Metatarsus Adductus (also known as Metatarsus Varus) is a foot deformity (incidence 1 per 1000 births) noted in infants where the entire forefoot is turned inward.

The term metatarsus adductus describes a transverse plane deformity in which the metatarsals are medially deviated in relation to the longitudinal axis of the lesser tarsus, with the apex of the deformity at Lisfranc’s articulation (Yu and Wallace, 1987, p.324).  For a more detailed description, click here.
Yu, G.V. and Wallace, G.F.  1987.  Metatarsus adductus. In McGlamry, E.D. (Ed). Comprehensive textbook of foot surgery (volume one, first edition). Williams and Wilkins, Baltimore. pp. 324-353.