title: From the radiologic pathology archives imaging of osteonecrosis: radiologic-pathologic correlation.
abstract: Osteonecrosis is common and represents loss of blood supply to a region of bone. Common sites affected include the femoral head, humeral head, knee, femoral/tibial metadiaphysis, scaphoid, lunate, and talus. Symptomatic femoral head osteonecrosis accounts for 10,000-20,000 new cases annually in the United States. In contradistinction, metadiaphyseal osteonecrosis is often occult and asymptomatic. There are numerous causes of osteonecrosis most commonly related to trauma, corticosteroids, and idiopathic. Imaging of osteonecrosis is frequently diagnostic with a serpentine rim of sclerosis on radiographs, photopenia in early disease at bone scintigraphy, and maintained yellow marrow at MR imaging with a serpentine rim of high signal intensity (double-line sign) on images obtained with long repetition time sequences. These radiologic features correspond to the underlying pathology of osseous response to wall off the osteonecrotic process and attempts at repair with vascularized granulation tissue at the reactive interface. The long-term clinical importance of epiphyseal osteonecrosis is almost exclusively based on the likelihood of overlying articular collapse. MR imaging is generally considered the most sensitive and specific imaging modality both for early diagnosis and identifying features that increase the possibility of this complication. Treatment subsequent to articular collapse and development of secondary osteoarthritis typically requires reconstructive surgery. Malignant transformation of osteonecrosis is rare and almost exclusively associated with metadiaphyseal lesions. Imaging features of this dire sequela include aggressive bone destruction about the lesion margin, cortical involvement, and an associated soft-tissue mass. Recognizing the appearance of osteonecrosis, which reflects the underlying pathology, improves radiologic assessment and is important to guide optimal patient management.
authors.affiliation: From the Departments of Musculoskeletal Imaging (M.D.M., K.L.F., E.M.C.) and Pediatric Imaging (E.M.C.), American Institute for Radiologic Pathology, 1010 Wayne Ave, Suite 320, Silver Spring, MD 20910; Uniformed Services University of the Health Sciences, Bethesda, Md (M.D.M., E.M.C.); Department of Radiology, Walter Reed National Military Medical Center, Bethesda, Md (M.D.M., K.L.F., E.M.C.); Joint Pathology Center, Silver Spring, Md (M.K.K.F.); Department of Radiology, University of Virginia, Charlottesville, Va (M.G.F.); and Mayo Clinic Hospital, Phoenix, Ariz (M.J.K.).
authors.forename: Mark D
authors.initials: MD
authors.lastname: Murphey
authors.forename: Kristopher L
authors.initials: KL
authors.lastname: Foreman
authors.forename: Mary K
authors.initials: MK
authors.lastname: Klassen-Fischer
authors.forename: Michael G
authors.initials: MG
authors.lastname: Fox
authors.forename: Ellen M
authors.initials: EM
authors.lastname: Chung
authors.forename: Mark J
authors.initials: MJ
authors.lastname: Kransdorf
mesh_terms: D000369:Aged, 80 and over; D002471:Cell Transformation, Neoplastic; D002648:Child; D005260:Female; D006801:Humans; D007873:Legg-Calve-Perthes Disease; D008297:Male; D008875:Middle Aged; D010020:Osteonecrosis / Q000000981:diagnostic imaging* / Q000473:pathology* / Q000628:therapy; D011859:Radiography; D012720:Severity of Illness Index