964 RUPTURE OF THE STRAIGHT LIGAMENTS OF THE PATELLA. 



ligaments to be 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 inclined forwards (vertical luxation), and 

 the bone 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 bone in its proper position by a dressing, 

 and for a time proved successful, but had to be given up in consequence 

 of their causing inflammation 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, but 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 stej)s without assistance. Previously it 

 had been unable to make even a single step without the patella becoming 

 displaced. Unfortunately it died from intercurrent disease. 



Dollar saw a somewhat similar case which is described and illustrated in 

 v " 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 con- 

 sisted in absolute rest : one patient was sufficiently improved in 

 three weeks, the other in a month, to allow of their leaving hospital. 



Voigt lander 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 

 relaxation of the straight ligaments. The animal was slaughtered, 

 and the rupture confirmed by post-mortem. 



IV.— FRACTURE OF THE PATELLA. 



Fracture of the patella is rare, and up to the present has only 

 been seen in horses. Kicks, collisions, and falls with the stifle-joint 

 strongly flexed are the principal causes. Wollstein reports a case 

 produced by struggling in hobbles, whilst Renault saw double-sided 



