620 



ABNORMAL CONDITIONS OF THE SHOULDER JOINT. 



Case. A woman, named Judith Doyle, 

 died upon the 8th of February, 1839 : she had 

 been a patient for fifteen 3 ears in the lunatic 

 department of the House of Industry ; was 

 subject to severe epileptic convulsions, which 

 were the cause of her death. While making 

 the examination of the brain, the unusual ap- 

 pearance which the left shoulder joint presented 

 accidentally attracted the author's attention. 

 The head of the humerus appeared to have 

 been dislocated on the dorsum of the scapula. 

 Finding that the opposite shoulder presented 

 precisely similar appearances, he had no 

 hesitation in expressing his opinion that the 

 case was one of double congenital luxation of 

 the head of the humerus backwards. 



The two shoulders resembled each other so 

 perfectly, not only in their external conform- 

 ation, but likewise in their anatomical cha- 

 racters, that the description of one will be 

 sufficient. 



The coracoid process, owing to the removal 

 of the head of the humerus from its vicinity, 

 formed a most remarkable projection, and the 

 subject being emaciated, the coraco-brachialis 



Fig. 443. 



Congenital malformation of the left humerus' 



and the short head of the biceps could be seen 

 passing very obliquely downwards and out- 

 wards, and the anterior margin of the coraco- 

 acromial ligament stood out in strong relief. 

 The acromion process was unusually promi- 

 nent, although it did not project as much as 

 in any of the accidental dislocations of the 

 shoulder. The glenoid cavity could not be 

 felt, although the head of the humerus was so 

 far removed from its natural position. The 

 shoulder appeared higher than natural, and 

 was flattened anteriorly; but posteriorly a 

 round, solid tumour plainly indicated the 

 situation of the head of the bone placed on 

 the dorsal surface of the scapula, immediately 

 below the spine and posterior angle of the 

 acronaion. The head of the bone thus dis- 

 placed could be seen and felt to accompany 

 jail the movements given to the shaft of the 

 humerus. The transverse diameter of the 



shoulder was much greater than natural, the 

 distance between the coracoid process and the 

 external surface of the head of the humerus 

 being three inches and a half; the arm was 

 directed obliquely downwards and inwards ; 

 the elbow was in contact with the side, and 

 the hand and fore-arm in a state of prona- 

 tion. Upon removing the muscles and ex- 

 posing the interior of the joint, I found that 

 there was no trace of a glenoid cavity in the 

 natural situation ; but upon the posterior 

 surface of the neck of the scapula there was 

 a well-formed socket, which received the 

 head of the humerus. It was an inch and 

 three quarters in length, and one inch in 

 breadth ; it was a little broader above than 

 below, and its summit was less than a quarter 

 of an inch from the under surface of the acro- 

 mion process. It was directed outwards and 

 forwards, was covered with cartilage, and sur- 

 rounded by a perfect glenoid ligament. The 

 tendon of the biceps muscle arose from the 

 most internal part of its superior extremity, 

 from whence it passed downwards and out- 

 wards very obliquely, in order to reach the 

 bicipital groove of the humerus. 



The axillary margin of the scapula, if pro- 

 longed upwards, would have passed nearly 

 altogether internal to the abnormal socket. 

 The surfaces of the acromion process had 

 not their normal aspects, but looked directly 

 upwards and downwards, being on the same 

 continuous plane with the surfaces of the 

 spine of the scapula that contribute to form 

 supra- and infra-spinatus fossa ; a circumstance 

 in itself sufficiently showing that the mal- 

 formation was congenital, and not altogether 

 limited to the shoulder joint itself. The 

 capsular ligament was perfect; the scapula was 

 smaller than natural, and its muscles badly 

 developed. The head of the humerus was of 

 an oval form on the right side, somewhat 

 broader above than below; its anterior half 

 was in contact with the glenoid cavity : this 

 portion was covered with cartilage, the re- 

 maining half being rough and scabrous, and 

 destitute of articular cartilage. The greater 

 tubercle was normal as to form, but the lesser 

 was elongated for the extent of one inch, and 

 curved upwards, forming a concavity on its 

 upper surface to receive the tendon of the 

 biceps ; on the left side, the head of the 

 humerus presented almost similar appear- 

 ances. The hypertrophy of the lesser tube- 

 rosity, Mr. Smith observes, appears to have 

 been the result of a process established to 

 counteract the danger to which the very 

 oblique course of the tendon, with regard to 

 the muscular fibres, exposed it. 



The history of this case, so far as the mo- 

 tions which the head of the humerus was ca- 

 pable of performing, is not known ; but we may 

 conclude from the post-mortem examination, 

 that there was here a complete congenital 

 dislocation on the dorsum of the scapula. 

 A well-formed socket existed on the dorsum 

 of the scapula, upon which the head of the 

 humerus was permanently lodged ; it did 

 not shift its position during the motions of 



