RUPTURE OF THE STRAIGHT LIGAMENTS OF THE PATELLA. 693 
which the horse could sometimes walk for several steps-in the usual way; 
suddenly, however, the patella again became displaced, and all the symptoms 
returned. 
The post-mortem showed the inner lateral and inner and middle straight liga¬ 
ments to he diseased and elongated, allowing the lower border of the patella 
to ride up over the outer lip of the trochlea, and become fixed there. The 
upper border of the patella then inclined forwards (vertical luxation), and the 
hone itself slipped outwards to an extent of nearly 1 inch over the external 
condyle of the femur. When the patella was replaced, the ligaments named 
were seen to be distinctly relaxed. The continual pressure exercised by the 
lower border of the patella had caused absorption of the articular cartilage of 
the femur, and the formation in it of a distinct depression, corresponding in 
shape to the lower surface of the patella. Attempts were made during life to 
fix the hone in its proper position by a dressing, and for a time proved 
successful, hut had to he given up in consequence of their causing inflamma¬ 
tion and necrosis. The most effective appliance was a broad strap fixed to 
the slings, and buckled round both stifle-joints. 
A splint was so applied to the tibia as to exercise pressure on the outer 
surface of the patella, hut was only partially successful, though, after eight 
days of this treatment, the patella remained in position, and the animal could 
stand and even walk some steps without assistance. Previously it had been 
unable to make even a single step without the patella becoming displaced. 
Unfortunately it died from an intercurrent disease. 
Dollar saw a somewhat similar case, which is described and illustrated in 
“ Clinical Veterinary Medicine and Surgery,” p. 439. 
III.—RUPTURE OF THE STRAIGHT LIGAMENTS OF 
THE PATELLA. 
Moller describes two cases of rupture of the outer straight ligament in 
horses, the first case caused by the impact of a carriage-pole, the second 
probably by suddenly springing up in the stable. Both animals showed 
marked supporting leg lameness. At first no weight at all was thrown 
on the affected limb, and later, only a certain amount. The internal and 
middle straight ligaments could be felt below the patella, but the place 
of the lateral one was occupied by a depression. There was great pain 
on pressure below the patella, which, however, preserved its natural 
position. Treatment consisted in absolute rest: one patient was suffi¬ 
ciently improved in three weeks, the other in a month, to allow of its 
leaving hospital. 
Voigtliinder saw rupture of the straight ligaments in an ox. The 
symptoms were: inability to stand, severe inflammation around the 
stifle-joint, flexion of the limb, inability to extend the stifle, and relaxa¬ 
tion of the straight ligaments. The animal was slaughtered, and the 
rupture confirmed by post-mortem. 
