704 
bffiEASfiS Of 1 THE LEG. 
aseptic, a window may be left in the plaster bandage, to allow the 
wound to be inspected and kept relatively aseptic. 
III.—RUPTURE OF THE TIBIO-FIBULAR INTER¬ 
OSSEOUS LIGAMENT. 
Fractures of the fibula have rarely been recorded in animals ; they 
are certainly very difficult to detect during life. In dogs, however, the 
fibula is usually involved in cases of fracture of the tibia. Behnke, in 
a mare, saw rupture of the interosseous ligament, with separation of the 
fibula from the tibia, from the animal shying whilst being ridden. 
Severe lameness at once followed, and though it gradually diminished, 
it recurred after lying down and rising. The limb was carried stiffly, 
and no weight was placed on it. Post-mortem examination showed the 
fibula to have been torn away from the tibia ; it lay amongst the muscles 
of the thigh, which it had severely injured. 
IY.—RUPTURE OF THE FLEXOR METATARSI MUSCLE. 
In the horse the tendinous portion of the flexor metatarsi muscle forms 
an inextensible cord, which unites the stifle and hock joints in such a 
way that movement of one joint produces movement of the other, and 
permits the muscles of the quarter and thigh to assist in extension of the 
hock-joint. The tendon arises from the pit between the trochlea and the 
external condyle of the femur, in common with the extensor pedis, passes over 
the stifle-joint, lying in front of the tibia, at the upper end of which it is 
surrounded by a mucous bursa, and is inserted by three slips into the hock 
and metatarsus. In ruminants the muscle is also provided with much 
tendinous tissue, but arises from the tibia. In carnivora it is replaced by a 
tendon which starts from the internal surface of the tibia and is inserted into 
the bones of the tarsus, serving to prevent excessive extension of the hock- 
joint. 
In the horse, rupture of this muscle is attended with such marked symp¬ 
toms that attention was early directed to it. Solleysel described the disease, 
though he regarded the tendon as a nerve. At the end of the eighteenth 
century the disease was described by Louchard as dislocation of the hock-joint. 
Bouley, in 1833, correctly explained the condition, and was followed by Bigot, 
who made the experiment of dividing the muscle. Hertwig first thoroughly 
described the affection, and gave a fuff account of its origin. 
The flexor metatarsi becomes ruptured either in its course along the front 
of the tibia or at its origin from the pit between the trochlea and external 
condyle of the femur. In the former case the rupture is usually incomplete, 
the fibres appearing as though frayed but not completely torn across. 
Causes. Rupture of the flexor metatarsi follows excessive extension 
of the hock-joint, produced either by the animal kicking violently or 
struggling in hobbles, or from the limb being violently drawn backwards, 
as in shoeing in the travis, or drawn upwards by means of a cord passed 
