70 



ABNORMAL CONDITION 

 Fig. 41. 



Luxation of both bonei lackwarfa. 



us for examination more or less flexed, this 

 process is placed much behind and somewhat 

 below the plane of the condyles of the humerus. 

 The tendon of the triceps carried back with the 

 olecranon stands out in relief, as the tendo 

 Achillis does from the malleoli. This part of 

 the triceps thus standing out can be seized 

 through the integuments by the fingers, and we 

 perceive in front an interval between it and the 

 back part of the humerus. Anteriorly, in the 

 fold of the. arm, through the thickness of the 

 soft parts, we can feel a hard tumour, situated 

 obliquely from without inwards and back- 

 wards, formed by the lower articular extremity 

 of the humerus. The rounded head of the 

 radius can be seen prominent below the exter- 

 nal condyle, and we can occasionally even sink 

 the end of the thumb into the hollow of its 

 cup-like extremity, and if now a movement of 

 pronation and supination be communicated to 

 it, the nature of the case becomes very evi- 

 dent. 



The patient himself feels the arm powerless, 

 and we find we can communicate to it but 

 little motion. When we make the attempt to 

 rotate or flex the arm on the fore-arm, we find 

 our efforts resisted, and that we give the patient 

 pain; a little extension of the elbow-joint is 



OF THK ELBOW-JOINT. 



allowed ; and we have invariably found that a 

 lateral movement of abduction and adduction 

 could be given to the fore-arm, motions this 

 joint does not enjoy in the natural slate, but 

 which we can account for being now permitted, 

 when we recollect the complete laceration the 

 lateral ligaments must suffer in this injury. 



The transverse fracture of the lower extremity 

 of the humerus, or a forcible separation of its 

 lower epiphysis, are accidents most liable to 

 be confounded with luxation of both bones 

 backwards; but although the elbow projects 

 much backwards, and there is a marked 

 prominence in front, still the relative position 

 of the condyles of the humerus and the olecra- 

 non process is not altered in the fracture, as they 

 have already been described to be, in the lux- 

 ation. Add to this, that in the fracture the sur- 

 geon can flex the patient's fore-arm on his arm, 

 a movement which, in the luxation, the patient 

 can neither himself fully perform, nor can it be 

 communicated. 



In the case of the transverse fracture also, 

 notwithstanding the apparent similitude at first 

 with the luxation, when a steady extension is 

 made by pulling the hand forwards, while the 

 arm is fixed, all the marks of luxation disap- 

 pear, to return again very shortly, when the 

 extending force is relaxed. In fracture, too, a 

 characteristic crepitus may be felt just above 

 the elbow-joint, by rotating the fore-arm on the 

 humerus. It is very true that, in some cases 

 of luxation, the dislocated bones are very rea- 

 dily restored to their place, and on the other 

 hand, that a transverse fracture of the humerus 

 may, after it is reduced, remain so for a little 

 time, and thus we may perhaps account for the 

 fact, that these accidents have been confounded 

 with each other, and the mistake is a serious 

 one. To guard against error in our diagnosis, 

 it would be well, after the bones have been re- 

 duced, to try the experiment of pushing the 

 fore-arm backwards, while the arm is steadily 

 pressed forwards ; if the accident has been a 

 luxation, no change occurs, but if there has 

 been a transverse fracture of the humerus, or 

 of the coronoid process of the ulna, all appear- 

 ances which erroneously induced a suspicion 

 that the accident was one of luxation, are re- 

 newed, but not so the error of attributing these 

 appearances to a luxation, for now the exist- 

 ence of a fracture can no longer be doubted. 

 Lastly, after the bones, in a case of luxation, 

 are apparently restored, it will be prudent to 

 examine the head of the radius, and it will be 

 riht to be satisfied that this bone has also been 

 replaced as well as the ulna, for, in the luxa- 

 tion of both bones backwards, the connexion of 

 the radius with the ulna by means of the coronary 

 and oblique ligaments, may have suffered, and 

 under such circumstances, if care be not taken, 

 the restoration of the radius to the lesser sig- 

 moid cavity of the ulna and capitulum of the 

 humerus may have been forgotten, as we have 

 known to have happened in one instance. 



When the luxation of both bones backwards 

 is simple, and by mistake or neglect has been 

 left unreduced, the case soon becomes irreme- 



