The bone is cut (osteotomy) and then an external or internal fixator is used to slowly pull the two bone segments apart. In this video, a monolateral external fixator is used to lengthen the bone. The process of slowly pulling the bone segments apart is called distraction. During the distraction phase, new bone that is called regenerate bone forms in the space between the bone segments. After the bone has been lengthened, the consolidation phase starts. The regenerate bone slowly hardens during the consolidation phase. After the bone has fully consolidated, the internal or external fixator can be removed.