614 



ABNORMAL CONDITIONS OF THE SHOULDER JOINT. 



to be a point, by attention to which we may 

 be assisted in our endeavours to establish the 

 diagnostic marks between dislocation and 

 fracture, because, in fracture of the humerus, 

 we have almost invariably found, whether 

 from some overlapping of the bones, or im- 

 paction of one of the fragments into the other, 

 that some shortening of the arm exists. If 

 there be dislocation, the arm is sometimes 

 abnormally lengthened, and never shortened. 

 In the measurement of the injured limb we 

 have therefore a simple means to resort to, 

 which will no doubt assist us much in making 

 our diagnosis. 



4. We have heretofore adverted only to the 

 ordinary symptoms and anatomical characters 

 belonging to the three dislocations which the 

 head of the humerus is liable to ; but practical 

 surgeons have, however, noticed that a dis- 

 location of the head of the humerus is some- 

 times combined with a fracture of this bone. 

 In this case the fracture 'may sometimes en- 

 gage merely the tuberosities, sometimes the 

 anatomical, and sometimes the surgical neck 

 of this bone. It has been long ago noticed 

 by Thompson *, that when the head of the 

 humerus is dislocated into the axilla, the 

 greater tuberosity of this bone, which gives 

 attachment to the three posterior capsular 

 muscles, is torn off from the shaft of the hu- 

 merus, and left attached to these muscles. 

 This observation of Thompson has since been 

 repeated by others, from amongst whom we 

 have already quoted a case adduced by Sir 

 Philip Crampton, of an axillary dislocation, 

 in the dissection of which it was found that 

 the tuberosities were detached. Such a com- 

 plication with a dislocation of the humerus 

 would no doubt facilitate the reduction of the 

 dislocated bone, but its subsequent main- 

 tenance in its place would be thereby rendered 

 very difficult. 



We have reason to believe that a fracture, 

 completely detaching the greater tuberosity of 

 the humerus, may be combined with a dislo- 

 cation forwards; and in this case, although 

 the dislocation may be reduced, the head of 

 the humerus cannot be maintained in the 

 glenoid cavity. We have for some time con- 

 sidered this to be the explanation of the spe- 

 cimen contained in the Richmond Hospital 

 Museum, an account of which we find given 

 by Dr. R. Smith, and from which we abstract 

 the following: "Upon removing the soft 

 parts, the head of the bone presented itself, 

 lying partly beneath, and partly internal to 

 the coracoid process. The greater tuberosity, 

 together with a very small portion of the 

 outer part of the head of the bone, had been 

 completely separated from the shaft of the 

 .humerus. This portion of the bone occu- 

 pied the glenoid cavity, the head of the hu- 

 merus having been drawn inwards, so as to 

 project upon the inner side of the coracoid 

 process ; it was still contained within the 

 capsular ligament, which was thickened and 

 enlarged, and bone had been deposited in its 



* Medical Obs. and Enq. vol. ii. p. 349. 



tissue. A new and shallow socket had been 

 formed upon the costal surface of the neck 

 of the scapula, below the root of the coracoid 

 process, and the inner edge of the glenoid 

 cavity, the tuberosity was united to the shaft 

 only by ligament. The injury had occurred 

 many years before the death of the patient, 

 but the history of the case was not precisely 

 known." 



But fracture of the greater tuberosity may 

 also occur, as a consequence of falls on the 

 outer side of the shoulder, or otherwise, with- 

 out any dislocation following. 



Fracture of the lesser tuberosity of the 

 humerus may, we suppose, be an accident 

 likely to attend on dislocations of the head 

 of this bone, and would, we imagine, be at- 

 tended with consequences similar to those 

 which followed the laceration of the tendon 

 of the subscapularis muscle in a case of dis- 

 location on the dorsum of the scapula, no- 

 ticed by Sir A. Cooper and Mr. Key. 



Dislocation of the head of the humerus, ac- 

 companied with a fracture of the neck of the 

 humerus. Sometimes the luxation of the 

 humerus is complicated with a fracture of the 

 anatomical or surgical neck of this bone ; we 

 have then one of those rare lesions to deal 

 with, for which nature and art can do but 

 little. In such a case it is plain that the dis- 

 location has first occurred. When there is 

 both a dislocation and fracture, Sir A. Cooper 

 says, the symptoms resemble those which 

 usually accompany the dislocation into the 

 axilla, the head of the bone being there felt ; 

 but there is somewhat less of the hollow to 

 be observed below the acromion, and the del- 

 toid muscle does not seem much depressed, 

 because the broken extremity of the shaft 

 quits the head and lodges in the glenoid cavity 

 of the scapula. Upon rotating the arm, the 

 broken shaft of the bone can be perceived to 

 move under the acromion ; there is but little 

 power of motion ; and considerable pain is 

 felt not only in the shoulder, but in the arm 

 and hand. The head of the os humeri can 

 be felt when the arm is raised, and the sur- 

 geon's fingers are introduced into the axilla ; 

 but when the arm is rotated at the elbow, the 

 head of the bone remains entirely unmoved, 

 or very little obedient to the motions of the 

 elbow. In some cases, but not always, a dis- 

 tinct crepitus can be perceived. 



The broken end of the os humeri is drawn 

 somewhat forwards, but is easily pushed into 

 the glenoid cavity, from which, unless it be 

 supported, it is again drawn by the pecto- 

 ralis and coraco-brachialis muscles. 



The arm, measured from the acromion to 

 the elbow, is shorter than the other.* 



As this accident is produced by great vio- 

 lence, the parts are much obscured by the 

 effusion of blood, and by the inflammation 

 which speedily follows ; but, for the first three 

 hours, the muscles are so lax, that but for the 

 pain it occasions, considerable motions of the 

 limb might be produced. 



* Smith on Fractures. 



