The periphysis and its effect on the metaphysis. II. Application to rickets and other abnormalities.

The metaphyseal collar due to the periphysis is lost (in 98% of 49 subjects) as an early sign of rickets and returns with recovery. The term "pseudophysis" refers to that unossified metaphyseal osteoid and cartilage as in rickets. The collar is intact in metaphyseal chondrodysplasias (a helpful sign in differential diagnosis from rickets), is shortened in achondroplasia, and frequently is spared in osteomyelitis, luetic bone disease, and Caffey infantile cortical hyperostosis. The periphyseal bone bark is thinned, but often apparent, in rickets, and is not thinned in cases of tyrosinosis and phenylketonuria.