Achilles Tenotomy (Percutaneous Heel Cord Tenotomy)
The Achilles tenotomy is an integral part of Ponseti management of clubfoot. Tenotomy is necessary because the Achilles tendon, unlike the ligaments of the foot, is made up of thick, non-stretchable fibres. After the tenotomy the foot is placed in a final cast in an over-corrected position of maximal abduction and dorsiflexion. The tendon re-grows in this lengthened position, allowing the range of motion needed at the ankle joint. Achilles tenotomy is required in around 80-95% of patients and should be performed when complete correction of adduction deformity is achieved but equinus deformity remains. For a detailed explanation of how to assess when Achilles tenotomy is required and how to perform the tenotomy please refer to the Global HELP manual.
Some clinicians have expressed concerns about performing a complete tenotomy (completely severing) of the Achilles tendon, fearing this procedure will cause damage. However, an ultrasound study on children who had undergone Achilles tenotomy as part of their clubfoot treatment showed tendon re-growth; most tendons were clinically intact after 3 weeks and after 6 weeks all were intact (30). Even in a study of older children (7-11 years old) Achilles tenotomies were performed on all participants; none of the participants had weakness of the gastrocnemius or soleus muscles (31). The maximum age when tenotomy can be used has not been established, however, so the authors suggested that a lengthening procedure using three incisions could be used in place of complete tenotomy in older children (31).