Multiple primary idiopathic scoliosis

This paper deals with a type of idiopathic scoliosis with more than two primary curves (three, four or five). These can be classified, together with double primary curves, under the general term "multiple primary idiopathic scoliosis", and should therefore replace "combined or double primary curves" in Schulthess' traditional classification. The author contends that the apparent rarity of multiple primary curves is due to inadequate observation, and discusses their etiology, clinical features, diagnostic criteria, natural history, prognosis and treatment.