FRACTURE OF THE BONES OF THE HOCK. 
713 
The symptoms are: sudden and severe lameness, shortly followed by 
fluctuating painful swelling of the astragalo-tibial joint, similar to that in 
inflammation of the hock-joint. Crepitation can sometimes be detected 
by placing both hands around the joint and moving the lower part of 
the limb ; but in other cases it is absent, and the condition may be 
mistaken for violent strain of the joint, which, however, is rare, or for 
severe subfascial cellulitis ; but as the latter is accompanied by swelling 
of the local lymph vessels and by fever, it is sufficiently distinct from 
fracture of the astragalus. 
Prognosis is absolutely hopeless, because the fracture always extends 
into the joint, recovery is extremely protracted, and no weight can be 
placed on the limb. It is therefore better to slaughter large animals 
without delay. An attempt at treatment may be made in cats and 
dogs by applying a plaster bandage, which should be put on whilst the 
leg is moderately extended, so as to limit as far as possible the lameness 
which will result from obliteration of the joint. The cases described by 
Furnaletto certainly recovered, but proved permanently lame. 
(c) Fractures of the other bones of the hock are less frequent than 
those above mentioned, and are either due to kicks, to the animal being- 
run over, or to similar violent mechanical causes, or they appear in con¬ 
nection with sprains and luxations. Thus Ptey found dislocation of the 
hock-joint between the scaphoid and cuneiform magnum in a horse 
which had caught its hoof between railway-metals and had fallen. The 
external small metatarsal was torn away from the large metatarsal and 
the cuboid bone crushed. 
Diagnosis is seldom difficult, though the seat of fracture can only be 
determined by post-mortem examination. There is abnormal mobility of 
the hock-joint, especially for movements of ad- and ab- duction ; crepita¬ 
tion is often audible. 
The prognosis is generally bad, but depends on the degree of lameness, 
and is, of course, influenced by the presence or absence of other injuries 
and the nature of the animal’s work. 
II.—LUXATION AND SPRAIN OF THE HOCK-JOINT. 
The strong ligamentous apparatus and the interlocking of the grooves 
and depressions on the astragalus and tibia respectively form so perfect 
a means of union that luxations of this joint must necessarily be of the 
rarest occurrence. In horses, it is doubtful if any have been reported, 
for even Louchard’s case appears only to have been a severe strain, 
probably accompanied by fracture of the malleoli of the tibia or of the 
astragalus bone. Stockfleth describes having discovered by post-mortem 
examination inward luxation of the astragalus in a sheep; the capsule of the 
joint was ruptured. He also saw displacement between the astragalus and 
