The<unk>  is an indirect measure of skeletal maturity, whereby the degree of ossification of the iliac apophysis by x-ray evaluation is used to judge overall skeletal development. Mineralization of the iliac apophyses begins at the anterolateral crest and progresses medially towards the spine. Fusion of the calcified apophyses to the ilium then progresses in opposite direction, from medial-to-lateral. A typical five-point grading scale is as follows: * Grade 1 is given when the ilium (bone) is calcified at a level of 25%; it corresponds to prepuberty or early puberty. * Grade 2 is given when the ilium (bone) is calcified at a level of 50%; it corresponds to the stage before or during growth spurt. * Grade 3 is given when the ilium (bone) is calcified at a level of 75%; it corresponds to the slowing of growth. * Grade 4 is given when the ilium (bone) is calcified at a level of 100%; it corresponds to an almost cessation of growth. * Grade 5 is given when the ilium (bone) is calcified at a level of 100% and the iliac apophysis is fused to iliac crest; it corresponds to the end of growth.<unk>  grading is traditionally used to estimating the future growth potential of the adolescent spine, particularly in the setting of spinal scoliosis.<unk>  originally recognized that ossification of the iliac apophyses approximately parallels the ossification of the vertebral apophyses. The earlier the stage of growth, the greater the likelihood of a scoliosis progressing and potentially needing intervention. Note that although<unk>  first described his findings during a 1948 lecture and published the eponymous paper in 1958, formalized staging systems were developed at a later time.
Risser sign
Amsler sign
Crescent sign
Sulcus sign
Steeple sign
Markle sign
Chvostek sign
Westermark sign