592 



ABNORMAL CONDITIONS OF THE SHOULDER JOINT. 



racters of the chronic rheumatic arthritis, with 

 partial displacement upwards of the head of 

 the hnmerus. Sanditbrt also, we feel sure, 

 has fallen into the error of concluding with- 

 out proof, that this specimen of the bones of 

 the shoulder constituted an example of par- 

 tial luxation from accident (" luxatio ossis 

 humeri ab injuria externa "). The subject of 

 this case, he says, was a robust man: the head 

 of the humerus having been driven upwards 

 between the coracoid process and the acromion, 

 a new articular surface was produced, partly 

 on the upper narrow part of the glenoid 

 cavity, and partly 'on the root of the coracoid 

 process. This new articular surface, in its 

 centre porous, was as to its circumference 

 hard, polished, and ivory -like (" partim porosa 

 sed caetera valde polita ac quasi eburnea"), and 

 had been in habitual contact with the head of 

 the humerus. The latter was much enlarged, 

 and its circumference near the corona of the 

 head was much increased by the addition of 

 a hard rounded margin (" margine revoluto 

 calloso"). The wearing away of the upper 

 part of the great tuberosity, the eburnisa- 

 tion of the summit of the humerus where 

 it came in contact with the concavity of the 

 coraco-acromial vault, the preternatural con- 

 tact of the head of the humerus with the 

 under surface of the acromial extremity of the 

 clavicle, are also noticed. " Caput ossis 

 humeri amplitudine auctum, margine revoluto 

 calloso, in superficie articulari affert eandem 

 pra2ternaturalem glabritiem et duritiem, duin 

 in vertici, ubi tuberculum majus occurrit, 

 superficiera exhibet partim glaberrimam, par- 

 tim inequabilem, rugosam, quoe juxta sum- 

 mum humerum movebatur trituratione, etiam 

 locum habuisse inter marginem inferiorem 

 clavicula?, et verticem capitis humeri mani- 

 feste aj)paret ; subluxatio in superiora ergo 

 hie locum habuit."* 



Here we find the description of the bones 

 unaccompanied with any account of anatomi- 

 cal characters of the other structures of the 

 joints ; nor is there any proof adduced that 

 any accident had occurred to produce the 

 appearance noticed ; we may therefore, we 

 think, conclude, that the history of the case 

 was unknown. When we compare Sandifort's 

 description of the above case, accompanied as 

 it is with an engraving, with the account given 

 by us in the preceding pages of the dissection 

 of other cases of the chronic rheumatic ar- 

 thritis as it affects the structures of the 

 shoulder joint, we think we may safely con- 

 clude that this case, adduced by Sandifort as 

 an example of partial luxation of the head of 

 the humerus upwards from external injury, 

 must be considered as presenting in the bones 

 described the anatomical characters of chro- 

 nic rheumatic disease, as it very commonly 

 affects the bone of the shoulder joint. 



In the anatomical examination of advanced 

 cases of this disease of the shoulder joint, 

 which we have witnessed, in which there 



* Museum Anatomicum Sandifort, tab. cli. fiys. \, 

 2, 3. vol. iv. 



had been partial luxation of the head of the 

 humerus upwards when the deltoid mus- 

 cle has been cut through, the head of the 

 humerus has been usually found exposed, and 

 in absolute contact with the under surface of 

 this muscle, having passed through the upper 

 part of the capsular ligament. In such cases, 

 the head of the humerus has been found to 

 present the usual characteristic appearances of 

 this chronic rheumatic disease ; that is to say, 

 the cartilage has been absorbed, and its place 

 supplied by an ivory-like enamel. The arti- 

 cular portion of the tendon of the biceps has 

 also been removed, as well as all those parts 

 which in the normal state intervene between 

 the summit of the head of the humerus and the 

 under surface of the coraco-acromial arch. 

 The superior portion of the capsular ligament 

 itself has been found perforated ; and the 

 under surface of the coraco-acromial vault 

 excavated, and lias become a new and sup- 

 plementary socket for the head of the hu- 

 merus (fig. 429.). 



The explanation of the circumstance why the 

 superior and external part of the capsular liga- 

 ment has been found perforated by a large cir- 

 cular opening, through which the head of the 

 h umerus can pass, appears to be, that the effects 

 of the loss of the tendon of the biceps are 

 such, that the head of the humerus is at once 

 elevated by the deltoid, and kept habitually 

 pressed up against the under surface of the 

 acromion. The coraco-acromial vault now 

 becomes the articular socket for the head of 

 the humerus, more than the original glenoid 

 cavity. The head of the humerus assumes 

 altogether a new form ; its summit is ex- 

 panded, and at the same time smoothed by 

 the constant effects of use and friction ; the 

 anatomical neck is encroached upon, and 

 gradually the whole summit, including the 

 great and lesser tuberosities, becomes articu- 

 lar, these latter eminences being, as it were, 

 ground down and covered with a porcelainous 

 deposit (fig. 428.). As the upper portion 

 of the circular groove, called the anatomical 

 neck of the humerus, which normally gives 

 attachment to the capsular ligament of the 

 joint, has been removed, this attachment of 

 the capsule must be destroyed, and a large 

 opening will be found in it. This occurrence 

 is well illustrated by a case of chronic rheu- 

 matic arthritis of the shoulder joint, described 

 by Mr. Hamilton Labatt, who entitles the 

 case, " An excellent specimen of that chronic 

 disease of the shoulder joint which old people 

 are liable to ; as also an example of partial 

 luxation upwards, the result of slow disease." * 



The history of this case, as of almost all of 

 the same kind published, was unknown. The 

 subject was a female aged GO, brought into 

 the College of Surgeons for dissection ; the 

 muscular system well developed. The com- 

 mon integuments had been removed when 

 Mr. Labatt was called to witness the dissec- 



* Vide London Medical Gazette, 1838, vol. xxii. 

 p. 22. ; also Catalogue, Coll. Surgeons, Ireland, 

 vol. ii. p. o'JO. 



