"Howard Haldeman Steel (1921-2018) was an American paediatric orthopaedic surgeon who described the sign in an article published in 1986 1,2."
"The 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 the superposition of the femoral neck and the posteriorly displaced capital epiphysis."
"History and etymology"