Femoral Head Ostectomy (FHO) surgery is a common orthopedic procedure for cats experiencing debilitating hip joint issues. It aims to alleviate discomfort and restore functional mobility. FHO surgery provides a viable option when conservative treatments are insufficient or more extensive surgical repairs are unsuitable, helping cats regain a comfortable and active life.
What FHO Surgery Involves
FHO surgery involves removing the “ball” portion of the hip joint, known as the femoral head, and part of the femoral neck. In a healthy cat, the hip is a ball-and-socket joint where the femoral head fits securely into the acetabulum of the pelvis, allowing smooth, pain-free movement. When this joint is damaged or diseased, bone-on-bone contact causes significant pain and inflammation.
Removing the femoral head and neck eliminates this painful friction. The leg muscles initially hold the femur in place, and over time, the body forms a “false joint” or pseudoarthrosis. This false joint consists of scar tissue that develops between the empty acetabulum and the remaining femur, providing a cushioned, pain-free articulation for movement. This adaptive process allows many cats to regain considerable mobility.
Reasons for FHO Surgery
Several conditions can necessitate FHO surgery in cats, typically arising from trauma, congenital issues, or degenerative diseases. Common indications include traumatic injuries, such as fractures of the femoral head or neck, especially when complex surgical repair is not feasible. These fractures often result from accidents and cause severe pain and instability.
Hip luxation or dislocation, where the femoral head separates from the acetabulum, is another frequent reason for FHO, particularly if the hip cannot be manually reduced or repeatedly dislocates. Severe osteoarthritis, characterized by cartilage erosion and painful bone-on-bone grinding, also makes FHO a suitable option when conservative management fails. Less common in cats than dogs, Legg-Calve-Perthes disease, involving avascular necrosis of the femoral head, also warrants FHO due to its spontaneous degeneration and pain.
The Surgical Procedure
The FHO surgical procedure is performed under general anesthesia for the cat’s comfort and immobility. The veterinary surgeon makes an incision over the hip joint to access the affected area. The surgeon then precisely removes the femoral head and neck, creating space within the hip joint to prevent bone-on-bone rubbing.
After removal, the incision is meticulously closed with sutures. The cat is then closely monitored during recovery from anesthesia. The primary objective is to eliminate pain and facilitate the formation of a functional scar tissue joint that supports future movement.
Recovery and Rehabilitation
The recovery period following FHO surgery significantly influences the cat’s long-term outcome. Immediately after surgery, pain management is a priority, involving prescribed medications such as non-steroidal anti-inflammatory drugs (NSAIDs). The surgical site requires careful monitoring for redness, swelling, or discharge, and an Elizabethan collar is often used to prevent licking or chewing. Activity must be strictly restricted during the first 10-14 days, typically confining the cat to a small room or crate to prevent strenuous movements that could disrupt healing.
Early rehabilitation often includes gentle passive range-of-motion (PROM) exercises, where the owner or therapist carefully moves the hip. Approximately one week after surgery, physical activity is gradually increased to rebuild muscle mass and strengthen the joint. This progressive activity helps prevent the scar tissue in the developing false joint from becoming too stiff, ensuring better flexibility. Exercises like slow, controlled walking, especially up stairs, or gentle water therapy can be beneficial. The full recovery timeline typically ranges from six weeks to several months, requiring consistent adherence to veterinary instructions.
Life After FHO Surgery
Following successful FHO surgery and complete rehabilitation, most cats adapt well, experiencing a significant reduction in pain and an improved quality of life. Many cats regain essentially normal function of the affected leg. While a slight limp or altered gait might be noticeable, these changes are typically minimal and do not impact the cat’s overall well-being or activity levels.
Cats with a healthy weight and good muscle mass before surgery tend to have better outcomes, as their muscles help stabilize the newly formed false joint. Long-term management involves maintaining an ideal body weight and potentially using joint supplements to support hip health. With appropriate post-operative care, cats can return to their regular activities, including jumping and playing, enjoying a comfortable and active life.