DISEASES OF THE BONES 401 
Wo slight evidence of navicular disease. The articular 
* cartilage of the corono-pedal joint had been almost com- 
pletely removed, and there was sclerosis of the opposed 
bony surfaces, which by unequal wear had brought about 
~ deformity of the os corone and os pedis. 
' ‘There was very old-standing fracture of the pyramidal 
process (see Fig. 157), with the formation of a false joint 
between the process and the pedal bone. There was also a 
recent fracture of the part of the pedal bone which carries 
the articulation for the navicular bone, and this and the 
tendon lesions probably accounted for the final symptoms 
of ‘break-down.’ 
Neurectomy enabled us to get a year’s useful work out 
of what would otherwise have been a hopeless cripple.* 
C. FRACTURES OF THE BONES. 
More or less by reason of the protection afforded them by 
the hoof fractures of the bones of the foot are rare. When 
occurring they are more often than not the result of direct 
injury, as, for example, violent blows, the trapping of the 
foot in railway points, the running over of the foot with 
a heavily-laden waggon, or violent kicking against a gate or 
a wall. They occur also as a result of an uneven step upon 
a loose stone when going at a fast pace, and as a result of 
sudden slips and turns, in which latter case they are met 
with when animals have been galloping unrestrained in a 
field, or when an animal, ridden or driven at a fast pace, is 
suddenly pulled up, or just as suddenly turned. 
At other times fractures in this region take place without 
ascertainable cause, and cases are on record where animals 
turned overnight into a loose box in their usual sound 
condition have been found in the morning excessively lame, 
and fracture afterwards diagnosed. 
* A. R. Routledge, M.R.C.V.S., Journal of Comparative Pathology 
and Therapeutics, vol. xvi., p. 871. 
26 
