SPAVIN 



SPAVIN 



73 



This is one of the most serious and troublesome diseases with which 

 the surgeon has to contend. It is an affection of the antero-internal 

 portion of the hock, and our reasons for treating the disease here will 

 be gathered from the description which follows. It is a disease which is 

 extremely common, and, notwithstanding the great amount of work which 

 has been done in this connection in the past, several phases remain to this 

 day in obscurity. There is scarcely a veterinary writer who has not at 

 some time or other had his attention attracted to it, whilst it is more or 

 less exhaustively dealt with in all surgical text-books. 



The area affected is usually the inferior third of the antero-internal 

 portion of the joint. The bones of this portion are the cuneiform magnum, 

 cuneiform parvum, scaphoid, the upper end of the inner small metatarsal, 

 together with the inner portion of the proximal extremity of the large 

 metatarsal. These bones form between them a number of synovial joints 

 of the arthrodial class. Movement is, however, restricted in the joint 

 formed between the large and inner small metatarsal bones by the ossifica- 

 tion of the interosseous ligament which unites these bones to one another 

 in the immature animal. There is free movement, however, in the joints 

 formed by the cuneiform bones and the scaphoid, and also between the 

 cuneiform bones and the metatarsals. These joints are all supplied by 

 synovial membranes, and the surfaces of the bones which come into 

 apposition with one another at the joints are clothed, with articular 

 cartilage (for a fuller description see the chapter on joints). 



From our description of the bones it will be remembered that a 

 roughened ridge extends transversely across the front of the scaphoid, and 

 that this ridge is continued on to the inner edge of the bone. Another 

 ridge, parallel to the one just mentioned, is found on the cuneiform magnum. 

 This latter ridge is slightly the more prominent, and extends on to the inner 

 aspect of the joint. Between these two ridges is a transverse groove, at 



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