s.]

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.

#Tarso-metatarsal Dislocations.#--One, several, or all of the
metatarsals may be separated from the distal row of tarsal bones--the
usual cause being a fall from a horse, the foot being fixed in the
stirrup. The bases of the metatarsal bones are displaced laterally and
towards the dorsum. The base of the second metatarsal and the first
cuneiform are sometimes fractured. Reduction by manipulation is
generally easy in dorsal dislocations, but may be difficult when the
bones are displaced laterally. This may be due to fragments of bone or
soft parts getting between the bones, and may necessitate operative
interference. In old-standing dislocations, operation is to be advised
only when locomotion is seriously interfered with.

#Dislocation of the Toes.#--The great toe may be dislocated at its
metatarso-phalangeal joint, the base of the proximal phalanx passing
towards the dorsum (Fig. 102). Diagnosis and reduction are alike easy.

[Illustration: FIG. 102.--Radiogram of Dislocation of Toes.

(Sir Montagu Cotterill's case.)]

#Inter-phalangeal# dislocations are rare and are easily reduced.

CHAPTER IX

DISEASES OF INDIVIDUAL JOINTS

THE SHOULDER-JOINT

The shoulder is seldom the seat of disease, and most affections of the
joint are met with in adults. In young subjects, infective processes
result chiefly from extension of disease from the upper epiphysial
junction of the humerus, which is partly included within the limits of
the synovial cavity. The synovial membrane, in