Risser Staging System of Skeletal Maturity

The Risser staging system is used to assess the skeletal maturity of an adolescent, especially in patients undergoing surgery to correct scoliosis.

Radiologic exam: iliac crest apophysis (of the os coxa), usually the non-dominant side

X-Ray Appearance	Risser Stage
no apophysis along the iliac crest	0 (immature)
apophysis ossified over 25% of the iliac crest	1
apophysis ossified over 50% of the iliac crest	2
apophysis ossified over 75% of the iliac crest	3
complete ossification of the iliac apophysis without fusion to the iliac crest	4
fusion of the iliac apophysis to the iliac crest	5 (adult pelvis, mature)

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