(44) HISTORY of the SOCIETr. 



w'h'"' u point out the changes that take place on the joint, when left un- 



reduced, as being our proper guide in judging what line of prac- 

 tice is to be followed in fuch cafes. An vinreduced luxation 

 may be defcribed in three firuations : The firft, when the parts- 

 are little changed from the ftate they are in, immediately after 

 dillocation happens. The fecond, where motion is beginning to- 

 take place, and when the foft parts become adapted to the di {lo- 

 cated ftate of the bones. And the laft, when a new joint is 

 formed. After the head of the bone is lodged on fome part of 

 the fcapula, it is found to confolidate the cellular membrane 

 and mufcular fibres under it, fo as to form a kind of foft focket 

 for itfelf, which, by the preffure of the cartilage on the end of 

 the humerus, and by the motion the arm admits of, gets a 

 fmooth furface. The burfal ligament torn on that fide next the 

 humerus, is pulled acrofs the glenoid cavity, and the mufcles 

 will be found in the ftate I have already defcribed. 



" After the inflammation and fwelling, confequent upon the 

 injury, have gone off, the patient will be plagued with pains in 

 the ftretched mufcles, and will be incapable of moving the joint^ 

 with eafe. The inflammation will however make the lacerated 

 parts grow together, fo as to obliterate the paflTage tlirough 

 which the head of the bone efcaped from the joint. This may 

 be reckoned a luxation in a recent ftate. After fome time the 

 muicles begin to adapt themfelves to the ftate of the bones, thofe 

 that were overftretched are lengthened, and the relaxed ones 

 contracfl, fo that the perfon is capable of moving his arm, and 

 by degrees the motion becomes more confiderable. The burfal 

 ligament now gets adhefions to the edges of the glenoid cavity, 

 over which it lies, and the opening in it, through which tlie 

 bone pafled, is filled up, fo that it embraces the humerus clofe- 

 ly. The torn pafllige in the foft parts has become as firm as if 

 no laceration had ever take place. The focket, formed in the 

 cellular fubftance, between the head of the humerus and the 



fcapula. 



