If the fracture does not heal, the fracture may not heal due to improper treatment. Patients treated conservatively may have soft tissue embedded in the fracture end, which may lead to fracture non-union at a later stage, or excessive traction during conservative treatment may lead to bone non-union. In patients treated surgically, the fracture may not heal due to excessive periosteal stripping affecting the blood flow at the fracture end, which may be caused by unstable internal fixation or secondary to postoperative infection, or due to severe contamination from an open fracture, which may lead to osteomyelitis at a later stage. It can also be due to poor nutrition, such as low albumin due to self or liver disease, or poor peripheral blood flow due to diabetes mellitus, or to severe comminuted fractures, where the fracture does not heal due to severe bone loss.