ABNORMAL CONDITIONS OF THE SHOULDER JOINT. 



615 



In one case detailed by Sir A. Cooper, the 

 tubercles were broken off with the head of 

 the bone, and the fractured extremity of the 

 neck of the os humeri was placed in the 

 glenoid cavity of the scapula. In another 

 case, the fracture was intra-capsular, and the 

 head of the bone was at the same time dis- 

 located forwards, under the pectoral muscle, 

 and placed at the inner side of the coracoid 

 process. 



Delpech * gives the history of a case of 

 fracture of the anatomical neck of the hu- 

 merus, combined with a dislocation. The 

 case was remarkable, and differed from all 

 the others recorded, in being an example of 

 that rare form of dislocation, where the bone 

 is thrown on the dorsum of the scapula. The 

 history of the case is accompanied with an 

 engraving. 



With regard to the case of dislocation into 

 the axilla, complicated with fracture, Sir A. 

 Cooper says, " I would observe that in this 

 case the fall and depression of the shoulder 

 is less striking than in the case of simple ax- 

 illary dislocation, as the shaft of the bone 

 fills up the glenoid cavity ; also, that in the 

 case complicated with fracture, the head of 

 the bone can still be distinctly felt in the axilla, 

 and that as it does not move when the os 

 humeri is rotated from the elbow, this be- 

 comes the principal diagnostic mark. 



" That a grating sensation can generally be 

 felt, and sometimes a very distinct crepitus, 

 especially if the elbow be raised outwards 

 during the rotation of the arm. 



" That the upper extremity of the shaft of 

 the humerus can be felt advancing to the 

 coracoid process ; but that it is easily re- 

 turned into the glenoid cavity, and that it 

 there rotates with the arm, but easily again 

 slips forward. 



" That the accident which produces it is 

 much more severe than that by which simple 

 dislocation into the axilla is produced ; and 

 there is, therefore, more contusion, more 

 swelling, and more pain." 



Muscles. If in some cases the tuberosities 

 of the humerus are broken off and remain 

 connected with the muscles when the head 

 of the humerus is dislocated, in others, we 

 may be prepared to expect that in the dis- 

 section of cases of dislocation, the capsular 

 and other muscles will be found lacerated. If, 

 as has been stated, the supra-spinatus be the 

 muscle which is most put on the stretch when 

 the head of the humerus is dislocated down- 

 wards, we need not be surprised to learn that 

 this muscle is very frequently found to have 

 been ruptured, or to have torn away a frag- 

 ment of bone from the head of the humerus. 



In the dislocation on the dorsum of the 

 scapula, the dissection of which is detailed in 

 Sir A. Cooper's work, we find the following 

 observations made by Mr. Key, with reference 

 to a very peculiar phenomenon noticed in 

 that case : namely, " that, during the patient's 

 life-time it was thought probable that a portion 



* Clinique Chirurgicale, Paris, torn. i. p._234. 



of the glenoid cavity had been broken off, or 

 a piece of the head of the os humeri, or 

 perhaps the smaller tubercle ; and that any 

 of these injuries would account for the head 

 of the bone not remaining in its natural 

 cavity when reduced ; but the inspection post- 

 mortem proved that the cause of this symptom 

 was the laceration of the tendon of the sub- 

 scapularis muscle, which was found to adhere 

 to the edge of the glenoid cavity, and much 

 thickened and altered in its character from its 

 laceration, and very imperfect and irregular 

 union." 



The tendon of the long head of the biceps 

 is sometimes altered, as to its direction, in 

 cases of complete dislocation, and adhesions 

 between it and the contiguous parts occur ; 

 but there are very few cases recorded, or to 

 be found in museums, which prove that in 

 true dislocation from accident, the tendon 

 was found ruptured. In this respect, the 

 effects of accident and disease on this tendon 

 are strongly contrasted ; for, as the result of 

 disease, the tendon, so far as its articular por- 

 tion is concerned, is very generally removed 

 altogether. 



Besides lesions affecting the bones, mus- 

 cles, and tendons, injuries of other tissues 

 may be found occasionally to accompany or 

 succeed to dislocations of the shoulder. 



A dislocation of the head of the humerus 

 may be accompanied with an cedematous 

 swelling of the arm and forearm ; with a pa- 

 ralysis of the dislocated extremity, or with a 

 laceration of the axillary artery, and a dif- 

 fused aneurism ; it is said also that occasion- 

 ally an emphysematous swelling of the shoul- 

 der has followed the reduction of the dis- 

 location ; and on other occasions, that the 

 articular structures have been attacked with 

 very severe inflammation. For example, as 

 to this last : Mr. Hunter gives an account of 

 a case of dislocation of the shoulder-joint, 

 which he dissected three weeks after its re- 

 duction, from which, if we could be influenced 

 by one case, we might infer that inflammation, 

 though latent, may sometimes be the conse- 

 quence of a dislocation of the head of the 

 humerus. Mr. Hunter's observation is as 

 follows : " What was very remarkable, and 

 what I did not expect, there was a good deal 

 of pus in the joint." * 



Partial or general paralysis of the muscles 

 of the arm has also been observed as a con- 

 sequence of a dislocation of the head of the 

 humerus, particularly when either the circum- 

 flex nerve alone, which is that most usually 

 injured, or all the nerves of the brachial 

 plexus have been violently contused, or greatly 

 stretched ; or even torn across either at the 

 time of the accident, or by the violence of the 

 means used to restore the luxated humerus, 

 when the dislocation has been left long un- 

 reduced. Flaubert, of Rouen, speaks of an 

 emphysema of the chest succeeding his efforts 

 to reduce an old luxation of the humerus ; 



* Pathological Catalogue of Museum of R. C. 

 Surgeons, England, vol, ii. p. 20. No. 868. 

 R R 4 



