In radiology, the crescent sign is a finding on conventional radiographs that is associated with avascular necrosis.[1][2][3] It usually occurs later in the disease, in stage III of the four-stage Ficat classification system.[1] It appears as a curved subchondralradiolucent line that is often found on the proximal femoral or humeral head.[1] Usually, this sign indicates a high likelihood of collapse of the affected bone.[1] The crescent sign may be best seen in an abducted (frog-legged) position.[1][4]
A radiograph of a left hip joint, which reveals a thin, curvilinear lucent line parallel to the cortical margin of the femoral head, in a patient with avascular necrosis.
The crescent sign is caused by the necrotic and repair processes that occur during avascular necrosis.[1][2]Osteosclerosis occurs at a margin where new bone is placed over dead trabeculae.[1] When the trabeculae experience stress leading to microfractures and collapse, the crescent sign appears.[1]
The crescent sign may be seen with other bone diseases, such as shear fractures.[1]
Referencesedit
^ abcdefghiPappas, J. N. (2000). "The musculoskeletal crescent sign". Radiology. 217 (1): 213–214. doi:10.1148/radiology.217.1.r00oc22213. PMID 11012446.
^ abKenzora, J. E.; Glimcher, M. J. (1985). "Pathogenesis of idiopathic osteonecrosis: The ubiquitous crescent sign". The Orthopedic Clinics of North America. 16 (4): 681–696. doi:10.1016/S0030-5898(20)30435-1. PMID 4058896.
^Norman, A.; Bullough, P. (1963). "The Radiolucent Crescent Line--An Early Diagnostic Sign of Avascular Necrosis of the Femoral Head". Bulletin of the Hospital for Joint Diseases. 24: 99–104. PMID 14048829.
^"Rheumatology Image Bank: Avascular Necrosis, Crescent Sign: Ficat Stage III, Hip". Retrieved 26 June 2012.
January 01, 1970
crescent, sign, confused, with, crescent, sign, radiology, crescent, sign, finding, conventional, radiographs, that, associated, with, avascular, necrosis, usually, occurs, later, disease, stage, four, stage, ficat, classification, system, appears, curved, sub. Not to be confused with the air crescent sign In radiology the crescent sign is a finding on conventional radiographs that is associated with avascular necrosis 1 2 3 It usually occurs later in the disease in stage III of the four stage Ficat classification system 1 It appears as a curved subchondral radiolucent line that is often found on the proximal femoral or humeral head 1 Usually this sign indicates a high likelihood of collapse of the affected bone 1 The crescent sign may be best seen in an abducted frog legged position 1 4 A radiograph of a left hip joint which reveals a thin curvilinear lucent line parallel to the cortical margin of the femoral head in a patient with avascular necrosis The crescent sign is caused by the necrotic and repair processes that occur during avascular necrosis 1 2 Osteosclerosis occurs at a margin where new bone is placed over dead trabeculae 1 When the trabeculae experience stress leading to microfractures and collapse the crescent sign appears 1 The crescent sign may be seen with other bone diseases such as shear fractures 1 References edit a b c d e f g h i Pappas J N 2000 The musculoskeletal crescent sign Radiology 217 1 213 214 doi 10 1148 radiology 217 1 r00oc22213 PMID 11012446 a b Kenzora J E Glimcher M J 1985 Pathogenesis of idiopathic osteonecrosis The ubiquitous crescent sign The Orthopedic Clinics of North America 16 4 681 696 doi 10 1016 S0030 5898 20 30435 1 PMID 4058896 Norman A Bullough P 1963 The Radiolucent Crescent Line An Early Diagnostic Sign of Avascular Necrosis of the Femoral Head Bulletin of the Hospital for Joint Diseases 24 99 104 PMID 14048829 Rheumatology Image Bank Avascular Necrosis Crescent Sign Ficat Stage III Hip Retrieved 26 June 2012 Retrieved from https en wikipedia org w index php title Crescent sign amp oldid 1187629075, wikipedia, wiki, book, books, library,
