The hip in cats and dogs is very similar to that of a person. It is a ball and socket joint. The ball of the femur held in place by the neck of the femur, which attaches to the rest of the bone. The “socket”, or acetabulum of the pelvis is what holds the ball of the femur in place.
There are many abnormalities; some congenital, some acquired, which lead to an unhealthy painful joint. For example, young male cats are prone to injuring the growth plate of their femoral head. Many dogs can develop dysplasia (abnormal formation) which leads to instability of the hip joint and arthritis. Some patients can traumatically dislocate their hip, which can often be difficult to reduce. All of these are painful, and some cannot be reversed medically or surgically. These are the cases in which case an FHO may be a good choice.
During this procedure, the head and neck of the femur are removed. By doing this, the source of pain (inflammation associated with the joint) is removed. The body will then heal around the joint, creating a psuedo-joint. While a little wobbly at first, your cat or dog will acclimate and learn to use their new joint pain free.