Changes of the nature of chronic arthritis are liable to occur in and around the joint in old and rheumatic subjects; and atrophy or paralysis of muscles may follow, if their nerves are implicated.

Old-standing Dislocation.—It is impossible to lay down any time-limit for attempting reduction in old-standing dislocations of the hip. Manipulation may succeed in cases of some months' standing, and may fail when the bone has been out only a few weeks. In certain cases, even after reduction has been effected, there is a marked tendency to re-displacement. In any case, the attempt does good by breaking down adhesions, provided no undue force is employed such as may damage the sciatic nerve or vessels, or fracture the neck of the femur, and success may attend on a second or even a third attempt at intervals of from three to five days. If manipulation fails, and if the deformity is great and the usefulness of the limb seriously impaired, an attempt may be made to effect reduction by operation; the operation, however, is one of considerable difficulty, and in the event of failure the head of the bone should be excised. If the head has formed a new socket for itself and there is a fairly useful joint, the condition should be left alone.

Congenital dislocation of the hip is described with Deformities of the Extremities.

Sprain of the hip is comparatively rare. It results from milder degrees of the same forms of violence as produce dislocation. The ligaments are stretched or partly torn, and there is effusion of fluid into the joint. Pressure over the joint elicits tenderness; and the limb assumes the position of slight flexion, abduction, and lateral rotation, but there is no alteration in length. Such injuries, unless carefully treated by massage and movement from the outset, are apt to be followed by the formation of adhesions, resulting in stiffness of the joint.

Contusion in this region, on the other hand, is not uncommon. It is produced by a fall on the trochanter, and gives rise to symptoms which simulate to some extent those of fracture of the neck. The limb lies in the position of slight flexion, but the bony points retain their normal relationship to one another, and there is no shortening. The swelling and tenderness often prevent a thorough examination being made, and when any doubt remains as to the diagnosis, the patient should be kept in bed till the doubt is cleared up by the use of the X-rays. If the bone has been broken, this will reveal itself in the course of a few days by the occurrence of shortening and other evidence of fracture.

In elderly patients, contusion of the hip may be followed by changes in the joint of the nature of arthritis deformans; and it has been stated, although proof is wanting, that absorption of the neck of the femur sometimes occurs. These injuries are treated by rest in bed, massage, and the other measures already described as applicable to sprains and contusions.

Fracture of the Shaft of the Femur

This group includes all fractures between that immediately below the lesser trochanter and the supra-condylar fracture.