What is a “Luxating Patella” in dogs?

Luxating patella is a common orthopaedic condition in pets. It is seen often in dogs and occasionally in cats. As a pet owner, discovering your beloved companion has been diagnosed with this issue can feel overwhelming. Understanding the condition, its causes, diagnosis, treatment options, and the importance of post-surgical care will help you navigate this journey confidently. Read on to get the full low down on this condition.

What Is a Luxating Patella?

The term “luxating patella” refers to the kneecap (patella) slipping out of its normal position in the groove of the thigh bone (femur). This can occur medially (towards the inside of the leg) or laterally (towards the outside of the leg). A luxating patella may affect one knee or both at the same time. The luxation is graded based on severity.

Grade I: The patella occasionally slips out of place but returns on its own.
Grade II: The patella slips out more frequently and may require manual manipulation to return.
Grade III: The patella is out of place most of the time but can be repositioned manually.
Grade IV: The patella is permanently dislocated and cannot be manually repositioned.

This condition can cause intermittent lameness, skipping steps, or an unusual gait. Owners will often describe their pet as ‘hopping’. This may seem harmless initially but these clinical signs can lead to arthritis and pain over time.

Causes of Luxating Patella

Several factors contribute to luxating patella:

Genetics

Small dog breeds such as Poodles, Yorkshire Terriers, and Chihuahuas are predisposed, though larger breeds can also be affected. In cats, it is believed to have a genetic component, particularly in certain breeds like Devon Rex and Abyssinian.

Congenital Deformities

Abnormal alignment of the bones in the leg can predispose the kneecap to luxate. Some pets may be born with structural abnormalities in the leg, such as shallow or malformed femoral grooves where the patella sits.

Trauma

Injury to the knee joint can lead to a luxating patella, even in pets without prior predispositions. This can include falls, jumping from high places, or accidents that damage the knee joint, leading to patellar luxation. Trauma can tear or weaken the ligaments or tendons that stabilize the kneecap.

Obesity

Excess weight places additional strain on the knee joint, increasing the likelihood of dislocation or worsening an existing condition.

Arthritis or Joint Disorders

Chronic joint inflammation can weaken the structures around the patella, contributing to instability. Joint disorders such as hip dysplasia can contribute to patellar luxation by disrupting the alignment or stability of the knee joint.

Diagnosing Luxating Patella

If your pet is showing signs of skipping steps, hopping on one leg, or intermittent lameness, ring your vet to arrange an appointment to get them checked out. Your vet will perform a thorough clinical examination. This will include:

Physical Manipulation

Your vet will gently palpate and manipulate your pet’s knee to feel for any swelling or abnormalities in the joint and assess the degree of luxation and determine the grade.

Gait Observation

Watching your pet walk or run helps identify any abnormalities in their movement.

X-rays

In more severe cases, X-rays may be necessary to evaluate the knee joint and surrounding bones for abnormalities or arthritis. Sometimes there are other issues with the knee joint such as cruciate ligament disease that need to be identified and addressed too.

Referral to a Specialist

If the diagnosis is complex or there are multiple issues present, your vet may recommend a consultation with an orthopaedic specialist.

Treatment

The treatment for luxating patella depends on the severity of the condition, your pet’s age, and the impact on their quality of life.

Non-Surgical Management

For mild cases (Grade I or II), your vet may recommend non-surgical approaches:

Weight Management

Keeping your pet at an ideal weight reduces strain on the joints.

Exercise Modification

Controlled, low-impact exercises (like swimming or gentle walks) can strengthen the surrounding muscles without overstressing the joint.

Physiotherapy

Tailored exercises designed to improve muscle strength and joint stability.

Pain Relief

Anti-inflammatory medications or joint supplements containing glucosamine and chondroitin may be prescribed.

While non-surgical management can be effective for lower-grade cases, progression to higher grades may necessitate surgical intervention.

Surgical Options

Surgery is the recommended treatment for moderate to severe cases (Grade III or IV) or when the condition significantly impacts the pet’s quality of life. There are several surgical techniques, and your vet will choose the most appropriate one based on the individual case:

Tibial Tuberosity Transposition

This procedure realigns the patellar ligament by repositioning the tibial tuberosity, the bony prominence where the ligament attaches. The bone segment is moved to a more appropriate position and secured, improving patellar tracking within the trochlear groove.

Trochlear Recession Sulcoplasty

To deepen the trochlear groove and provide better patellar stability, your vet may perform a sulcoplasty. Techniques such as wedge or block recession involve removing a section of cartilage and bone, then replacing it at a recessed level to create a deeper groove.

Soft Tissue Reconstruction

Adjustments to the soft tissues surrounding the patella may be necessary. This can include releasing tight tissues on one side of the patella and tightening loose tissues on the other to maintain proper alignment.

Femoral Osteotomy

In cases where there is significant bowing of the femur contributing to patellar luxation, corrective osteotomy may be performed. This involves cutting and realigning the femur to its proper orientation, often stabilized with plates and screws.

Combination Procedures

Often, a combination of the above techniques is used for the best outcome.

Surgery is typically highly successful, with most pets regaining normal function and comfort.

Post-Surgical Care

Post-operative care is crucial to ensure the success of the surgery and the long-term well-being of your pet. This phase requires commitment and patience from pet owners, as rehabilitation is a gradual process. Pets may be very lame for a while after the surgery and owners can find it difficult in the first few weeks. Their pet may seem to be less mobile initially but they will gradually start to improve.

Immediate Post-Surgery Period

Restricted Movement

Your pet will need strict rest for the first 4–6 weeks post-surgery. Confining them to a small, comfortable area is essential to prevent jumping, running, or climbing stairs. It is wise to separate them from other animals in the house so they are not tempted to play or fight and overexert themselves.

Pain Management

Your vet will provide pain relief medications and anti-inflammatories. Administer these exactly as prescribed to keep your pet comfortable.

Wound Care

Monitor the surgical site for any signs of redness, swelling, or discharge. Prevent your pet from licking the area by using a buster collar or a protective suit.

Follow-Up Appointments

Regular check-ups are essential to monitor healing progress and remove sutures if necessary. In some cases, x-rays may be necessary.

Rehabilitation Phase

After the initial rest period, a structured rehabilitation plan is usually introduced:

Controlled Exercise

Lead walks are gradually reintroduced, starting with short distances and increasing as advised by your vet.

Physiotherapy

Physiotherapy sessions may be recommended to improve joint mobility and strengthen muscles. Home exercises, such as gentle range-of-motion exercises, may also be beneficial.

Hydrotherapy

Swimming or underwater treadmill therapy can be beneficial as they provide low-impact exercise that strengthens muscles without stressing the joints.

Long-Term Management

Even after full recovery, ongoing care is essential to prevent recurrence or complications:

Maintain a Healthy Weight

It is very important that your pet maintains a healthy weight. Preventing obesity is crucial for reducing stress on the joints.

Regular Exercise

It is important to incorporate gentle low-impact activities to keep your pet fit and strengthen muscles.

Joint Supplements

Continue with supplements if recommended by your vet.

When to Contact Your Vet

During the recovery period, it’s vital to monitor your pet closely. Contact your vet immediately if you notice any of the following:

Reluctance to use the leg after the initial recovery phase.
Swelling or heat around the surgical site.
Discharge or bleeding from the surgical site.
Persistent or worsening pain despite medication.
Limping getting worse or changes in gait.
Lethargy/weakness
Going off food / not drinking.

Prompt action can help address any complications before they escalate.

Prognosis and Quality of Life

The prognosis for animals undergoing luxating patella surgery is generally favorable, particularly with timely intervention and appropriate post-operative care. Most dogs and cats experience significant improvement in limb function, with a reported success rate of 85–90% in mild to moderate cases. Severe cases with accompanying skeletal deformities may require more complex procedures, but outcomes are still positive with skilled surgical techniques.

Recurrence rates are low when surgery is performed correctly, but some animals, particularly those with severe deformities or advanced arthritis, may experience residual instability or mild lameness.

Factors Affecting Prognosis include:

The severity (grade) of the luxation before surgery.
Post-surgical complications, such as infections or implant failures, though these are uncommon.
Pre-existing arthritis, which may persist despite successful surgery.

Surgery typically alleviates pain and restores a more natural gait, enabling the animal to move comfortably. Pets are often able to return to regular activities, including running and playing, after the recovery period. Full recovery typically takes 8–12 weeks. During this time, activity should be restricted to prevent stress on the joint.

Preventing Luxating Patella

While not all cases are preventable, especially in predisposed breeds, there are steps you can take to reduce the risk:

Breed Awareness

If you’re considering getting a puppy, research the breed’s predisposition to luxating patella and choose a reputable breeder who tests their breeding dogs for genetic conditions.

Puppy Care

Avoid excessive jumping or high-impact activities during your puppy’s growth phase to protect developing joints.

Healthy Weight

Maintain your pet’s weight within the ideal range through a balanced diet and regular exercise.

Regular Vet Check-Ups

Routine visits to the vet can help detect early signs of joint issues.

Final Thoughts

As a pet owner, it’s natural to feel concerned when faced with a diagnosis of luxating patella. However, with proper veterinary care, most pets recover well and lead active, happy lives. By understanding the condition, exploring treatment options, and committing to post-surgical care, you can provide your pet with the best possible outcome.

If you suspect your pet may have a luxating patella or have questions about treatment and recovery, don’t hesitate to reach out to your veterinary team. They’re there to guide you every step of the way and will always be happy to help.

What is a “Luxating Patella” in dogs?