In rare cases the rhomboid ligament is torn, and the end of the clavicle passes _upwards_, and rests in the episternal notch behind the sterno-mastoid muscle. The bone may be retained in position by keeping the shoulders braced back by a figure-of-eight bandage, or by padded handkerchiefs, and making pressure over the displaced end of the bone with a pad. The forearm is supported by a sling, and the arm fixed to the side. Massage is employed from the first, and the patient is allowed to move the arm by the end of a week. Imperfect reduction interferes so little with the functions of the limb that operative measures are seldom required except for æsthetic reasons. Dislocation of #both ends# of the clavicle has occasionally occurred from a severe crush. The ultimate result has been satisfactory, as one or other end has always healed in normal position, and the function of the arm has thus been maintained. DISLOCATION OF THE SHOULDER The shoulder is more frequently dislocated than all the other joints in the body taken together. This is explained by its exposed position, the wide range of movement of which it is capable, the length of the lever afforded by the humerus, and the anatomical construction of the joint--the large, round humeral head imperfectly fitting the small and shallow glenoid cavity, and the ligaments being comparatively lax and thin. The capsule of the joint is materially strengthened in its upper and back parts by the tendons of the supra- and infra-spinatus and teres minor muscles; while it is weakest below and in front, between the subscapularis and teres major tendons. It is here that it most frequently gives way and allows of the escape of the head of the bone. The determining factor is probably that when the arm is abducted the neck of the humerus comes in contact with the tip of the acromion, and further abduction forces the head against the lower, weak portion of the capsule, which gives way. The violence is usually transmitted from the hand or elbow, less frequently from the lateral aspect of the shoulder, the limb being usually abducted and the muscles relaxed and taken unawares. The head of the humerus, thus brought to bear on the weakest part of the capsule, ruptures it and passes out through the rent. Dislocation is readily produced in an unconscious person--as, for example, in conducting artificial respiration in a patient suffering from opium poisoning, the arms being hyper-abducted to exert traction on the chest.