title: Avascular necrosis of the dens: a follow-up study.
abstract: In order to determine the long-term consequences of avascular necrosis of the dens following halo-pelvic traction, 83 patients who had had their halo-pelvic apparatus removed at least five years previously were studied. Avascular necrosis of the dens was found in 31 patients (37%) within one year of removal of the apparatus, but after a minimum of five years the early bony changes had resolved and there was no evidence of atlantoaxial instability. However, 19% of patients who had had avascular necrosis had moderate or severe neck symptoms.
mesh_terms: D000293:Adolescent; D001368:Axis, Cervical Vertebra / Q000000981:diagnostic imaging; D005500:Follow-Up Studies; D006801:Humans; D008297:Male; D010020:Osteonecrosis / Q000209:etiology*; D010384:Pelvic Bones; D011859:Radiography; D013122:Spinal Diseases / Q000000981:diagnostic imaging / Q000209:etiology / Q000628:therapy; D014143:Traction / Q000009:adverse effects*