Accessory soleus muscle in clubfoot deformity: a report in four feet

The commonest presentation of accessory soleus muscle is a swelling at the posteromedial aspect of the ankle in adolescents or young adults. Accessory soleus is rarely encountered in children undergoing surgical release for congenital clubfoot, and only a few isolated reports are available in the literature. The purpose of this study is to heighten awareness about the role of accessory soleus muscle in clubfoot deformity. Four cases of accessory soleus muscle in patients undergoing surgical release for clubfoot deformity are reported here in which, a distinct anomalous muscle deep to the tendoachilles was identified. Hindfoot varus and equinus persisted in each of these cases despite an adequate posteromedial soft tissue release, which could be corrected only on tenotomizing the tendon of the accessory soleus muscle at its insertion. An awareness about the accessory soleus muscle is important, particularly when non-operative methods of clubfoot management with tendoachilles tenotomy or limited surgery are employed. Failure to recognize this muscle if present in patients with congenital clubfoot may lead to persistent hindfoot deformity. A high index of suspicion should be maintained in cases in which hindfoot deformity persists despite an otherwise adequate soft tissue correction.