Sequestration and Involucrum Understanding Bone Necrosis and Revascularization in Pediatric Orthopedics

Sequestration is an area of devascularized bone that heals through the same coordinated team of cells as a fracture to resolve hypoxia, promote vascular ingress, and finally, ensure mechanical stability through bone formation. Sequestration differs from fracture healing in its drastically reduced strain to stimulate endochondral angio-genesis/ossification for repair and typically, an intact periosteum. Intact periosteum, when pre-sent, acts as a vascular anastomosis around the avascular space and is a robust supply of vessels for arborization and stem cells, which helps to improve healing. Understanding the bone and vascular biology underlying the sequestration healing has direct implications for clinical management and treatment