Femoral Head Ostectomy (FHO) in Dogs

The primary goal of an FHO is to remove bone-on-bone contact, restoring pain-free
mobility. An FHO restores mobility to the hip by removing the head of the femur. This
removes the ball of the ball-and-socket joint, leaving just an empty socket. The muscles
of the leg will initially hold the femur in place and, over time, scar tissue will form
between the acetabulum and the femur to provide cushioning that is referred to as a
'false joint'. Although this joint is anatomically very different from a normal hip joint, it provides pain-free mobility in most patients.

The most common reasons for FHO include:

Fractures involving the hip. When a fracture involves the hip joint and cannot be
repaired surgically (either due to patient considerations or financial considerations for
the owner), an FHO may provide the best option for pain-free mobility.

Hip luxation/dislocation (associated with trauma or severe hip dysplasia). In some
cases, a hip that is out of the socket cannot be replaced with manipulation or other
medical means. Surgical repair of hip luxations can be costly and is not always
successful, so many dog owners elect FHO for small dogs with hip luxation.

Severe arthritis of the hip. In chronic, end-stage arthritis, the cartilage that protects both the head of the femur and the acetabulum can become eroded away, leading to painful bone-on-bone grating whenever the hip is moved. Performing an FHO can remove this point of contact and alleviate pain.

Legg-Perthes disease (also known as avascular necrosis of the femoral head). This  uncommon condition, most frequently seen in miniature and toy breed dogs, causes the bone within the femoral head to begin to die at an early age. The bone collapses due to these degenerative changes, leading to severe pain. Removing the femoral head via FHO removes the source of pain for the dog.