Dislocation of the patella

The patella is a small bone triangular shape that ensures the movement of the stifle (knee equivalent in humans) sliding in a groove called bone trochlea, located at the end of the femur. During dislocation, the patella out of the groove and moves to the side. Medial dislocation of the patella (dislocated inwards) is common in many small breeds. This is a problem of bone architecture in the small dog, the trochlea is not enough ground, the ligament underlying the patella slides on the cartilage, which causes instability of the patella. This instability may be temporary and does not lead necessarily to surgery.