text: <unk>  is permanent failure of healing following a broken bone.<unk>  is a serious complication of a<unk>  and may occur when the<unk>  moves too much, has a poor blood supply or gets infected. Patients who smoke have a higher incidence of<unk> . 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.
  Since the process of bone healing is quite variable, a<unk>  may go on to heal without intervention in a very few cases. In general, if a<unk>  is still evident at 6 months post injury it will remain unhealed without specific treatment, usually orthopedic surgery. A<unk>  which does go on to heal is called a delayed union.
option_0: Fracture nonunion
option_1: Stress fracture
option_2: Pseudarthrosis
option_3: Occult fracture
option_4: Synarthrosis
option_5: Compression fracture
option_6: Ankle fracture
option_7: Osteochondrosis