A Femoral Head Ostectomy (FHO) is an orthopedic procedure used to alleviate chronic hip pain in animals, primarily dogs and cats. This procedure is generally considered a salvage operation, utilized when other joint-preserving options are unavailable. The goal of the FHO is to remove the source of the pain—the physical contact between the damaged ball and socket. It works by permanently eliminating the “ball” portion of the joint, allowing the body to form a cushioned connection instead.
Conditions Treated by FHO
A veterinarian may recommend an FHO when the hip joint has become irreparably damaged, leading to chronic pain and reduced mobility. One of the most frequent reasons for this surgery is severe hip dysplasia, particularly in small to medium-sized dogs (typically under 50 pounds) and in cats. The procedure is also necessary following certain fractures of the femoral head or neck that cannot be repaired using fixation methods. Chronic or recurrent hip luxation, where the ball consistently pops out of the socket, can also be resolved with an FHO. Legg-Calve-Perthes disease, avascular necrosis of the femoral head seen in small-breed dogs, is another condition addressed. For these conditions, the FHO eliminates painful bone-on-bone grinding and restores a degree of function.
Understanding the FHO Procedure
The FHO surgery is performed under general anesthesia and involves the precise removal of the femoral head and neck, which constitute the “ball” of the hip joint. The surgeon makes an incision and carefully cuts away the top portion of the thigh bone (femur). It is important to remove the entire femoral neck to ensure no bony prominence remains that could rub against the pelvis in the future.
Once the femoral head is excised, the surrounding muscles hold the leg in place. Over time, a “false joint,” known as a pseudoarthrosis, is created as scar tissue and fibrous connective tissue mature in the space. This newly formed cushion acts as a spacer, allowing the leg to move with less pain.
Post-Surgical Rehabilitation and Outcomes
The success of an FHO procedure is highly dependent on a dedicated post-surgical rehabilitation program, often starting shortly after the operation. Immediate post-operative care centers on pain management, typically involving prescribed medications for one to two weeks, and diligent monitoring of the incision site. Unlike many other orthopedic surgeries that require strict rest, FHO recovery encourages controlled activity early on to promote necessary muscle mass development and strength.
Physical therapy is a fundamental component of recovery and includes passive range of motion (PROM) exercises to maintain flexibility. Controlled weight-bearing exercises, such as short, slow leash walks on flat surfaces, are typically introduced within the first couple of weeks to encourage the pet to use the limb and build up the musculature that will stabilize the new joint.
The initial healing period generally spans about two to three weeks, but full functional recovery can take up to 12 weeks. The long-term prognosis is generally positive for small to medium-sized pets at a healthy weight, as the false joint can more easily support their body mass. While the pet may have a slightly altered gait, the primary goal of achieving a pain-free, functional limb is usually met. Ongoing controlled exercise is necessary to maintain muscle mass, which acts as the main stabilizer for the pseudoarthrosis.