This stage lasts up to 7 days. When a bone is fractured, blood leaks out through torn vessels in the bone and forms a haematoma between and around the fracture. The periosteum and local soft tissues are stripped from the fracture ends. This results in ischaemic necrosis of the fracture ends over a variable length, usually only a few millimetres. Deprived of their blood supply, some osteocytes die whereas others are sensitised to respond subsequently by differentiating into daughter cells. These cells later contribute to the healing process.