Alice White
In the case of patellar luxation, to put it casually, the kneecap pops out. There is a characteristic gait pattern in dogs when this happens. If animals are affected by the patellar luxation, their lower and upper thigh bones are shaped in such a way that their straight patellar ligament does not run centrally over the groove provided for this purpose. And of course not the kneecap either.
The knee joint is stretched by large muscles. The muscles originate on the thigh and pelvic bones. They run along the front of the thigh and then meet in a common tendon just above the knee joint. The tendon is known as the straight patellar ligament or patellar tendon. The tendon runs in front over the knee joint to the lower leg and starts directly below the knee joint. The kneecap is embedded in this ligament. The kneecap runs like a groove. If it leaves its central position, the affected dog is called a patellar luxation: the kneecap pops out. As a result, the stretching mechanism can no longer function properly.
Luxating Patella
- The kneecap can jump out inwards or outwards;
- Inward, it jumps out more often;
- Sometimes a dislocation only occurs every now and then. It can even be an incidental finding by the veterinarian;
- There are four degrees of patellar dislocation.
How Does a Patellar Dislocation Show?
There is a very typical lameness for the kneecap jumping out. The dog runs normally, suddenly the affected leg is noticeable for one or two steps, then the dog continues walking normally. This “hopping” is often seen as funny by pet owners and completely misinterpreted. It’s a classic symptom of patellar dislocation. If a keeper notices this, he should take his dog to a veterinarian as soon as possible.
Are There Dogs That Are Particularly Vulnerable?
Mostly small dogs and dwarf breeds suffer from patellar luxation. In the meantime, however, several medium-sized and larger dog breeds are also affected. In them, the dislocation tends to take place on the outside, while in the small breeds the dislocation takes place on the inside. There has been evidence for many years that patellar dislocation is a common inheritance.
The dislocation is not equally pronounced in all breeds, but there are many cases, especially in the Miniature Poodle, Yorkshire Terrier, Chihuahua, or Pekingese.
When Should the Dog Go to the Vet?
If it is noticeable several times when going for a walk that the dog is completely relieving the leg, it should see the vet as soon as possible. If a patellar dislocation is not treated, it does not immediately result in osteoarthritis, but it does damage the cartilage. The incorrect posture can also lead to a cruciate ligament tear. The veterinarian can divide the dislocation into four degrees.
- No dislocation corresponds to grade 1. The dog would then be approved for breeding. In grade 1, the kneecap spontaneously returns to its normal position. There is hardly any lameness here.
- For grades 1 or 2, physiotherapy can help. The kneecap stays in place through directed muscle pull. In most cases, there is little osteoarthritis formation, but the cartilage between the patella and thigh will be removed if the patellar dislocation has not been treated for years. This cannot be remedied even with an operation.
- Grade 2 and 3 are fluent and sometimes difficult to distinguish. In both cases, the kneecap is often not in the groove, the displacement of the kneecap is permanent. The dogs cannot transfer the force and take the strain off the leg.
- A dog usually shows grades 2 to 4 clearly. As a rule, an operation must follow here.
- In grade 4 it is no longer possible to push the patella back out of the dislocation. This can be overlooked if the dogs are running fairly steadily for months to years. Until they finally develop massive osteoarthritis.
What Treatment Options Are There?
The safest and pretty much the only option, in this case, is surgery. The patella is brought into the correct position and fixed. The bones are prepared accordingly so that the patella stays in place permanently. If the cartilage is already very badly damaged, a half-prosthesis can be used. This is an expensive operation. The standard operation to correct the dislocation is around $1000. For the half-prosthesis, you have to dig deeper into your pocket. Preventing a patellar luxation is actually not possible. Targeted muscle training could stabilize the kneecap in young dogs, but this has no effect in the long term.
The patellar luxation is passed on genetically. The only effective prevention would be breeding with patellar luxation-free dogs.
In the case of small dogs, in particular, interested parties should have their parents’ papers shown whether they have certificates of patellar luxation-free. If, moreover, more breeders would consistently ensure that dogs are only bred that is not pre-stressed, the problem can be resolved. In most cases, treatment is only possible surgically. The prognosis for this is good. Those who do not have animal health insurance have to bear the costs themselves.
