FRACTURES OF THE BONES OF THE KNEE. 
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the fascia becomes attached to the ligaments of the joint, to the lower extremity 
of the radius, and to the inner small metacarpal, and covers the flexor pedis 
tendons, with which it becomes continuous. 
The skin lies immediately over the fascia, and, on the dorsal side especially, 
is thick, tense, and provided with a moderately well-developed subcutis. Sub¬ 
cutaneous bursae are sometimes found on the os magnum, as well as on the 
lower anterior surface of the radius towards the inner side of the sheath of the 
extensor pedis. The discharge of synovia after injury to the front of the knee 
is therefore no proof that the knee-joint has been opened, although it always 
calls for special precautions in treatment. 
I.—FRACTURES OF THE BONES OF THE KNEE. 
Fracture of these bones is in general prevented by their small size and 
sheltered position. In large animals like horses, fractures are commonest 
from falls on hard ground. They usually occur in conjunction with wounds 
and injuries of the joint, i.e., they are compound, and the fragments 
seldom unite; but when this does occur movement of the joint is more 
or less limited, or altogether prevented by formation of synostoses. 
On account of its isolated position the pisiform bone is an exception to 
the above rule, and Moller has repeatedly seen fracture of it in race¬ 
horses. A case occurred in a draught-horse during heavy work, the 
immediate cause being excessive contraction of the flexors of the knee. 
One or other ligament of the pisiform bone may also be ruptured. 
The symptoms are, inability to bear weight on the limb which is flexed, 
as in complete radial paralysis, and local pain. Abnormal mobility of 
the pisiform bone and crepitation under pressure reveal the character of 
the fracture beyond doubt. On the other hand, fractures of the other 
carpal bones produce very ill-defined symptoms; though in most cases 
the sudden appearance of severe lameness (“supporting leg lameness”) 
and local pain about the knee-joint sufficiently indicates the seat if not the 
exact nature of the lesion. 
Course. Union of fractures of the pisiform bone is difficult. The 
fragments of bone are drawn upwards by the pull of the attached 
muscles, and, as in fractures of the ulna, the conditions are unfavour¬ 
able to callus formation. A fibrous callus forms, general^ of insufficient 
strength, and if put to work too soon the animal relapses. In other cases 
the knee shows marked dorsal flexion. Even favourable cases last for 
two to three months ; but many horses have to be destroyed in conse¬ 
quence of laminitis and descent of the os pedis, and of the resulting acute 
pain, fever, &c. Compound fractures of the knee bones often end in 
septicsemia and death. Should recovery occur, there is usually extensive 
callus formation and loss of function in the joint, so that the animals are 
of little use except for stud purposes. 
Treatment. The animal should be placed in slings and reposition 
