FEACTUEE OF THE SESAMOID BONES. 137 



I have seen one case of transverse fracture of the sesamoid 

 bones, both bones being involved. The diagnosis was difificidt, 

 as there was much swelling around the fetlock ; the toe was 

 elevated ; the fetlock pad came to the ground ; and there was 

 very great lameness ; and the symptoms were exactly like those 

 of rupture of the superior suspensory ligament. The horse, being 

 an old one, was destroyed. I do not see that there can be a 

 possibility of rendering an animal ser^^.ceable after an accident 

 of this kind. In the first place, it would be almost impossible 

 to keep the fragments in contact, owing to the tendency of the 

 fetlock to fall downwards and the toe to be drawn upwards by 

 the extensor pedis ; and, secondly, the sesamoids, articulating 

 by one surface with the metacarpal, the fetlock joint would 

 become anchylosed, and by the other surface forming a synovial 

 bursa, over which the perforans glides, the tendon would be- 

 come diseased to a considerable extent, constituting a permanent 

 lameness. 



Fracture of the navicular bone occurs in two ways ; first, by 

 direct puncture, as when a nail penetrates the frog. These cases 

 are rare, but they do happen ; the symptoms are excessive lame- 

 ness, presence of the foreign body, or of the wound from which 

 it has been removed, synovial discharge, abundant, often bloody, 

 and after a time mixed with flaky pus ; abscesses commonly 

 form around the coronet ; the animal suffers from a high degree 

 of irritative fever, and if not put out of his suffering, dies from 

 pain and exhaustion. It is of the greatest importance to know 

 if the bone be broken or not, as many cases of open navicular 

 joint recover when uncomplicated with fracture. 



In open joint without fracture, the pain and fever may be as 

 great at first as when fracture is present, but the discharge from 

 the wound will be synovial, straw-eoloured, or mixed with a small 

 quantity of odourless pus ; whereas, if the bone be broken, there 

 will be more or less continual oozing of blood from its cancel- 

 lated tissue, tinging the discharge with a dirty-red hue, and 

 giving it a foetid odour. When these symptoms are present, say 

 in two days after the injury, the animal had better be destroyed. 

 It is as well to wait, say for two days, as the colour may be due 

 to the oozing of blood from the soft structures, and not from the 

 bone. 



The other way in which the navicular bone is fractured, is 



