ABNORMAL CONDITIONS OF THE SHOULDER JOINT. 



599 



arthritis exist in this shoulder joint, but also 

 that the acroniio-clavicular articulation in the 

 same specimen is enlarged externally; and 

 that, on examining it internally, it presents 

 undoubted traces of this chronic rheumatic 

 disease. Upon the whole, therefore, we feel 

 convinced that this specimen produced by 

 Professor Hargrave as an example of a case 

 of partial luxation inwards, the result of acci- 

 dent, does not really afford any proof that exter- 

 nal injury was the cause of the partial luxation. 



In thus differing from Professor Hargruve, 

 we would make the same remarks which we 

 have already made in allusi< n to Sir A. Coo- 

 per's case, at page 591. of this article. The pro- 

 gress of science will soon settle the question. 



Partial displacement of the head of the hu- 

 merus downwards has been observed to be the 

 result of chronic rheumatic disease of long 

 standing ; but after much diligent inquiry in 

 museums and in books, I can find but two 

 well-marked specimens of this morbid change. 

 The most remarkable of these specimens is a 

 left scapulo-humeral articulation, which is 

 contained in the museum of the College of 

 Surgeons, Dublin. The history of the case 

 is unknown : the preparation formed part of 

 the collection presented by Dr. Kirby to the 

 College of Surgeons in Dublin. The head of 

 the left humerus in this specimen is greatly 

 enlarged, and a proportionate glenoid cavity 

 has been formed to receive it. The head of 

 this bone had descended so much beneath its 

 ordinary situation, that a new glenoid cavity 

 had been formed to receive it on the axillary 

 border of the scapula. The lower part of the 

 old glenoid cavity was still partially occupied 

 by the enlarged head of the humerus, but the 

 new addition to the cavity extends down- 

 wards for the space of an inch and half 

 below its ordinary situation. The new glenoid 

 cavity is enamelled on its surface, and en- 

 larged on its posterior margin by several 

 irregular-shaped bones of new formation. The 

 capsular ligament in this case has been partly 

 ossified.* 



If we look over the engravings in Sandi- 

 fort's Museum Anatomicum, we shall find, 

 we think, a specimen of partial displace- 

 ment of the head of the humerus downwards, 

 the result of this chronic rheumatic dis- 

 ease. The writer of the catalogue considers 

 the specimen to have been the result of acci- 

 dent, and has appended a history to the case, 

 giving an account of somewhat equivocal 

 symptoms. Whether these symptoms, such 

 as extensive effusion into the cavity of the 

 joint, of crepitus having been felt on the mo- 

 tions of the bones on each other, were the re- 

 sult of accident or of disease, their origin is re- 

 ferred to accident. When we carefully compare 

 the engraving with what we have seen of other 

 specimens of this disease elsewhere, we must, 

 we think, come to the conclusion, that this 



* See Catalogue of the Museum of the College of 

 Surgeons, Dublin, pp. 406905. &c. See also plate 

 IX. Jig. 7. of a work on chronic rheumatic arthritis, 

 shortly to be published by the writer ; illustrated 

 by lithographic drawings of natural size. 



example adduced by Sandifort must be con- 

 sidered as the result of chronic rheumatic 



Fig. 431. 



Scapula and portion of the clavicle connected to it, 

 viewed externally.* 



a, glenoid cavity ; b, a fragment of bone appa- 

 rently of new formation ; c, anterior part of acro- 

 mion separated from the spine of the scapula and re- 

 united to it ; d, extremity of the coracoid process ; 

 e, clavicle adhering to the acromion broken off from 

 the spine of the scapula. The acromion process was 

 depressed, and "omnem motum claviculse seque- 

 batur." (After Sandiford.) 



arthritis of long standing, with partial displace- 

 ment of the altered head of the humerus down- 

 wards (fig. 431.). Upon looking at the wood- 

 cut we notice the acromio-clavicular ar- 

 ticulation enlarged as if from chronic rheu- 

 matic disease. The acromion process is divided 

 into two portions ; a phenomenon we have so 

 frequently noticed to accompany this disease 

 of the shoulder joint (see p. 587.). We also 

 notice the additional portions of bone of new 

 formation attached to the capsular ligament 

 so common in this disease, and the addition of 

 an osseous margin to the glenoid cavity ; all 

 these circumstances, so well seen in the origi- 

 nal drawing to be found in Sandifort's work 

 as large as nature, we have attempted, in a re- 

 duced form, to repeat here. 



Finally, the head of the humerus may be 

 not only displaced partially upwards as the 

 result of this chronic rheumatic disease, par- 

 tially inwards, and, as we have just proved, 

 also partially downwards, but the most re- 

 markable abnormal appearances the writer has 

 witnessed from this chronic disease, has been 

 in two specimens contained in the Museum of 

 St. Bartholomew's Hospital, in which it will 

 be found that the head of the humerus, which 

 had been affected by this chronic disease, was 

 thrown completely backwards on the dorsum 

 of the scapula. In this case the displacement 

 was double, and two new glenoid cavities had 



* Diminished drawing from one in Sandifort's 

 Museum Anatomicum, vol. iv. table 25. jig. 2. 



Q Q 4 



