Accessory soleus muscle as a cause of resistance to correction in congenital club foot: a case report.

A 14-month-old female with bilateral clubfeet was initially treated by serial casting and percutaneous tenotomy of the Achilles tendon, bilaterally. Both clubfeet subsequently underwent surgical treatment with a posteromedial release through a Cincinnati incision. At surgery on one clubfoot, an accessory Soleus muscle was found anterior to the Achilles tendon with a distinct insertion on the upper surface of calcaneus, anterior and medial to the insertion of Achilles tendon. This accessory Soleus muscle may have been the cause of resistance to correction in this congenital clubfoot.