Nonunion
（重定向自Non union）
Nonunion is permanent failure of healing following a broken bone.
Nonunion is a serious complication of a fracture and may occur when the fracture moves too much, has a poor blood supply or gets infected. Patients who smoke have a higher incidence of nonunion. The normal process of bone healing is interrupted or stalled. In some cases a pseudo-joint (pseudarthrosis) develops between the two fragments with cartilage formation and a joint cavity. More commonly the tissue between the ununited fragments is scar tissue.