fragment may be displaced backward with luxation of the head of the radius. If complications are present, they may render the prognosis unfavorable; otherwise passive and active mobility should be restored after reduction. Treatment.-The method of reduction is shown in figures 83-86. As in every hinge-joint, reduction requires more than a simple pull, no matter how strong it may be. It must be effected without using force, as if the surgeon. were toying with the joint, so to speak; anesthesia is usually required. The forearm in supination is first overextended so as to dislodge the coronoid process from the supratrochlear fossa. Moderate traction then draws the forearm forward, while the other hand seizes the injured elbow and controls the position of the parts; or the thumb may be braced against the lower end of the humerus and the other fingers, especially the third and fourth, against the head of the radius and olecranon behind, and by direct pressure assist in the act of reduction. Flexion of the arm is now found to proceed without any obstacle; the dislocation disappears and the normal contact between the articular surfaces is restored. After-treatment according to general principles; fixation of the arm for two days, the dressing being changed at short intervals and massage administered; later passive movements. (b) Lateral Dislocation of the Forearm (Plate 39).— Lateral dislocations at the elbow-joint are not rare; outward dislocation is more frequent than inward, and is usually combined with fracture of the internal epicondyle. This fracture is the direct result of the contusion sustained during the fall which produces the dislocation; or it may be a sprain fracture due to the pull of the lateral ligament. It always affects the condyle furthest removed from the forearm; hence in outward dislocation the internal condyle is fractured, and, inversely, in inward dislocation the external condyle. The forearm and humerus are still in contact, but the articulation is abnormal. Thus, in outward dislocation the ulna articulates with the trochlea and the head of the radius projects beyond the joint. As a rule, the forearm is at the same time displaced backward, producing the combination of lateral and posterior dislocation (luratio posterior externa or postero-lateralis). While backward dislocation may occur without destroying the integrity of the lateral ligaments (although the internal ligament is, as a matter of fact, generally torn), lateral luxation is usually associated with great destruction of ligaments and fracture of the epicondyle. This variety is also described as an incomplete dislocation, in contradistinction to complete dislocation of the bones in which no portion of one articular surface remains in contact with any portion of the other. A lateral dislocation can only be produced by exaggerated movements of abduction or adduction. The capsule is greatly distended and sometimes presents a lateral tear. The symptoms of a complete lateral dislocation to the outside, for instance, are unmistakable and need no description. In incomplete outward dislocation (Plate 39) the prominence formed by the head of the radius is distinctly seen and felt. To the inner side, part of the trochlea can be seized between the fingers, and the separated internal epicondyle may be felt or appears as a marked prominence. By gently moving the parts under anesthesia a clear conception of the conditions is at once obtained. [Recently Eversmann 1 has reported two interesting observations of the outward lateral dislocation of the elbow-joint. In both cases the fragmented internal epicondyle had become displaced into the joint, and after the reduction of the dislocation, the interposition of this fragment produced symptoms and restricted function. Both 1 Deut. Zeitschr. f. Chir., 1901, Bd. LX, p. 528. were subjected to operation with good results. The Röntgen photographs of these two cases are quite clear. This possibility should always be borne in mind in this rare form of dislocation.-ED.] Incomplete inward luxation (luxatio postero-medialis) presents the external epicondyle in marked anterior displacement, or completely separated from the bone. The ulna projects beyond the inner line of the arm and its articular surface can be felt; the head of the radius articulates with the trochlea; and part of the capitellum humeri may be palpated. The prognosis depends on the complications. Treatment.-Reduction is effected under anesthesia with the least amount of injury to the patient by overextending the arm under direct lateral pressure with the other hand, followed by traction and flexion. If something is found interposed between the articulating surfaces, exaggerated lateral movements, overextension with abduction, etc., are sometimes successful. If efforts at reduction fail, early removal of the obstacle through an incision is indicated, preferably by means of a bilateral arthrotomy. Excellent results may be obtained by this procedure. (c) Forward Dislocation of the Forearm (Luxatio antibrachii anterior).-This is a very rare injury. It was formerly said that it never occurred without simultaneous fracture of the olecranon. It may be produced by a fall or blow on the olecranon while the arm is in extreme flexion. Symptoms. The prominence of the olecranon is missed from its normal position, and the outline of the lower end of the humerus can be felt on the posterior side of the bone. If the outer side of the olecranon is still in contact with the trochlea, the arm being almost in extension, an incomplete luxation exists. In complete dislocation the tip of the olecranon is found in front of the articulating surface of the lower end of the humerus, and the arm is bent at an acute angle. Reduction is effected by direct pressure, with moderate extension. |