DISLOCATION consists in the displacement of one bone from another with which it forms a joint (put out of joint being the popular expression). Dislocations are generally the result of sudden accident, but may be the result of disease, or may be congenital. The displacement may be partial or complete; and surgeons classify their cases into simple dislocations, when the skin remains unbroken, and compound, when there is a wound by which the external air may communicate with the joint. Occasionally, in addition to the dislocation, there are fractures of the bones, or lacerations of important blood-vessels in the neighborhood; it is then termed a complicated dislocation. Dislo cation is a rare accident in infancy and old age, because in the former the joint-ends of the bones are very flexible, and yield to violence; while the aged skeleton is so rigid that the brittle bones fracture under force that would drive younger and firmer ones out of their sockets. Dislocations are most frequent between the ages of thirty and sixty. Persons with weak muscles, and lax, long ligaments, or those in whom the latter have been softened by inflammation of the joint, are predisposed to dislocation. The joints most frequently displaced are the shoulder and the elbow.
General symptoms of a dislocation.—After a blow, fall, or violent muscular exertion, a limb is found to be immovable at the injured joint, there is great pain, and the shape of the part is changed; but soon swelling ensues, and every distinctive mark about it is obscured. If left alone, or merely treated as an inflamed joint, the swelling gradu ally subsides; but the immobility continues, the limb is crippled for months or years, when at last nature forms a new socket for the end of the bone, and some amount of useful motion is restored. The proper shape of the part is never restored, but remains an eyesore to the patient, and a disgrace to the surgeon.
The general treatment of dislocations consists in their reduction, or pulling the dis placed bone back into its place. Its return is opposed by the muscles attached to it, which are stimulated to contraction by the pain of the operation, which requires, of course, a good deal of force to be employed. It is desirable to remove this spasm of the muscles, which is the great obstacle to the reduction of a dislocation; and in former days, bleeding from the arm, emetics, the warm bath, etc., were generally made use of; nowadays, cldoroform or ether attains the same ends, and renders the treatment of dis locations much more simple and humane than before the introduction of ansestheties.
When the surgeon is about to reduce a dislocation requiring any degree of force, he fastens the part of the limb above the displaced bone or the trunk, so as to afford him counter-extension; he then pulls on the limb either with his hands, or With a band age or handkerchief attached to it. The best way of fastening this is to roll a bandage,
wetted, to prevent slipping, round the limb, and then taking the thing with which he wishes to extend in both hands, lie casts it into two loops, forming what is called a clocc-hiteh, and then slips the double noose up the limb till it rests on the wet bandage previously applied. In old-standing cases, the hands grow weary before the extension has been kept up sufficiently long, so it is well to adapt pulleys to draw upon the clove hitch, as with them the traction can be regulated as the surgeon desires. Sudden, for cible pulling is useless and hurtful, the object being merely to tire out the muscles which resist dmattempts at reduction; when they are exhausted, the bone will generally slip back into its place with an audible snap.
A class of shrewd individuals, called "bone-setters," frequently derive profit from some conditions of joints which resemble dislocations. Chronic rheumatic inflamma tion is occasionally known to fix itself by an accident on some particular joint, especially the shoulder or hip, and may so change the surfaces of the bone-ends that they are spontaneously dislocated; the empiric, naturally antagonistic to the regular practitioner, tells the patient that whin he met with the accident the dislocation occurred. but that his doctor overlooked it. Again. many prisons who have injured their joints do not submit to having them moved about after the first inflammation has subsided. The bone setter gives a forcible bend to the limb, which breaks up the adhesions; and because he has done roughly what the doctor would have done equally well gently, the patient praises him, while he blames the one who guided his joint in safety through the first effects of the accident.
Whenever a dislocation occurs, the nearest medical man should be summoned, even should the mere displacement be rectified at once, because no such accident can occur without some tearing of the soft parts, and it will depend on the after-treatment whether the joint will ever become useful again or not. It must also be remembered, that the sooner a dislocation is reduced, the easier is the reduction. Since the introduction of anwsthesia, however, and the subcutaneous division of tissues, many ancient cases may be improved, and many crippled limbs restored to usefulness.