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Show tsrs ..--.-.-4w,..a-v:,-.» <; . 130 rnac'wne or Inn names. FRACTURE or THE RADIUS. tural state of the joint, the olecranon cheeks into the hollow of the humerus so as to stop the motion at its due limit, but that check being now done away, the fore arm may be bent bacl: unnaturally, and the ligaments of the joint strained. In the second place, it must be observed, that if the joint broken part of the radius; D, the lower portion: now by the falling of the palm C, prone, the portion D, turning in the circle A, B, is separated from the upper portion of the bone, and the tearing of the cellular substance, or the bearing of the sharp bone against the parts, is the cause of the pain. 131 r , be not enough extended when the bone is set, callus or new bone will be formed betwixt the ulna and the process which has been broken off, and a kind of anchylosis is the conse- quence ;‘for the olecranon process projecting now too far, will strike into the hollow of the humerus, before the fore arm can be fully extended. 5445M mum , See plan plate IV. fie. 4:. A, is the humerus ; B, the ulna; C, the olecranon, broken off ; D, the hollow of the humerus, into which the olecranon should sink, when the arm is fully l l; extended. But it is evident, that if the dotted line betwixt B, and C, be filled with new bone, there must be a stiffness It will be manifest, at the same time, that, if the bone be allowed to remain in this position, a great, irregular callus must be formed betwixt the ends of the bones ; and that, when they are thus fixed together, the hand will be no longer capable of snpination. In setting the radius when fractured, we have to apply the splints thus : one along the inside and the other on the out- in the joint, of the nature of anchylosis. FRACTURE OF THE RADIUS. THE fracture of the radius may be the consequence of a direct blow on the fore arm ; or of a person's falling and endeavouring to save himself, by extending the hand; for the carpus being articulated with the radius, the whole shock and weight of the body falls on this bone. The nature of the injury will be ascertained by the usual symptoms of fracture : and, besides, it will be found that the hand falls prone, with much pain, because the weight of the hand bears so that the carpal bones and lower head of the radius turn on the small head of the ulna, while the upper side of the fore arm : The one on the inside should be long enough to reach to the palm, that it may prevent pronation. it is important to observe that if a splint be laid along the ulnar edge of the fore arm, and be made to reach to the palm; or if the arm and hand be laid carelessly in a sling, the following bad consequence results : the ulnar edge of the palm is pressed up, the head of the radius receives that pressure, and the broken ends of the bone are pressed down upon the ulna, as is expressed in this sketch. rum" W]- o‘w-ag.,g.,« f.--a~'.. p... , . part of the radius, not following the lower in its rotation, the broken ends are separated, and the surrounding parts injured. The patient therefore comes to you, holding the palm of the injured arm with his other hand, to prevent the motion either of pronation or supination, but especially the former. The effect of pronation will be understood by looking to the annexed sketch of the bones of the fore arm. A, is the upper 4/. A, is a splint, on which the arm and hand rest. Now it is evrdent that, when the ulnar edge of the hand is thus raised, ' kW "were \ wow M0955 11- |