The metaphyseal blanch sign (a.k.a. metaphyseal blanch sign of Steel) is one of the signs seen on AP views of the adolescent hip indicating posterior displacement of the capital epiphysis.
It is a crescent-shaped area of increased density, that overlies the metaphysis adjacent to the physis on the AP radiograph. It is caused by superposition of the femoral neck and the posteriorly displaced capital epiphysis.
A lateral radiograph is indicated to confirm or exclude the suspected diagnosis.
History and etymology
Howard Haldeman Steel (b. 1921) is an American paediatric orthopaedic surgeon, who described the sign in an article published in 1986.
- 1. Steel HH. The metaphyseal blanch sign of slipped capital femoral epiphysis. J Bone Joint Surg Am. 1986;68 (6): 920-2. Pubmed citation