THE REGION OF THE ANKLE AND FOOT 495 



(3) Talipes Yarns. When the condition is congenital, the 

 tendons of the tibialis anterior and posterior are shortened, and 

 the distal part of the tibial diaphysis is twisted slightly in a 

 medial direction. When the condition is acquired, it results 

 from the tonus of the tibialis anterior following paralysis of the 

 peronaeus longus or brevis, or of both these muscles. 



(4) Talipes Valgus. In the congenital variety the peronsei, 

 longus, brevis, and tertius, are shortened while the two tibiales 

 are overstretched. The acquired variety is due to paralysis 

 of both the tibialis anterior and the tibialis posterior. 



In the combined varieties, the muscles of more than one 

 compartment are involved. Thus, in acquired talipes equino- 

 varus, the peronsei are affected together with one or more 

 muscles of the anterior compartment. The highest degree of 

 the deformity is produced when all the muscles of both com- 

 partments are paralysed. 



In congenital talipes, the treatment should be based on the 

 degree of the deformity. In minor deformities, methodical 

 manipulations, which tend to overcorrect the faulty position, 

 and possibly the use of a light splint, may be sufficient. When 

 the deformity is more pronounced, the manipulations must be 

 more vigorous, and tenotomy of the shortened structures 

 may be necessary before the foot can be wrenched into better 

 position. In the worst cases operative interference, such as 

 excision of the talus or the removal of a wedge-shaped portion 

 from the tarsus (cuneiform tarsectomy), alone will produce 

 correct alignment. 



Cuneiform Tarsectomy. The position of the wedge of 

 bone removed in cuneiform tarsectomy depends on the nature 

 of the deformity. In talipes equino-varus , the base of the wedge 

 is on the lateral border of the foot. The incision, which divides 

 the nervus suralis and the small saphenous vein, is carried 

 backwards and laterally from the prominent head of the talus 

 to the calcaneus. The skin and fasciae are undercut, and this 

 step exposes the medially displaced extensor tendons at the 

 medial extremity of the wound and the extensor digitorum 

 brevis at the lateral extremity. The lateral part of the cruciate 

 ligament (p. 470) is divided and turned medially, together with 

 the extensor digitorum brevis, which is elevated from the 

 calcaneus. The extensor tendons are retracted, and a sharp 

 gouge is thrust horizontally through the lateral surface of the 

 calcaneus into the talo-navicular joint. The gouge is next 



