Patellar Luxation

Description: Luxating patella or floating kneecap occurs when the kneecap (patella) moves around or displaces in and out of place, which can cause lameness. Smaller breeds are more prone to patellar luxation and it may be influenced by genetics. Typically, the dog will be running and playing normally, when suddenly his leg is lame. He may yelp or cry at the occurrence, holding the leg off the ground. Just as suddenly, he continues using his leg and running around normally. In this scenario, the kneecap popped out of place, causing the dog to raise its leg and limp, but as soon as the kneecap went back into place, he was able to put his foot back down and use it normally.
Kneecaps function properly with patella ridges that keep it in its proper place. However, some dog breeds have flat ridges, which means the kneecap can pop out of place more easily.

There are four grades to describe luxating patella, with Grade 1 being the mildest and Grade 4 being the most severe.
Grade 1 is when the kneecap pops out of place but also pops back in.
Grade 2 describes a kneecap that pops out but doesn't always pop back in and may require manual manipulation to pop it back into place.
Grade 3 is when the kneecap is out of position most of the time and can be manually placed back into position, but it doesn't always stay.
Grade 4, the most severe form of luxating patella, is when the kneecap is never properly in place, and will not stay even when manipulated.

While the movement of the kneecap often happens quickly and appears painless, the movement can cause a quick jolt of pain each time this happens. With repeated occurrences, the cartilage can wear down, leading to bone-on-bone contact and more pain for the dog.

Symptoms: A sudden yelp while running, limping, lameness, refusal to put weight on the leg. You may notice this happening occasionally, with limping and refusal to bear weight on the affected leg, followed by regular walking and running.

Treatment: If your dog has Grade 1 patellar luxation, it is important to be proactive. Be sure that your dog is at a healthy weight because extra weight can cause more stress on the joint. Continue to exercise your dog because maintaining good muscle tone will help to keep the kneecap in place. Other recommendations are oral joint supplements and feeding an anti-inflammatory diet, both of which you should discuss with your veterinarian.
Luxating patella, if left untreated or more severe, can cause the grooves in the bones to gradually wear down, leading to more frequent occurrences and pain, and possible arthritis. Severe patellar luxation is typically treated with surgery. The femur may undergo trochlear modification in which the groove is restructured to better contain the kneecap. The kneecap may be tied down to prevent deviation in the future in a procedure called lateral imbrication.

Example claim:

Total claim amount: $3,205.95
Deductible applied: $0.00
10% co-insurance: -$320.59
Trupanion repaid: $2,885.36

Cost: $600-$2,000+

Breeds prone to Patellar Luxation include: