A patella fracture is usually a split in your kneecap, the bone that handles your knee joint. It’s usually due to a traumatic injury, like a slide or a blow on your kneecap. Grade IV: The Pet will wander with rear inside of a crouched place, the patella is completely displaced https://www.theorthopaedicandpainpractice.com/what-are-patella-fractures/