Manual of Surgery Volume Second: Extremities—Head—Neck. Sixth Edition.

by Alexis Thomson; Alexander Miles

Fig. 146.—Extreme form of Pes Equinus in a girl æt. 8, the result of Anterior Poliomyelitis.

Fig. 147.—Skeleton of Foot from case of Pes Equinus due to Poliomyelitis.

Clinical Features.—In the mildest cases the patient is able to bring the foot to a right angle. In average cases the heel is raised off the ground, and the foot rests on the balls of the toes. In extreme cases, and especially when the extensors are completely paralysed, the toes may be flexed towards the sole, and the weight is borne on the dorsum of the foot ([Fig. 146]). The patient suffers from painful corns and callosities, and from inflammation of bursæ which form over the points of pressure. When unilateral, the patient compensates for the lengthening of the limb by flexing the knee and throwing the limb outwards in walking. In severe cases, especially when both limbs are affected, the patient may be dependent on crutches.

The talus projects on the dorsum, the anterior part of its trochlear surface escapes from the tibio-fibular socket, and the calcaneus is drawn up so that it comes into contact with the bones of the leg ([Fig. 147]).

Shortening of the soft parts affects chiefly the muscles inserted into the tendo Achillis, the posterior ligament, and posterior parts of the lateral ligaments of the ankle. The fasciæ, ligaments, and muscles of the sole of the foot are also shortened. The flexors of the toes, the tibialis posterior, and the peroneus longus are shortened to a less degree.

Treatment.—Of all the deformities of the foot, pes equinus is that most easily rectified. In recent cases a great deal may be done by regular manipulations, and by the wearing of some corrective splint or apparatus between times.

In well-marked cases it is necessary to lengthen the shortened structures, and especially the tendo Achillis. When the equinus is corrected, the excessive arching of the foot (pes cavus) and the clawing of the toes usually disappear, but it may be necessary to lengthen the flexor tendons, especially that of the great toe, and also the plantar fascia.

Jones divides the tendo Achillis and the flexors of the toes subcutaneously, and maintains the dorsiflexion by excising an oval flap of skin from the front of the ankle.