_Tenotomy and Forcible Correction under Anæsthesia._--In more severe cases we have to deal not only with the contracted soft parts, but with changes in the bones resulting from their having grown in adaptation to the deformed attitude. The majority of surgeons defer operative measures until the child is about a year old.
The soft parts to be divided are the tendo Achillis, the medial and posterior ligaments of the ankle, the plantar fascia, the calcaneo-navicular ligaments, and the tibialis posterior tendon. The varus deformity may then be corrected by laying the foot on its lateral side on a padded triangular wooden block, and pressing forcibly on the anterior and posterior ends of the foot so as to undo the curve on its medial side and allow of abduction of the foot; this is usually attended with cracking as the shortened ligaments give way. The equinus element is next dealt with by forcibly dorsiflexing the foot until the deformity is over-corrected. If it is preferred to correct the deformity in stages instead of at one sitting, the equinus element is left to the last. In older children, the strength of the hands is usually insufficient to stretch the tissues, and mechanical wrenches may be employed, such as those devised by Thomas, Bradford, or Lorenz.
_Resection of a wedge from the tarsus_ (Davies Colley, 1876) is reserved for the most severe cases in which the shape and rigidity of the bones prevent correction of the deformity by any other means. The base of the wedge is on the lateral aspect, and the bone removed includes parts of the calcaneus, cuboid, talus, and navicular.
_Removal of the talus_ is an alternative operation to resection of the tarsus, and may yield equally good results.
In children, before the tarsal bones have become completely ossified, Ogston's method yields good results; instead of removing a wedge from the tarsus, the osseous nucleus of each bone is gouged out, leaving the cartilaginous shell. In this way the intertarsal joints are not interfered with, and the cartilaginous tarsus can be moulded so that when ossification is completed the bones differ but little from the normal.
After any of these operative procedures, manipulations, massage, exercises, electrical stimulation of the muscles, and the wearing of some apparatus must be persevered with for at least twelve months. Failures are due to not sufficiently over-correcting the deformity in the first instance, and to neglect of after-treatment; in hospital practice it is difficult to ensure continuous supervision over long periods.