602 
FRACTURES OF THE PHALANGES. 
the limb must of course be at rest, otherwise it would be impossible to 
properly estimate the degree of local pain. It is only after the lapse of 
some time that periostitis or exostosis can be detected at the upper end 
of the bone. 
In solipeds fractures of the os coronas are caused in the same way as 
those of the os suffraginis. They are a common sequel of the foot being 
caught between railway-metals. The bone is either split longitudinally, 
or may he broken into several fragments. Henon saw the os coronae 
broken into seven, Schrader into six, and Lafosse into twenty pieces. 
Henon saw a horse with fracture of the os coronae in all four feet; some¬ 
times only the ligamentous prominences are torn away. Moller mentions 
a case in which the hone was fractured into a number of pieces by a nail 
penetrating through the frog. Fissure and simple fracture are rarer in 
this bone than in the os suffraginis. 
Fracture is detected in the same way as in the suffraginis, and 
when complete offers no difficulty. Crepitation in this region points to 
fracture of the os coronae, provided the suffraginis is known to be intact. 
Fracture of the os pedis is comparatively rare, though it has been 
seen by a number of observers. It is caused in the same way as fracture 
of the other phalanges, ?.<?., by slips, particularly when animals are 
suddenly reined-up; but fracture of the pedal hone also follows injury 
by picked-up nails. Fracture is common in horses which have been 
“unnerved.” In this case its occurrence is partly explained by loss of 
sensation in the foot producing abnormal action, partly by alteration in 
the nutrition of the foot and changes in the bone. It is well known that 
after chronic lameness the nutrition of the bones of the affected limb 
generally suffers. According to Williams, fracture also results from 
the heels of the shoe being caught in railway-points, and, in heavy 
horses, from falls. Lemliofer saw fissure of the os pedis produced by 
the horse striking the foot against a wall when jumping. This fracture 
united in four months, Schrader also noted fractures of the ossified 
lateral cartilage. 
Diagnosis is very difficult, crepitation being rare. Only occasionally 
can it be produced by rotating the foot or pressing the heels together, 
and in its absence the diagnosis must be arrived at by a process of 
elimination, and by considering the history. Fracture of the os pedis 
may be surmised when severe pain is shown on attempts to place weight 
on the foot, when the lameness is of sudden onset and attended with 
marked volar flexion, and when, at the same time, there is no acute 
inflammation of the flexor apparatus or in the hoof. Increased pulsation 
in the arteries does not occur until twenty-four hours after fracture. 
Wustefeld found the superficial veins of the foot greatly swollen. 
Examination with farriers’ pincers generally, though not invariably, 
