The femoral head ostectomy (FHO) is a salvage procedure that can be performed on both dogs and cats of almost any age. The FHO removes the femoral head and neck of the femur in order to eliminate the bone-on-bone contact of the hip. This is done to alleviate pain associated with diseased or injured hip joints.
About The FHO
In cases of chronic, severe arthritis—where the protective cartilage of the femoral head and acetabulum has worn away—painful bone-on-bone grinding can occur with every movement of the hip. By removing the femoral head and neck, the FHO eliminates this painful contact point, offering relief when other treatments have failed. Conditions in which an FHO could be considered are: aseptic necrosis of the femoral head (Legg-Calvé-Perthes), joint laxity, hip luxation, osteoarthritis, fractures of bones comprising the hip, hip dysplasia, and complications of total hip replacement. After an FHO, the body creates a pseudoarthrosis (false joint) to stabilize the hip.
How Does the FHO Work?
The hip is a ball-and-socket joint, where the head of the femur (the ball) fits snugly within the acetabulum (the socket) of the pelvis. This configuration allows for smooth, multi-directional movement. When the hip is damaged or diseased, the fit between these two structures suffers, leading to pain, inflammation, and restricted mobility.
By surgically removing the femoral head and neck, the FHO eliminates the painful bone-on-bone contact. In place of the original joint, the surrounding muscles initially hold the femur near the socket. Over time, scar tissue develops between the femur and the acetabulum, forming a cushioning “false joint.” While this new joint isn’t identical to the original, it typically provides good, pain-free mobility for most pets.
How the Hip Joint Functions—and What Can Go Wrong
Under normal circumstances, the hip works much like a smooth, well-oiled ball-and-socket mechanism. The “socket” is formed by the acetabulum (part of the pelvis), while the “ball” is the head of the femur. Fit together, they allow your pet’s leg to swing, pivot, and rotate in nearly any direction—picture a universal joint on your favorite multi-tool.
However, when disease or injury strikes the hip, things can get a bit less fluid. If the femoral head and acetabulum no longer align as they should, the once-smooth motion of the joint becomes impaired. This mismatch can result from any number of problems—think chronic inflammation, bone degeneration, or traumatic injury. Ultimately, the resulting friction or instability leads to discomfort, limited movement, and, all too often, persistent pain for your furry friend.
When to consider the FHO
The FHO procedure should be considered when there is pain and lameness of the hip that cannot be alleviated by pain medication, weight loss, non-surgical, and/or other surgical procedures.
Procedure
A standard cranio-lateral approach to the hip is performed. The muscles around the hip are retracted and the coxofemoral (hip) joint capsule is opened. The femoral head is luxated from the pelvis and held in an externally rotated position to expose the femoral head and neck. The head and neck are transected using a surgical saw. The recommended line of transection is shown below, depicted by the blue line.
What to Expect on the Day of FHO Surgery
On the morning of your pet’s FHO surgery, you’ll typically be asked to withhold food to reduce the risk of complications under anesthesia—think of it as your pet’s version of “nothing by mouth after midnight” before their big debut. Once you arrive at the clinic, your pet will be admitted and prepared for general anesthesia.
During surgery, the veterinary team will closely monitor vital signs to ensure your pet’s safety. The procedure itself is performed through a hip incision, and the area will be closely prepped with meticulous attention to sterility.
After the operation, hospital stays can range from just a few hours to a couple of days, depending on how your pet is recovering and any individual medical considerations. Don’t be alarmed if your pet isn’t using the operated leg right away—this is normal in the initial phase post-surgery.
When it’s time to head home, you’ll likely notice a fresh incision on the hip. Sometimes sutures are visible, while other times dissolvable stitches are hidden beneath the skin. Most veterinarians will provide an Elizabethan collar (yes, the classic “cone of shame”) to stop your pet from licking or chewing at the incision site, giving the area the best chance to heal without interference.
Post-Operative Care
In the postoperative period, pain medications are prescribed for 1-2 weeks depending on surgeon preference. The incision needs to be monitored for 10-14 days for any signs of inflammation or discharge.
Initial Recovery and Pain Management
Because both bones and muscles are cut during the FHO procedure, early recovery focuses on pain control. All prescribed pain medications should be administered as directed by your veterinarian. Moist heat may be recommended in the first several days following surgery to provide comfort and decrease stiffness at the surgical site. In some cases, your veterinarian might suggest therapies such as laser treatment to help reduce inflammation and encourage healing.
Rehabilitation and Exercise
Unlike most orthopedic procedures, dogs and cats with FHOs are recommended to have controlled exercise and physical therapy early after surgery. This includes controlled weight bearing, range of motion exercises, and thrusting exercises. Physical rehabilitation has been shown to promote early weight bearing and enhanced function post-FHO.
Prognosis Following FHO Surgery
Most dogs experience a very good prognosis following FHO surgery. With appropriate pain management and a steady rehabilitation program, the majority of patients regain near-normal use of the operated leg. While there may be a mild reduction in range of motion or a slight shortening of the limb, these changes are generally minor and rarely interfere with a pet’s daily activities or overall quality of life. With proper post-surgical care, including early physical therapy, most pets return to comfortable, active lifestyles.
Recovery Timeline
Most pets begin to return to normal activities about six weeks after FHO surgery. Recovery may happen even more quickly in pets that were active and healthy prior to a sudden injury, as their muscles are typically stronger and rebound faster. In pets that have struggled with chronic hip issues for a longer time, the healing process may take a little longer, as muscle atrophy can delay regaining full strength and mobility. Each patient’s timeline will vary based on their health before surgery and their participation in post-operative physical therapy.
Long-Term Effects on Limb Function and Length
Following FHO surgery, most dogs and cats experience a return to near-normal use of the operated limb. While it’s common to notice a subtle reduction in the hip’s range of motion or a minor shortening of the leg, these changes generally do not interfere with daily activities or the animal’s overall comfort. The vast majority of patients go on to lead active, pain-free lives—running, jumping, and playing much as they did before surgery. Long-term outcomes are typically excellent, particularly with adherence to post-operative physical therapy.
Phases of Recovery Following FHO Surgery
Recovery after a femoral head ostectomy can be divided into two primary phases, each with distinct goals and activities to support healing and function.
Initial Healing Phase
During the first several days following surgery, your pet’s main focus is pain management and incision care. It’s important to administer all pain medications as prescribed and to keep an eye on the surgical site for any redness, swelling, or discharge. Some veterinarians may suggest adjunct therapies—such as moist heat applications to alleviate stiffness or physical modalities like laser therapy—to help reduce inflammation and support tissue repair.
Activity is typically restricted at this stage. Limit your pet’s movement by confining them to a small, comfortable area and allowing only short, leashed potty breaks. If your veterinarian approves, gentle passive range-of-motion exercises may be started, slowly moving the hip through its natural motion without causing discomfort. Always stop if your pet appears uncomfortable.
Rehabilitation and Strengthening Phase
About a week after surgery, as healing progresses, light activity is gradually reintroduced. The goal shifts to rebuilding muscle mass, regaining range of motion, and preventing the formation of stiff scar tissue in the new pseudo-joint. Recommended exercises may include slow, supported walks (flat surfaces at first, then gentle inclines or steps), controlled underwater walking if available, and activities that encourage deliberate weight-bearing on the operated leg—always avoiding any high-impact play or sudden twists.
Throughout the first month, it’s essential to prevent roughhousing or any activity that puts undue strain on the healing joint. Controlled, purposeful exercise helps optimize the functional outcome of the FHO.
Expectations for Recovery
Most pets return to regular activity around six weeks post-surgery, with those who had acute injuries often regaining mobility faster than animals with longstanding joint issues. Chronic conditions may require more time and patience as muscles rebuild and adapt.
If improvement is slow or your pet seems uncomfortable after six weeks, formal rehabilitation or a structured physical therapy program can offer additional support for a full return to function. Always consult with your veterinarian regarding the best post-operative plan for your pet’s specific needs.
Effect of Activity Level on FHO Outcomes
A dog’s activity level plays a significant role in recovering from femoral head ostectomy. Generally, dogs that are more active prior to surgery tend to bounce back faster and achieve better functional outcomes. This is largely due to their greater muscle mass, which helps support the hip joint and compensate for the absence of the femoral head and neck post-surgery.
In contrast, less active or sedentary dogs usually carry less muscle around the hip. This lack of muscle support may mean the joint takes longer to stabilize, potentially leading to a prolonged recovery period. Encouraging controlled exercise and strengthening activities both before and after surgery can help maximize post-operative results, regardless of a dog’s baseline activity level.
Troubleshooting Recovery: When Progress Stalls
If your dog isn’t regaining normal mobility or comfort within six weeks after FHO surgery, it may be time to seek additional help. Delayed or incomplete recovery—such as persistent limping, reluctance to use the leg, trouble rising, or ongoing discomfort—often benefits from more structured rehabilitation.
In these cases, discuss options with your veterinarian. Formal physical therapy programs can provide targeted exercises and therapies such as underwater treadmill sessions, laser therapy, or therapeutic ultrasound. Working with a certified canine rehabilitation therapist (CCRT) can make a significant difference for dogs needing extra support on the road to full function.
As always, consult your veterinarian promptly if your dog isn’t meeting expected milestones after an FHO. Early intervention can help maximize your pet’s mobility and comfort for the long term.
Activities to Avoid During Initial Recovery
During the first 30 days following FHO surgery, certain activities must be restricted to protect the healing joint and surrounding muscles. Activities that place undue stress on the hip, such as running, jumping, roughhousing, or quick directional changes, should be avoided. These actions can disrupt the formation of the pseudoarthrosis and delay recovery.
Instead, focus on gentle, controlled movements as recommended by your veterinary care team. Keeping your pet’s environment calm and minimizing opportunities for sudden activity is key to promoting a smooth and successful healing process.