Plantarflexion lateral stress radiographs in diagnosis of congenital vertical talus. A, In normal foot, long axis of first metatarsal passes plantarward to long axis of talus. B, Forced plantarflexion lateral demonstrates inability of first metatarsal to line up with the talus. C, After 5 weeks of casting the plantarflexion lateral demonstrates good alignment of the first metatarsal and talus. D, After percutaneous pinning of talonavicular joint and percutaneous Achilles tenotomy.