Patellar Luxation Surgery

Bottom Line

Patellar luxation surgery helps correct a "slipped kneecap" in dogs and cats, a common orthopedic issue where the patella dislocates from its normal groove, causing pain and lameness. This procedure aims to realign the knee structures, prevent future dislocations, and improve your pet's comfort and mobility, often leading to excellent long-term outcomes.

What the procedure involves

Patellar luxation surgery is a specialized orthopedic procedure designed to stabilize your pet's kneecap (patella), ensuring it glides smoothly within its natural groove.

Your pet's knee joint, also known as the stifle joint, is a complex structure. The patella is a small bone embedded within the quadriceps tendon, which connects the large thigh muscles to the shin bone (tibia). Normally, the patella sits snugly in a V-shaped groove on the end of the thigh bone (femur), called the trochlear groove. When your pet moves their leg, the patella acts like a pulley, helping to extend the knee. However, in patellar luxation, this kneecap repeatedly or permanently slips out of this groove, either to the inside (medial luxation) or outside (lateral luxation) of the leg. This can be painful and lead to a distinctive "skipping" gait or persistent lameness.

The underlying cause of patellar luxation is often a developmental misalignment of the entire limb, not just an isolated knee issue. "Patellar luxation is often associated with multiple deformities of the hindlimb, involving the hip joint, femur, and tibia," explains the Merck Veterinary Manual. To correct this, your board-certified veterinary surgeon will typically employ a combination of techniques tailored to your pet’s specific anatomy and the severity of the luxation. The primary goals are to deepen the trochlear groove, realign the patella, and balance the soft tissues around the knee.

One common technique is trochlear groove deepening (trochleoplasty). This involves carefully reshaping the V-shaped groove on the femur, making it deeper so the patella has a more secure track to glide in. Another crucial step is tibial tuberosity transposition (TTT). The tibial tuberosity is a bony bump on the shin bone where the patellar tendon attaches. If this bump is out of alignment, it pulls the kneecap sideways. During TTT, the surgeon carefully cuts this bony attachment, moves it to the correct position, and reattaches it with pins or wires, thereby realigning the entire quadriceps mechanism. Additionally, soft tissue adjustments are often made, such as releasing tight tissues on one side and tightening them on the other to help hold the kneecap in place. In very severe cases with significant bone deformities, a corrective osteotomy might be necessary, involving cutting and realigning sections of the femur or tibia. The combination of these techniques ensures the kneecap tracks correctly, reducing pain and preventing future luxations.

When this surgery is recommended

Surgery for patellar luxation is typically recommended when your pet experiences persistent lameness, pain, or when the condition is severe enough to cause significant functional impairment or progressive joint damage.

While patellar luxation is a common condition, affecting about 7% of puppies, not all cases require surgery. Your veterinarian will assess the severity of the luxation using a grading system from Grade 1 (mildest) to Grade 4 (most severe), alongside a thorough orthopedic examination and X-rays. For pets with very mild, intermittent luxation (Grade 1) that rarely causes symptoms, or for pets that are older and less active, conservative management is often the first approach. This might include weight management, controlled exercise, anti-inflammatory medications, and physical therapy. The goal here is to manage comfort and prevent progression, rather than correct the anatomical defect. However, it's important to understand that "conservative treatment... does not correct the underlying anatomical abnormalities, so progression of the luxation can still occur over time," as noted by the Merck Veterinary Manual.

Surgical intervention becomes the primary recommendation for pets with Grade 2, 3, or 4 luxation, or any grade where the pet is experiencing significant clinical signs such as frequent skipping, persistent lameness, pain, or progressive worsening. "Surgical intervention is typically recommended for dogs with moderate to severe patellar luxation (grades 2–4), dogs experiencing marked lameness, or dogs with progressive worsening of clinical signs," states the Merck Veterinary Manual. Early surgical correction, particularly in younger animals with higher-grade luxations, can help prevent long-term complications like severe osteoarthritis and rupture of the cranial cruciate ligament.

Decision factors for surgery also include your pet's age, breed, overall health, and your family's lifestyle. For instance, an active young dog with a Grade 2 luxation might be a strong candidate for surgery to ensure a full, active life, whereas a sedentary older cat with the same grade might be managed conservatively. Your board-certified veterinary surgeon will discuss these factors with you, outlining the potential benefits and risks, to help you make the best informed decision for your beloved companion.

What it costs in the United States

The cost of patellar luxation surgery in the United States typically ranges from $2,500 to $5,500 per knee, reflecting the specialized nature of the procedure and comprehensive care involved.

This range is a national average and can vary significantly based on several factors. Geographic location plays a role, with clinics in metropolitan areas or regions with higher costs of living generally having higher prices. The specific veterinary practice, whether it's a general practice with orthopedic capabilities or a specialist orthopedic surgery center, can also influence the fee. The complexity of your pet's individual case is a major driver of cost. For example, a straightforward Grade 2 luxation might fall on the lower end, while a severe Grade 4 luxation requiring multiple bone-reshaping procedures or repair of concurrent issues will be at the higher end. The need for advanced imaging like CT scans, the type of anesthesia, and the duration of hospitalization can also add to the overall expense.

The quoted price typically includes the surgeon's fees, anesthesia, surgical supplies, post-operative medications, and initial follow-up appointments. However, it's crucial to clarify with your veterinary surgeon's office what exactly is covered in their estimate. Additional costs might include pre-surgical blood work, extended hospitalization, physical therapy or rehabilitation sessions, and any potential complications that may arise.

Risks and contraindications

While patellar luxation surgery is generally safe and highly effective, like any surgical procedure, it carries potential risks and is not suitable for all patients.

Your veterinary surgeon will thoroughly evaluate your pet to determine if they are a good candidate for the procedure. Common surgical risks include those associated with general anesthesia, such as adverse reactions to medications, and post-operative complications like infection, seroma formation (fluid accumulation under the skin), or implant failure if pins or wires are used. Although rare, nerve damage or persistent lameness can also occur. In some cases, despite successful surgery, the patella may re-luxate, necessitating further intervention. This risk is generally lower with experienced board-certified surgeons.

Certain conditions and circumstances are considered contraindications, meaning the surgery should ideally not be performed or requires significant modification:

• Skeletally immature puppies under 9 months: Procedures involving bone cuts and realignment can interfere with normal bone development before growth plates have closed.
• Asymptomatic Grade I luxation: For pets with very mild luxation that causes no pain or functional issues, the risks and recovery associated with surgery typically outweigh the potential benefits. Conservative management is preferred.
• Significant concurrent cruciate ligament disease: If a substantial tear is already present, it complicates knee stability. A combined or staged approach might be required, as a standalone patellar luxation repair might not fully resolve the lameness.
• Active joint infection: Performing elective surgery on a joint with an active infection can spread the infection, severely compromising the outcome and increasing the risk of serious complications. The infection must be resolved first.

Your veterinary surgeon will conduct a comprehensive physical exam, blood tests, and imaging to identify any potential risks or contraindications before recommending surgery.

Recovery

Recovery from patellar luxation surgery requires a dedicated owner and a carefully managed, multi-week rehabilitation plan to ensure optimal healing and a return to full mobility for your pet.

The initial post-operative period is crucial for pain management and protecting the surgical site. Your pet will likely receive pain medication and anti-inflammatories, and their activity will be severely restricted.

What does the immediate post-operative period look like (Week 1-2)?

For the first one to two weeks, your pet's activity will be highly restricted. This typically means strict crate rest or confinement to a small room, with only leash-controlled outings for bathroom breaks. No running, jumping, stairs, or rough play are allowed. The incision site must be kept clean and dry, and you'll need to monitor for any signs of infection, swelling, or discharge. An Elizabethan collar (cone) will likely be necessary to prevent your pet from licking or chewing at the stitches. Your veterinarian will typically recheck the incision and general healing around 10-14 days post-op, often removing stitches at this time.

How does activity slowly increase (Week 3-6)?

Following the initial two weeks, your veterinarian will guide a gradual increase in activity. This usually involves short, controlled leash walks (5-10 minutes, 3-4 times a day) on flat, non-slip surfaces. The duration and intensity of these walks will slowly increase over the following weeks. Physical therapy, which might include passive range of motion exercises or gentle massage, may be introduced to help improve joint flexibility and muscle strength. It’s vital to continue avoiding strenuous activities and maintain leash control to prevent accidental injury or re-luxation.

What about long-term rehabilitation and return to full activity (Week 7-12+)?

By week 7-8, many pets are making good progress, and rehabilitation exercises will become more structured. This could involve inclined walks, specific strengthening exercises, or even hydrotherapy (under veterinary guidance). The goal is to rebuild muscle mass and restore normal limb function. Full return to unrestricted activity, such as running, jumping, and playing with other dogs, typically takes 10-12 weeks, or even longer for more severe cases or larger breeds. "Mild or moderately affected dogs generally recover fully," according to the Merck Veterinary Manual's pet owner version. It's important to remember that every pet heals at their own pace, and consistent communication with your veterinary surgeon and rehabilitation specialist is key.

When to seek emergency care

While diligent post-operative care can prevent many complications, it's vital to recognize signs that warrant immediate veterinary attention, as prompt action can prevent serious issues.

After your pet's patellar luxation surgery, monitor them closely for any changes in behavior or physical condition. Contact your veterinary surgeon immediately if you observe any of the following:

• Severe or sudden increase in pain (any time post-op): If your pet is crying out, panting heavily, or refusing to bear any weight, it could indicate a complication.
• Non-weight bearing lameness that suddenly worsens after initial improvement (any time post-op): A sudden decline in limb use, especially after seeming to improve, could suggest re-injury or a problem with the surgical repair.
• Excessive swelling, redness, heat, or pus-like discharge from the incision site (within first few days/weeks): These are signs of a potential infection or seroma requiring immediate assessment.
• Incision opens or stitches come out (within first 2 weeks): If the surgical incision separates, the wound is compromised and needs immediate attention.
• Persistent fever (any time post-op): A fever (typically over 103°F) can be a sign of systemic infection.
• Loss of appetite, lethargy, or persistent vomiting (any time post-op): These generalized signs of illness could indicate a reaction to medication, an infection, or another underlying problem.

Always err on the side of caution. If you are concerned about any aspect of your pet's recovery, a quick phone call to your veterinary team can provide peace of mind or prompt necessary intervention.

How to find a specialist

Finding a board-certified veterinary orthopedic surgeon is crucial for the best possible outcome for your pet's patellar luxation surgery, as their specialized training ensures expert care.

Just like in human medicine, veterinary specialists undergo extensive additional training beyond their general veterinary degree. A board-certified veterinary surgeon has completed a demanding residency program (typically 3-4 years) in surgery, followed by a rigorous examination process to achieve diplomate status with the American College of Veterinary Surgeons (ACVS). This certification signifies a deep level of expertise in complex surgical procedures, including those for orthopedic conditions like patellar luxation.

When seeking a specialist, start by asking your primary care veterinarian for a referral. They often have established relationships with local specialists and can provide recommendations. You can also utilize online directories. The American College of Veterinary Surgeons (ACVS) website (acvs.org) offers a "Find a Veterinary Surgeon" tool, allowing you to search for board-certified specialists in your area. This ensures you are connecting with a veterinarian who has met the highest standards of surgical excellence.

When you've identified potential specialists, consider asking them a few key questions during your consultation:

• How many patellar luxation surgeries do you perform each year?
• What specific surgical techniques do you recommend for my pet's case, and why?
• What is your success rate for this procedure?
• What does the full estimated cost include, and what might be additional?
• What kind of post-operative care and rehabilitation do you recommend or provide?

Choosing a board-certified specialist offers peace of mind, knowing your pet is in the hands of someone with advanced knowledge, skill, and access to state-of-the-art equipment for the best possible care.

Looking for a specific clinic? Browse our directory of specialist veterinary practices.