SPRAINS, 521, 
Already in 1852, Meyer attributed the cramp of solipeds and bovines 
to the displacement upwards of the patella; for him, this bone became 
fixed on the internal border of the femoral trochlea, where it was held 
by the internal and median tibio-patellar ligaments. It is the theory 
advocated by Bassi in Italy, Chuchu in France, and to-day admitted 
without discussion. The slight 
deviation of the patella is due, 
not to a luxation of that bone, 
but to the fact that the in- 
ternal border of the trochlea 
being higher and thicker than 
the external, the patella is 
somewhat thrown outwards. Lit 
But how can the patella as- 
sume that position and keep 
it?) What power holds it there ? tani 
Practice teaches that this ac- 
cident is principally met with 
in colts, in animals recently 
put to work, in weak and 
anemic subjects. It is thus 
that it manifests itself during 
the convalescence of some 
serious diseases (pneumonia, 
typhoid fever). A special 
conformation of the trochlea, 
specially of the kind of plate 
form which ends at its upper 
: : Fig. 112.—Stifle joint, 1.i., internal border 
extremity; the disappearance & > , cae 
S PP of the femoral trochlea; t.r.i., internal 
of the fatty eushious situated patellar ligament ; f.r., internal femoro- 
under the tibio-patellar liga- patellar ligament. 
ments and above the trochlea, 
under the insertion of the triceps cruralis; the violent or incoordinated 
contractions of the muscles; the dry condition of the joint; all those 
are the causes of the accident. 
The hooked condition is kept up by the stretching of the internal and 
middle tibio-patellar ligaments, of the first one principally. Violet has 
erroneously attributed it to a contraction of the patellar muscles. 
Submit the young subjects to a methodical training, and give a repair- 
ing diet to those weakened by serious or long disease; such are the two 
principal prophylactic measures. 
The accident exists; the patella must be returned to its place. A 
