The association of spinal retroflexion with limb anomalies.

The spectrum of conditions in which retroflexion of the spine occurs includes anencephaly, iniencephaly, and Klippel-Feil syndrome. It was suggested by Gimour ('41) that a continuum may exist linking the latter two entities. The present paper attempts to reopen this question by reporting two specimens which have none of the above conditions, yet have spinal retroflexion and limb malformations. Combined with other isolated case reports, they show that spinal retroflexion can arise over a variable period of time.