Luxation of the patella or patellar luxation, is a condition where the kneecap (patella) in dogs moves out of its normal position within the knee joint(the knee).
To get a clear picture of what patellar luxation is, let’s understand the anatomy of the knee and the role of the patella.
The patella is a small, flat, triangular bone located in front of the knee joint and its purpose is to protect the more fragile structures within the joint and assist in the transfer of forces during movement.
It is embedded in the tendon of the quadriceps muscle group that is responsible for extending the leg and when your dog moves about the patella glides up and down a groove at the lower end of the thigh bone (femur), allowing for smooth and efficient movement.
In a normal healthy dog, the patella stays within this groove as the leg moves, maintaining stability and proper alignment of the knee. However, in the case of a luxating patella, the patella shifts out of its groove.
Causes of patellar luxation
Several factors can contribute to the occurrence of a luxating patella:
Genetic Predisposition:
Small-breed dogs due to inherited anatomical abnormalities like a shallow groove in the femur or abnormal limb conformation have a higher chance of developing patellar luxation. Though it is less common it doesn’t mean that mixed & large breed dogs are immune to this condition.
Trauma:
Traumatic injuries can lead to the kneecap moving out of its usual position, causing patellar luxation. Sudden falls, collisions, overexertion or engaging excessively in high-impact activities or even sudden, forceful twisting or rotational movements of the leg can cause the patella to dislocate making it more prevalent in active & agile breeds that participate in athletic/ working activities
Obesity Muscle Weakness:
Excessive body weight and weak thigh muscles (quadriceps) or imbalanced muscle development around the knee can contribute to the patella’s misalignment. The patella relies on well-developed and balanced muscle strength to stay in its proper position during movement. Muscle weakening might happen due to the lack of exercise, aging, natural degeneration or poor nutrition especially during the growing years.
Ligament and Tendon Abnormalities:
If the ligaments and tendons that hold the patella in place are too loose, they may not be providing the joint with adequate support. If they are too tight, they might pull the patella out of its usual position.
Joint laxity:
Lax joints or loose joints make it easier for the patella to move out of its position. While some dog breeds are genetically predisposed to having loose joints, injury to soft tissues, and developmental abnormalities also result in a loose joint capsule.
Hormonal influences:
Hormonal imbalances, particularly those related to estrogen and testosterone, can affect the patellar ligament and tendon strength, potentially contributing to the development of patellar luxation.
Secondary to other orthopedic conditions:
Luxating patella can be secondary to other orthopedic issues, such as hip dysplasia or cruciate ligament injuries. The presence of these conditions may alter joint mechanics and lead to a patellar misalignment.
How severe is this condition?
In Patella Luxation the kneecap can move out of it’s place in two different directions.
Lateral Patellar Luxation:
When the patella moves towards the outside of the knee joint i.e. the kneecap dislocates or slips to the outer side of the femoral groove, which is the groove on the end of the thigh bone (femur) where the it is known as a lateral patellar luxation
Medial Patellar Luxation:
In the case of a medial patellar luxation, the patella moves towards the inside of the knee joint. This means that the kneecap dislocates or slips to the inner side of the femoral groove.
From here a luxating patella is classified into different grades based on its severity:
Grade I Patellar Luxation:
When the patella is luxated (moved) or dislocates but returns to its normal position when released it is a Grade I Patellar Luxation. There may not be any clinical signs or observable lameness, and the dog may only show occasional skipping or mild discomfort.
Grade II Patellar Luxation:
The patella spontaneously moves out of the femoral groove with normal movement and remains displaced until manually repositioned back. Lameness and intermittent skipping are more noticeable in Grade II patellar luxation.
Grade III Patellar Luxation:
The patella in this case is permanently displaced most of the time but can be manually placed back. Lameness is more pronounced in Grade III Patellar Luxation and the dog may show signs of discomfort and reluctance to bear weight on the affected leg.
Grade IV Patellar Luxation:
The patella is permanently luxated and cannot be manually repositioned into place. Grade IV Patellar Luxation is the most severe and most dogs may have severe lameness and difficulty using the affected leg.
How do I know if a luxating patella occurs? Symptoms and Clinical Presentation
The kind and severity of symptoms vary based on the grade of patellar luxation and your dog’s pain tolerance. Some dogs with mild luxation may exhibit only subtle signs, while others with a more severe luxation may show more pronounced symptoms.
While the luxation can occur in the front and hind legs- it is most commonly seen in the hind legs or the stifle joint which is very similar in function to the human knee joint. Here are some common signs to watch for:
Lameness and Skipping:
Lameness or a noticeable limp, especially after physical activity is one of the most common symptoms. They may also show an intermittent skipping motion while walking or running, which occurs when the patella temporarily dislocates and then returns to its normal position.
Difficulty or Reluctance to Bear Weight on the Affected Leg:
Dogs with patellar luxation may express difficulty in putting weight on the leg with the affected knee by avoiding that leg altogether or having a noticeable favour of one leg over the other
Pain and Swelling:
Patellar luxation also causes pain and discomfort causing your dog to yelp or even get aggressive when the knee is touched or manipulated. In some severe cases, this discomfort can be visible in the form of swelling around the affected area. it is also common for the affected area to be warmer than the rest of the body.
Bunny-hopping:
A bunny-hopping motion is commonly observed in dogs with joint issues. Bunny-hopping is when a dog uses both their hind legs simultaneously to move about instead of the usual alternating stride like a rabbit.
Extra Attention:
Dogs may give the joint extra attention and excessively lick or chew at the affected area to soothe the discomfort.
Do not wait for any significant clinical signs, if you suspect that your dog is experiencing discomfort or mobility issues, it is crucial to seek veterinary evaluation and diagnosis. Early detection allows for effective management of the condition that can greatly improve your furry friend’s quality of life.
Your Vet will probably perform a physical examination and might use imaging tools like X-rays, CT scans, or MRIs to accurately diagnose if your dog has a luxating patella
Mangaing Patellar luxation
Treatment options for luxating patella in dogs can vary depending on the severity of the condition and the individual dog’s specific needs. Here are some common approaches:
Grade I Patellar Luxation:
Grade I cases often don’t require surgical intervention, as the patella can manually be moved back into place and a conservative management route is often suggested which usually involves:
Weight Management and Exercise Regulation:
Maintaining a healthy weight is crucial for dogs with a luxating patella, as excess body weight can put additional stress on the affected joint. Your veterinarian may recommend a balanced diet and controlled exercise to manage weight and reduce strain on the joints.
Medications for Pain Relief and Inflammation:
Non-steroidal anti-inflammatory drugs (NSAIDs) or other pain medications may be prescribed to alleviate discomfort and reduce inflammation in the knee.
Physical Therapy and Strengthening Exercises:
Physical therapy, such as targeted exercises and controlled movement, can help strengthen the muscles around the knee, providing better support and stability. This can be particularly beneficial for dogs with mild to moderate patellar luxation.
Grade II Patellar Luxation
Some Grade II cases may be managed conservatively, but if lameness and discomfort are persistent, surgical treatments might be considered along with conservative measures.
Trochleoplasty is generally considered for a Grade II luxating patella it involves reshaping the groove on the femur where the patella rests in order to enhance the patella’s stability and reduce the risk of dislocation.
Grade III Patellar Luxation:
Grade III cases usually requires surgical intervention due to the frequent and more severe luxations.
Patellar luxation surgical treatments like, tibial tuberosity transposition may be performed where the attachment site of the patellar tendon on the tibia is realigned to improve joint mechanics. Trochleoplasty may also be performed.
Grade IV Patellar Luxation:
Grade IV cases almost always necessitate surgical treatment due to the permanent and severe displacement of the patella.
Surgery is required to realign the structures, reconstruct the joint, and stabilize the patella. Along with Tibial Tuberosity Transposition and Trochleoplasty, Medial Patellar Luxation (MPL) Surgery is also another surgical option that aims to correct the abnormal alignment of the knee joint and stabilize the patella in its proper position. The surgeon may deepen the femoral groove, release tight tissues, or tighten loose tissues to ensure the patella stays in place.
Femoral Varus Osteotomy (FVO) is another procedure used to correct patellar luxation and certain dysplasia conditions in dogs. It involves realigning the femur by angling it inward (varus) to improve joint stability and reduce pressure on the knee and hip joints. FVO is recommended for dogs with concurrent femoral deformities and patellar instability.
Rehabilitation and Post-operative Care:
After surgical intervention, rehabilitation is crucial to aid in the dog’s recovery and return to normal function. Rehabilitation programs may include controlled exercises, hydrotherapy, massage, and other modalities to improve muscle strength, joint mobility, and overall healing.
Regardless of the chosen treatment approach, regular follow-up visits with a veterinarian are essential to monitor your dog’s progress and adjust the treatment plan as needed. Treatment options should be discussed thoroughly with your veterinarian to determine the best course of action for your dog’s specific condition and overall health.
Surgical correction Vs. Conservative Treatment.
It’s essential to remember that the treatment approach for patellar luxation is not solely based on the grade but also takes into account the dog’s overall health, activity level, and any other concurrent orthopedic conditions. And even if the decision of surgical correction is opted for, adding conservative treatment methods into the mix can greatly improve the success of surgery and increase the rate of recovery.
But the real question lies in “how much does luxating patella surgery cost?” Surgical correction is suggested for more severe cases to restore normal alignment quickly and the costs do tend to be higher and can be greatly influenced by your location with cities being more expensive.
If the condition requires just conservative treatment, the cost is generally more reasonable and affordable but with the duration of the treatment being longer- the costs can add up.
What is the prognosis?
If surgery is performed before the development of arthritis or another knee injury, the prognosis is usually very good allowing your dog to regain full use of their leg. However, if in case arthritis has already developed in the knee joint, your dog may experience intermittent pain in the leg and it may progress even after surgery.
That said, patellar luxation surgery doesn’t guarantee that the luxation won’t happen again. Prescription anti-inflammatories, joint supplements, and the diet may slow the progression of arthritis and help control any discomfort. Weight reduction is also recommended for overweight dogs.
Post-operative physiotherapy may be recommended. Your veterinarian can help you determine the best post-operative plan for your dog.
Can a luxating patella cause long-term problems?
This completely depends on the severity of the higher the grade the more likely your dog will develop long-term problems, especially if more than one limb is affected.
In some cases of Grade I patellar luxation, many dogs live with the condition for many years, sometimes, for their entire lives, usually undetected; however, as they get older, arthritis develops and it results not only in decreased mobility but joint pain as well. Once your dog develops arthritis, it cannot be reversed.
Patellar luxation also makes your dog prone to other orthopedic abnormalities and injuries, the most common being a torn cranial cruciate ligament.
Preventative Care
While kneecap pops are inevitable in some cases, being a responsible pet parent along with regular veterinary care and appropriate preventive measures can significantly reduce the risk and promote the overall well-being of your furry companion.
Select a Responsible Breeder:
If you are considering getting a dog, choose a reputable and responsible breeder who prioritizes the health and genetic screening of their breeding dogs. Especially when you are considering miniature breed dogs or giant breed dogs. Responsible breeding can help reduce the risk of passing on genetic predispositions to patellar luxation.
Regular Veterinary Check-ups:
Schedule regular check-ups with your veterinarian to monitor your dog’s overall health, including their musculoskeletal system. Especially if your dogs breed is predisposed to developing a luxating patella. Early detection of any orthopedic issues, including patellar instability, can lead to a successful intervention.
Balanced Nutrition:
Feed your dog a balanced and age-appropriate diet to support their overall health. Adequate nutrition is essential for maintaining healthy bones, muscles, and joint structures. Don’t shy away from supplements when needed. It is hard to get a completely balanced diet especially if you have a pup that needs some extra support.
Controlled Exercise:
Engage in controlled and appropriate exercise for your dog and avoid excessive high-impact activities, especially during their growth phase to avoid undue stress on your dogs joints.
Weight Management:
Keep your dog at a healthy weight to reduce stress on their joints. Obesity can exacerbate orthopedic conditions and increase the risk of patellar luxation while also slowing down recovery time.
Strengthening Exercises:
Incorporate low-impact strengthening exercises into your dog’s routine, under the guidance of a veterinary professional. This will greatly help strengthen any weak muscles or loose tissues around the knee and provide support and stability.
Be Vigilant:
Keep an eye out for any changes in your dog’s gait or behavior, as early detection of lameness or mobility issues can lead to prompt veterinary evaluation and management.
Living Dogs affected with a Luxating Patella
Here’s a few additional things you can do to help your dog’s luxating patella and make life a little more comfortable and easier for them!
Environmental Modifications:
Provide Comfortable Resting Areas:
Offer soft, supportive bedding to alleviate pressure on joints and encourage restful sleep. Invest in an orthopedic bed, your dog will thank you for it as the thick memory foam curves with your dogs body. It also helps keep your dog warm which helps in pain relief for some dogs.
Home Modifications:
Minimize potential hazards like stairs and create an easily accessible environment with ramps to help your dog navigate elevated surfaces. You can also have their food and water bowls placed nearer to avoid excessive movement. Placing their bedding on a low surface is also a good idea as it can help them get on and off easier.
Non-Slip Surfaces:
Use non-slip mats, toe grips or rugs to prevent your dog from slipping on smooth floors and injuring themselves.
Safe Play and Exercise:
Engage in low-impact exercises and playtime that won’t exacerbate the condition. Short, frequent walks on an even surface is preferred over strenuous activities.
Even if your dog is put on strict crate rest- ensure you still provide some mental enrichment like a fun puzzle or chew toy!
Rehabilitation and Physical Therapy:
Consult a Professional:
Seek guidance from a veterinary rehabilitation therapist who can help design a personalized rehabilitation plan for your dog. Ask them to train you in some basic strengthening exercises and massages that you can carry out at home. Adding a few home sessions will help your dog relax and improve blood circulation.
Hydrotherapy:
Hydrotherapy is when your dog is placed in a controlled pool or underwater treadmill which makes your dog more buoyant. This takes off the pressure on your dogs joints and provides low-impact exercise to improve joint mobility. The water also provides gentle resistance that can further help build and strengthen muscle.
Understanding Patellar Luxation in dogs is essential for promoting their well-being and ensuring a good quality of life.
By gaining a comprehensive understanding of luxating patella in dogs and taking proactive measures, we can ensure that our beloved canine companions live happy, healthy, and fulfilling lives, even in the face of this orthopedic challenge.