When the foot is dorsiflexed at the moment of injury the displacement is _backward_, but this is rare, as is also _dislocation to one or other side_, and _dislocation by rotation_, in which the talus is rotated in its socket. In all these injuries the body of the talus loses its normal relationship with the malleoli. An attempt should be made to reduce the dislocation under anæsthesia, the limb being placed in the same position as for reduction of dislocation of the ankle. While traction is made upon the foot, an assistant presses directly on the displaced bone and endeavours to manipulate it into position. In incomplete dislocations this usually succeeds, but it not infrequently fails in those which are complete, and under these circumstances it may be necessary to chisel through the lateral malleolus to admit of reduction, or to excise the talus. In most cases of compound dislocation also, this bone should be removed. #Sub-taloid Dislocation.#--In this dislocation, which results from the same kinds of violence as the last, the talus retains its position in the tibio-fibular socket, and the calcaneus and navicular, with the rest of the foot, are carried away from it. The body of the talus, therefore, maintains its normal relationship with the malleoli--a point of importance in the differential diagnosis between this injury and dislocation of the talus. The displacement is usually incomplete, and the foot may either pass backward and medially, or backward and laterally. When the foot passes _backward and medially_, the head of the talus projects on the outer part of the dorsum, resting on the cuboid. The dorsum of the foot is shortened, the heel lengthened, the toes adducted, and the medial border of the foot raised. The lateral malleolus is unduly prominent, and reaches nearly to the sole. [Illustration: FIG. 101.--Radiogram of Fracture-Dislocation of Talus.] In the _backward and lateral_ variety, the medial malleolus and head of the talus project unduly towards the medial side of the foot, which is abducted and everted. In neither variety is there any mechanical obstacle to movement at the ankle-joint. The _treatment_ is carried out on the same lines as for dislocation of the talus, reduction being effected without difficulty in most cases. If this fails, as it occasionally does, it may be necessary to excise the talus. #Mid-tarsal or transverse tarsal dislocation#--that is, at the talo-navicular and calcaneo-cuboid articulations--is extremely rare. The distal segment of the foot is usually displaced towards the sole; the foot is foreshortened, the malleoli raised from the sole, the arch of the foot is lost, and the first row of tarsal bones projects on the dorsum. The treatment consists in reducing the displacement by manipulation, after which massage and movement are employed.