title: Spontaneous osteonecrosis of the knee.
abstract: Spontaneous osteonecrosis of the knee presents with acute onset of severe, pain in elderly patients, usually female and usually without a history of trauma. Originally described as idiopathic osteonecrosis, the exact etiology is still debated. Evidence suggests that an acute fracture occurs as a result of chronic stress or minor trauma to a weakened subchondral bone plate. The imaging characteristics on MR reflect the age of the lesion and the symptoms. More appropriate terminology may be " subchondral insufficiency fracture of the knee" or "focal subchondral osteonecrosis".
authors: Department of Radiology, Massachusetts General Hospital, MA, USA.
authors: Taj M
authors: TM
authors: Kattapuram
authors: Susan V
authors: SV
authors: Kattapuram
mesh_terms: D003937:Diagnosis, Differential; D005260:Female; D050723:Fractures, Bone / Q000175:diagnosis*; D006801:Humans; D007718:Knee Injuries / Q000175:diagnosis*; D007719:Knee Joint / Q000473:pathology*; D008279:Magnetic Resonance Imaging / Q000379:methods*; D008297:Male; D008875:Middle Aged; D010020:Osteonecrosis / Q000175:diagnosis*