title: Prognosis of early stage avascular necrosis of the femoral head.
abstract: Seventy-two femoral heads in 63 patients in whom avascular necrosis of the femoral head was in the early stage were followed up prospectively for a mean period of 6 years 1 month. All of the necrotic lesions were confirmed by magnetic resonance imaging. At the time of final outcome, 46 (64%) of the 72 hips were symptomatic. Necrotic lesions greater than 2/3 of the weightbearing portion on T1 weighted central coronal images indicated a high risk of clinical deterioration. Fifty-nine of the 72 hips initially had necrotic lesions greater than 2/3 of the weightbearing portion, and 44 (75%) of these 59 hips were symptomatic at the final outcome. However, in the radiographic assessment of 15 (25%) asymptomatic hips, even when the necrotic lesions were greater than 2/3 of the weightbearing portion as shown by magnetic resonance imaging, the continuous absence of any radiographic abnormality indicated the possibility of a continuous asymptomatic stage for at least several years.
authors.affiliation: Department of Orthopaedic Surgery, Hokkaido University, School of Medicine, Sapporo, Japan.
authors.forename: H
authors.initials: H
authors.lastname: Ito
authors.forename: T
authors.initials: T
authors.lastname: Matsuno
authors.forename: K
authors.initials: K
authors.lastname: Kaneda
mesh_terms: D000328:Adult; D005260:Female; D005271:Femur Head Necrosis / Q000145:classification / Q000175:diagnosis* / Q000000981:diagnostic imaging; D006801:Humans; D008279:Magnetic Resonance Imaging; D008297:Male; D008875:Middle Aged; D011379:Prognosis; D011446:Prospective Studies; D011859:Radiography