Dislocation means the displacement of the articular ends of bones, without concomitant fracture. This accident happens most frequently in the hip, elbow, shoulder, knee, hock, and toe joints.

Symptoms

The symptoms are, - that the joint is altered in form as compared with the corresponding joint of the opposite side - there is a depression or a prominence where there should be neither, and the limb is either lengthened or shortened. The joint is fixed and its natural movements are circumscribed; neither the dog nor his doctor can move the limb with its natural facility and to its natural extent. This fixedness of position, and the absence of crackling are sufficient to distinguish dislocation from fracture. There is another distinction of great value: if a broken bone be put into its proper shape by adjusting its broken ends, the deformity will presently return when the bone is left to itself; whereas, a dislocated bone put into its natural place remains there and the distortion is removed.

Sometimes there may be both dislocation and fracture of the same bone, and then the difficulty of cure is increased.

In dislocation of the hip-joint, the head of the femur (or thigh bone) is carried away from the socket in three different directions, viz., upwards, backwards, or forwards; or upwards and backwards at the same time. The exact dislocation may perhaps be made out by ascertaining the exact position of the head of the bone by the unnatural prominence which it occasions. In this, and indeed in all other cases, it is necessary to determine the direction of the dislocated bone, because the mode of its reduction is varied accordingly.

The stifle-joint may be dislocated inwards, or outwards, - more frequently the former.

The lower jaw is sometimes, but rarely, dislocated downwards. The elbow-joint is more frequently dislocated inwards than outwards, and there is usually fracture also.

Treatment

Dislocations are reduced by those means which bring the head of the bone into such a position that the muscles fixed to it can drag it into its socket. The socket is firmly held by an assistant and kept fixed, whilst the operator pulls the limb gently and steadily till the muscular resistance is counteracted, and the bone slips into its proper place. The joint should then be kept in perfect rest, to prevent inflammation. Dislocations should be reduced as speedily as possible.

It is plain that each dislocation requires a different mode of reduction as regards the direction in which the extending power should be applied, the joint affected, and the relative position of the head of the bone to its socket. It is impossible to give full directions for every case without a long lecture upon, and a demonstration of, each joint. The best plan is to call in a veterinary surgeon, or in his absence a human surgeon, who would no doubt willingly render his services and apply his knowledge of the treatment of man's dislocations to those of the dog.