Imaging of early stages of osteonecrosis of the knee.
Osteonecrosis of the knee can present as a spontaneous and primary or a secondary clinical entity. The natural history of osteonecrosis follows a course of several sequential stages, and the later stages of both entities seem to be irreversible. Early diagnosis of osteonecrosis is crucial: the earlier the stage of the lesion at the time of diagnosis, the better the prognosis.Clinically, early diagnosis and treatment of osteonecrosis might prevent unnecessary surgery in cases with a concomitant degenerative meniscal tear. Early-stage osteonecrosis should be ruled out before surgery, because arthroscopy has lately been associated with osteonecrosis. Not every imaging method is equally suitable for detecting pathognomonic changes in each stage of osteonecrosis. Early-stage osteonecrosis is difficult to diagnose,because various differential diagnoses must be kept in mind. Moreover, there is a diagnostic window between the onset of symptoms and the appearance of pathognomonic changes on plain radiographs and MRI.
Pape
Dietrich
D
Department of Orthopaedic Surgery, University of Saarland, Kirrbergerstrasse, 66421 Homburg/Saar, Germany. dietrichpape@yahoo.com
Seil
Romain
R
Kohn
Dieter
D
Schneider
Gunther
G
D000328:Adult; D000367:Age Factors; D000368:Aged; D003952:Diagnostic Imaging / Q000379:methods*; D018450:Disease Progression; D005260:Female; D005500:Follow-Up Studies; D006801:Humans; D007719:Knee Joint / Q000473:pathology*; D008279:Magnetic Resonance Imaging / Q000379:methods; D008297:Male; D008875:Middle Aged; D010020:Osteonecrosis / Q000175:diagnosis*; D011877:Radionuclide Imaging / Q000379:methods; D018570:Risk Assessment; D012680:Sensitivity and Specificity; D012720:Severity of Illness Index; D012737:Sex Factors