a rare developmental abnormality of the skeleton in which metaphyses of tubular bones are expanded by deposits of cartilage.
met·a·phy·si·al dys·os·to·sis
(met'ă-fiz'ē-ăl dis'os-tō'sis) A rare developmental abnormality of the skeleton in which metaphyses of tubular bones are expanded by deposits of cartilage.