598 



ABNORMAL CONDITIONS OF THE SHOULDER JOINT. 



partially downwards, enlarging the axillary 

 margin of the scapula, so as to form a new 

 glenoid cavity ; and lastly, that the infra-spi- 

 natus fossa of the dorsum of the scapula may 

 become the new situation, to which the head 

 of the humerns may be transferred from the 

 effects of chronic rheumatic arthritis of the 

 shoulder. 



The writer has after much investigation 

 seen but two examples of this last displace- 

 ment, and, curious to observe, these were in 

 the right and left shoulder joint of the same 

 individual. 



Partial dislocation of the head of the humerus 

 imvards. In the museum of the College of 

 Surgeons, Dublin, we find a specimen pre- 

 sented by Professor Hargrave, which he con- 

 siders one of partial luxation inwards from 

 accident. The accidental origin of the af- 

 fection, however, cannot be proved, as the 

 history of the case is unknown ; and the spe- 

 cimen presents so many of the features of the 

 chronic rheumatic disease combined with the 

 partial luxation, that we are of opinion that 

 Professor Hargrave's specimen cannot be 

 considered the result of accident ; but that all 

 the appearances it presents are the conse- 

 quence of long established chronic rheu- 

 matic arthritis. We shall here give an ab- 

 stract of Dr. Hargrave's case, referring for 

 a fuller account to the Edinburgh Medical 

 Journal. 



The capsular ligament presented a perfect 

 state of integrity along the superior and pos- 

 terior part of the joint. It was very dense and 

 strong, extending from the acromion process 

 downwards and forwards towards thehumerus. 

 When the capsule was opened on its internal 

 aspect, the head of the humerus was seen to 

 be in part external to the joint, and was di- 

 vided into two unequal portions by a deep 

 groove extending for the entire length of its 

 head in a perpendicular direction. Of these 

 two portions the internal and larger one 

 passed a small distance beyond the corre- 

 sponding edge of the glenoid cavity into the 

 subscapular fossa, while the posterior and 

 smaller one remained in the glenoid cavity, 

 occupying its internal surface. 



The groove now mentioned fitted on the 

 inner edge of the glenoid cavity, which did 

 not present its usual well defined border, but 

 was rounded off, so as to present a thick lip, 

 from the constant pressure and frequent mo- 

 tion of the humerus upon it. The head of the 

 humerus in its superior aspect was in close 

 apposition with the coracoid process, and 

 had altered in a remarkable degree its form, 

 which in place of being beaked and point- 

 ed, was much expanded, flattened and slightly 

 hollowed. 



When the articulation was first opened, the 

 tendon of the long head of the biceps could 

 not be seen ; but on more particular examina- 

 tion it was found to have been ruptured, the 

 portion connected with the muscle being in- 

 timately attached to the bicipital groove of the 

 humerus, while the portion belonging to the 

 glenoid cavity was much diminished in size, 



and presented a mere rudimental character 

 in the capsular cavity.* 



When we carefully observe this specimen, 

 we notice that it presents many of the general 

 anatomical characters of the chronic rheumatic 

 arthritis, these appearances being of course 

 modified, as to the external shape of the sur- 

 faces, by the special peculiarity of the partial 

 displacement which had in this case occurred. 



The head of the humerus was much en- 

 larged and mis-shapen. It was found that a 

 large portion of the new articular cavity for 

 the head of the humerus lay on the sub- 

 scapular fossa, but that a portion of the old 

 glenoid cavity remained, and that the head of 

 the humerus, divided into two surfaces, arti- 

 culated with both the new and old glenoid 

 cavity. The effects of friction during the 

 movements which took place between the 

 bifid head of the humerus and the double 

 articular cavity, which corresponded to it, 

 were such that perfect and complete ebur- 

 nisation of parts of the contiguous surfaces 

 took place. This last circumstance could 

 not be said to amount to proof, that chronic 

 disease rather than accident had caused the 

 partial luxation. In addition to the ivory-like 

 enamel, we find also that bony vegetations, or 

 granular nodules of new bone, surround the out- 

 line of the new articular surface formed for 

 the head of the humerus; and that small foreign 

 bodies, like sesamoid bones, are seen bordering 

 the edge of the articular cavity posteriorly. 

 All these minor circumstances remind us of 

 the anatomical characters we have found in 

 examining cases of chronic rheumatic arthritis 

 of the shoulder. The coracoid process, we 

 are informed, had altered in a remarkable 

 degree its form, which had become expanded, 

 flattened, and slightly hollowed; irr a word, it 

 became articular, as we have often before 

 found it to be, as the result of chronic rheu- 

 matic arthritis. The glenoid ligament (Pro- 

 fessor Hargrave's case) was absent ; and the 

 following description, which we may be ex- 

 cused for recopying, may well be applied, we 

 think, to the ordinary condition of the tendon 

 of the biceps in most of the cases of chro- 

 nic rheumatic arthritis of the shoulder. 



" When the articulation was first opened, the 

 long tendon of the biceps could not be seen, 

 but on more particular examination it was 

 found to have been ruptured, the portion con- 

 nected with the muscle being intimately at- 

 tached to the bicipital groove of the humerus, 

 while the portion belonging to the glenoid 

 cavity was much diminished in si/e, and pre- 

 sented a mere rudiment." 



We have already made the remark, that 

 when the shoulder joint is the seat of chro- 

 nic rheumatic arthritis, the neighbouring 

 acromio-clavicular articulation is frequently 

 affected with this same disease. Now, in care- 

 fully examining Professor Hargrave's specimen, 

 we shall find that not only do the anatomical 

 characters which belong to chronic rheumatic 



* See Catalogue of the Museum of the R. C, of 

 Surgeons, Dublin, vol. ii. p. 397. Edinburgh Medical 

 and Surgical Journal, for October, 1837. 



