[42] The shoulder is liable to numerous injuries that produce disability. Pain in some of these conditions may be almost constant and spread upward to the neck and be aggravated by even passive motion. Loss of power varies from moderate paresis to complete paralysis. When the circumflex nerve is especially involved it is the deltoid which shows the effects. More severe injuries may involve the muscles of the arm and the forearm. Muscle atrophy may be greater than can ordinarily be accounted for by mere disease. In rheumatic patients a dry synovitis may be added to the other complications. Most of these features are due to traumatic neuritis. When aggravated they may result from rupture of nerves or cicatricial formations around them. The best treatment consists of immobilization for three or four weeks to favor nerve repair, counterirritation, especially with the flying cautery, over the roots of the branchial plexus, with massage, electricity, and even deep injections of strychnine to stimulate the paralyzed muscles. When paralysis is persistent and scar tissue seems to press upon nerves, exposure of the plexus and freeing its branches from all source of pressure will be necessary.
DISLOCATIONS OF THE ELBOW.
The irregularities of the elbow-joint have permitted a complicated dovetailing of its component parts which would seem to make dislocations almost impossible without fracture. Nevertheless, and especially in the tender years of childhood, both bones may be dislocated in either direction, or either bone of the forearm alone in any direction save toward the other. Diagnosis will be greatly aided by observance of the anatomical facts stated in the section on fractures of the elbow-joint and by an estimate of the relative positions occupied by these bony landmarks. When, however, intense swelling prevents this then we should either wait for its subsidence or depend upon a skiagram.
The most common dislocation is that of both bones backward, one of the possible consequences of a fall upon the extended arm and palm of the hand. The coronoid process may rest beneath the joint end of the humerus, making the dislocation incomplete, or back of it, making it complete. If the coronoid process has been broken off the dislocation can be made and reduced as often as desired. The fan-shaped lateral ligaments are always more or less lacerated. The arm will be partially bent and there will be prominent deformity upon the posterior aspect of the joint while the axes respectively of the arm and the forearm will be somewhat disturbed. Usually the lower end of the humerus can be felt in front of the normal situation of the elbow-joint ([Figs. 350], [351] and [352]).
Reduction is more or less easily accomplished by traction with an easy movement, by which the upper end of the forearm shall be directed toward its proper position.
Lateral displacements result also from falls in extreme positions. Lateral dislocations are rare and the result of violence, and may compel amputation. In these cases the lateral diameter of the joint is markedly increased, while the normal relation of the condyles to the olecranon is greatly altered. In these cases movement is painful and limited.
Fig. 350
Backward dislocation of both bones. (Lejars.)
Fig. 351