with relative stabilization for multifragmentary diaphyseal fractures.