DISLOCATION OF THE FEMUR. 
565 
Fig. 2. 
The head of the femur, in man, may fracture within the 
acetabulum, and is termed an intracapsular fracture ; an 
injury which, so far as I can ascertain, has never been seen 
in animals. 
It is due to fragility of bones, and rigidity of joints, and 
the exciting cause is often insignificant, such as a slip or 
a fall. 
When the ligaments are ruptured, as they are more or less 
invariably, the parts are never absolutely restored to their 
pristine condition. Yet the animals may go sound. Often, 
as you see in the pelvis I hold in my hand, the cartilage 
of incrustation disappears both from the head of the femur 
and acetabulum. The bony surfaces exposed to friction 
acquire a hard, brittle, shiny aspect, due to an increased 
deposit of bone earth, and this transformation is termed 
eburnation of bone or joorcelainous deposit. This is more often 
case of dislocation as interesting, in showing the value of the method of 
reduction ; it is now doubly so, as it was an instance of a singularly hidden 
condition of parts hitherto undescribed. 
