Tibial spastic varus foot caused by os calcaneus secundarius: A case report.

Peroneal spastic flatfoot caused by tarsal coalition is well known; however, tibial spastic varus foot is a rare clinical entity also caused by tarsal coalition in most cases. The os calcaneus secundarius is a rare accessory bone between the anterior process of the calcaneus and the navicular bone. The case of a 29-year-old woman with tibial spastic varus foot caused by os calcaneus secundarius is presented. Operative excision of the os calcaneus secundarius completely resolved the varus deformity. This is the first case report involving tibial spastic varus foot caused by os calcaneus secundarius.