FRACTURE OF THE NAVICULAR BONE. 
633 
volar flexion. The toe is directed obliquely backwards and downwards. 
Marked paid is caused by lifting the foot and extending the coronet- 
joint (dorsal flexion) by pressure on the toe. Inflammatory swelling 
occurs later in the hollow of the heel. 
This fracture is distinguished from acute disease of the navicular bursa 
by the sudden appearance of lameness, and, at the commencement at 
least, by the absence of swelling from the hollow of the heel. 
Prognosis is unfavourable, particularly in compound fractures, caused 
by picked-up nails. There is always danger of the perforans tendon 
being injured, and, later, ruptured, by the sharp edges of the fragments, 
or by the callus, or of chronic lameness appearing, hence complete 
recovery is extremely unlikely. 
Treatment is only advisable in valuable animals, like those used for 
the stud. Complete rest is of first importance if the fracture is sub¬ 
cutaneous. At a later period plantar neurectomy might be performed. 
In complicated fracture caused by picked-up nails, resection of the 
perforans tendon may be attempted. Humbert, in such a case, claims 
to have completely resected the navicular bone with success. The foot 
was irrigated night and day for a month after operation. In two and a 
half months the animal could trot sound. Moller, who made experi¬ 
ments in this direction, failed to obtain good results, and he seems to 
entertain considerable doubt of the possibility of cure by resection of the 
navicular bone. 
X.—NAVICULAR DISEASE. 
In England, during the latter half of the eighteenth century, attention was 
first directed to a disease which had become unusually common in thoroughbred 
horses. At first it was regarded as a disease of the pedal-joint, or was 
mistaken for contraction of the foot. It is now impossible to say whether the 
disease described by Bridges and Gibson as “ grain of the coffin-joint ” was 
identical with that now under consideration. Moorcroft states that he had 
previously seen the disease, though he had not directly recognised it. In a 
letter dated 1804, Moorcroft warns his correspondent against mistaking simple 
contraction of the foot for coffin-joint lameness. He describes the first 
condition,,and states that it only occurs secondarily in this disease. Coleman 
and Turner further observed and described the condition, at first under the 
title of “ coffin-joint lameness,” and later of “navicular disease,” or 
“ navicular lameness.” The French “ maladie naviculaire ” is derived from 
this. 
In Germany the disease was also first termed “ coffin-joint lameness.” 
Benner endeavoured to more particularly identify the seat of the disease by 
distinguishing an anterior and a posterior coffin-joint lameness, and only 
applied the latter term to the disease now in question. Sticker proposed the 
term “ podarthrocace.” At that time “ arthrocace ” was a term applied to 
various chronic joint diseases. Brauell first described the disease thoroughly, 
and named it “ podotrochilitis.” Both names—“ navicular disease ” and 
‘ podotrochilitis ”—have the merit of at least indicating the seat of the 
