Congenital vertical talus: classification with 69 cases and new measurement system.

Sixty-nine cases of congenital vertical talus (CVT) were classified into five groups in association with (1) neural tube defects or spinal anomalies, (2) neuromuscular disorders, (3) malformation syndromes, (4) chromosomal aberrations, and (5) idiopathic CVT unassociated with any of the systemic conditions described above. Forty-four cases of idiopathic CVT were subclassified into four groups: (5A) intrauterine molded or deformed cases, (5B) cases of digitotalar dysmorphism associated with contractile finger abnormalities and genetic inheritance, (5C) patients whose close relatives had CVT or oblique talus (OT) deformity, and (5D) cases unassociated with any skeletal deformity or genetic inheritance. The talar and Calcaneal axis--first metatarsal base angles (TAMBA and CAMBA) are introduced, which enable us to describe not only the obliquity of the talus and calcaneus but also the severity of the dislocation of the talonavicular joint and the contracture of the tendo Achilli. The changing point from flexible OT to rigid CVT is TAMBA of about 60 degrees and CAMBA of 20 degrees, and there are many borderline cases of CVT that could be treated conservatively. For the typical CVT, open reduction should be carried out as promptly as possible if 3 months of corrective casting in extreme equinovarus fails to reduce the TAMBA to 50 degrees.