Luxating patella is a condition that occurs when the kneecap slides out of place, getting dislocated from the joint. Each time the kneecap slides out of place, the cartilage becomes increasingly more damaged. If the problem persists and does not receive veterinary care, the damage causes excruciating pain and eventually triggers osteoarthritis. While it occurs most frequently in smaller dog breeds, cats and larger dogs are still susceptible. Luxating patella can be an acquired condition or can exist at birth. Most cases are believed to be genetic so pets with confirmed instances of luxating patella are encouraged to not be used for breeding.

Any pet with a suspected luxating patella should undergo weight management and light exercise to prevent obesity as excess weight can cause increased pressure on joints, worsening an existing condition. The symptoms a pet exhibits will vary depending on their particular level of pain tolerance; some pets might simply freeze in place until the kneecap moves back into position, while others may vocally express their pain.

Symptoms of luxating patella: 

• Extending one leg for a period of time prior to quick movements. 
• Favoring a particular limb. 
• Hesitant to jump up on things or move hastily. 
• Shaking of a particular leg. 
• “Skipping” (running while holding one leg off the ground). 
• Sudden lameness in a limb with quick recovery. 
• Temporary paralysis of one or multiple legs.

Diagnosing luxating patella

During your pet’s exam the veterinarian can often determine a luxating patella simply through manually manipulating the kneecap. Depending on the severity of pain and based on the symptoms you describe your pet experiencing, sedation might be necessary for the vet to fully manipulate the kneecap and perform this diagnosis. In some cases, supplementary X-rays might also be recommended to visualize the joint and help with treatment or surgical planning.

In an effort to prevent further damage to joints, pet owners should never manipulate the kneecap or joints on their own. Doing so could worsen their pet’s suffering and cause additional harm to cartilage.

Classifications of luxating patella

There are four different classifications that veterinarians use to judge the gravity of a pet’s luxating patella. The system ranks pets’ symptoms with numbers ranging from 1 to 4 with 1 being the least severe and 4 being the most severe. The following is a list of each pain level and what the number signifies: 

1. Kneecap can be manually popped out of place, or can pop out on its own. Pops back into place on its own. 
2. Kneecap pops out on its own, but occasionally needs to be manually popped back into place. 
3. Kneecap sits outside of groove a majority of the time, but can be manually popped back into place. However, it will not stay in place very long. 
4. Kneecap sits outside of groove entirely. Cannot be manually popped back into place.

How is luxating patella treated?

After properly determining the severity of your pet’s luxating patella, the veterinarian will discuss the various methods of treatment available. There are both surgical and non-surgical methods of treatment. Often, pet owners who opt against surgery find that their pet’s condition worsens and must eventually undergo surgery to fix the problem.

Non-surgical treatment involves managing pain by administering anti-inflammatories (non-steroid), which helps lessen discomfort and reduce inflammation. Along with a medicated diet, exercise, and a physical therapy routine, pet’s that have type 1 or type 2 luxating patella often find that this method of pain management helps strengthen the quadriceps muscles and provides relief from pain.

There are several surgical methods that can help alleviate pain. The most common procedures involve one of the following: reconstructing the soft tissues surrounding the knee joint which helps support the kneecap; deepening the groove in the femur bone that the kneecap rests within; or securing the kneecap to the outside of the bone to prevent it from sliding. If you opt for a surgical treatment for your pet, the veterinarian will further discuss the various options and will review which method is best for your pet’s particular case. As with most severe conditions, with more acute cases of luxating patella, surgery is the preferred method of treatment.

If you notice any questionable symptoms in your pet, contact our office as soon as possible to schedule an exam.