Patella luxation in dogs

Dog laying on sofa with owner

Patella luxation is a health condition that can affect a dog’s knees. There isn’t one single cause but instead is due to a combination of genetics and lifestyle. Find out more about patella luxation, including what it is, signs to watch out for, how to have your dog diagnosed and how it’s treated.

What is patella luxation?

Patella luxation, or a luxating patella, is a disease that causes the kneecap, known as the patella, to pop out from the groove it sits in. A dog’s kneecap sits on top of their leg bone (just like ours) but they can sometimes become displaced, with some dogs affected more severely than others.

What causes patella luxation?

Patella luxation often begins when a dog is young. Some dogs are more prone to patella luxation (certain breeds and dogs of a particular shape). Because of the similarities in typically affected dogs, scientists believe that a dog’s genetics may play a role in their risk of developing patella luxation. When some puppies grow, their back legs don’t develop quite as they should (i.e., the leg bones move the patellar towards the inside of the knee joint). This can lead to a cascade of issues that can cause problems with their muscles, leg bone and shin bone, making the problems with their patella worse.

What are the symptoms of patella luxation?

When the patella dislocates from its normal groove, the knee is unable to properly extend, affecting how a dog walks. This abnormal gait is often described as ‘skipping’ or ‘bunny-hopping’. It can happen occasionally (i.e. just for a few steps and then disappear) or, in more severely affected dogs, it may be continuous. The patellae are only found in the back legs, which means that dogs can’t develop this issue in their front limbs. Some dogs, particularly older ones, may also have a stiff gait from arthritis. This can be caused by wear around the cartilage from the patella popping in and out.

Is patella luxation genetic?

Genetics are likely to play a part in a dog’s risk of developing patella luxation (it’s seen more often in smaller dogs, with some breeds being more prone than others). This condition is a complex inherited disorder, which means that there are a number of factors involved in a dog’s risk, such as lifestyle (i.e. exercise and weight) and several different genes, all interacting to determine risk.

How common is patella luxation?

Patella luxation is a fairly common condition, affecting approximately 1.3% of the dog population. It’s more commonly seen in smaller dogs, but larger dogs can be affected too. It’s worth all dog owners knowing the signs to watch out for.
Some breeds affected by patella luxation include:

Is patella luxation painful?

It’s difficult to know whether patella luxation is painful in dogs, as some dogs can be very good at hiding pain. It’s likely that it’s uncomfortable when their patella slips, and for dogs with severe disease, this may even be painful. Over time, as the patella continues to displace, the surrounding tissues and cartilage may wear away, which can cause arthritis. Arthritis can be painful, and affected dogs may need pain medication and anti-inflammatories to help ease their symptoms.

Can I physically put my dog’s luxating patella back in?

For most dogs with patella luxation, the patella will temporarily pop out and go back in after a few steps. If it becomes permanently dislocated, you’ll need to take your dog urgently to the vet. Trying to put the patella back into place could be very painful for your dog or may cause more damage to the surrounding tissues.

What can I do to prevent patella luxation?

Researchers believe that patella luxation is influenced by a number of different factors, which makes it difficult for you to do just one thing to prevent this disorder. As genetics are thought to be involved, if you are buying a puppy from a breed known to be predisposed, it’s important to ask your breeder if the parents have ever shown symptoms or been diagnosed. It’s also worth asking if this condition has been seen in the puppy’s mother’s or father’s pedigree. If you’re considering breeding your dog, we don’t recommend you breed from a dog affected by patella luxation, as it’s possible the genes associated with the disease could be passed on to the puppies.

If you’ve already brought your puppy home, appropriate exercise and nutrition will give your dog the best chance of developing properly, although this may not be enough to keep patella luxation at bay.

How is patella luxation diagnosed?

The symptoms described earlier are a strong suggestion that your dog may be affected by patella luxation, so you should take your dog to the vet if you see them limping, hopping, or moving abnormally. Your vet will undertake a physical assessment and usually will look at how easily the patella can be moved manually out of its groove. Your dog may then be referred to a specialist orthopaedic vet depending on the severity of their disease.

Depending on the advice from your vet, your dog may need to undergo further investigation to see how severe their disease is. This may include an x-ray, CT scan or MRI scan, which will need to be performed under sedation or general anaesthetic.

Is there a grading or screening scheme for patella luxation?

Some vets will grade your dog using a system called the Putnam scheme. This grades dogs from 0 to 4, rating how severe their patella luxation is; 0 is normal and 4 is a permanent luxation and severe disease.  

Unfortunately, at the moment we don’t record results from dogs that have been graded for patella luxation, and there is no formal scheme for us to accept results at this time. Many Breed Clubs run their own grading schemes for patella luxation. If you wish to get your dog graded, you could contact your local breed club for further information.  

How do you treat patella luxation?

Unfortunately, patella luxation does not go away on its own. This is a lifelong condition that may progress as your dog ages.

Treatment depends on how severe your dog’s patella luxation is. If your dog is only slightly affected, your vet may recommend you keep an eye on it and see how or if this progresses over time (watching out for any pain or worsening in symptoms). Other advice might include losing weight to minimise the amount of stress being put on your dog’s patellae, physiotherapy, hydrotherapy, prescribing painkillers or anti-inflammatories, or changing the amount and type of exercise you give your dog.

If your dog is more seriously affected, they may be recommended to undergo surgery to correct the bone malformations and bring the bones and tissues into a healthier construction. There are several different types of surgery that could be chosen, these are listed below.

Femoral varus osteotomy

This surgery involves reshaping the femur bone to straighten it and allow the patella to sit correctly and in line with the femur. The femur bone will be cut and then straightened using a specialised plate and screws.

Recession sulcoplasty

This procedure involves deepening the groove that the patella sits within and is used for dogs that have a particularly shallow groove on their femur. The groove is deepened by taking away excess cartilage and bone so that the patella can sit snugly and is less likely to pop out.

Soft tissue reconstruction

This procedure focuses on tightening up the tissues that sit around the patella, as these often become lax over time from inappropriate movement. There may be other tissues that are too tight and require loosening to allow the joint to work properly.

Tibial tuberosity transposition

This type of surgery looks at correcting how the tendon that sits across the patella and tibia (shin bone) is positioned. This is mostly done by cutting the bone where the tendon attaches, moving it so that the tendon sits properly. This procedure is often undertaken using wire and pins to fix the muscles and bone into place.  

In some dogs, a combination of techniques will be used. It’s important to discuss these options with your vet or specialist before your dog undergoes surgery so that you fully understand how long your dog will take to recover. The expense of these will differ depending on your vet and insurance cover, so you should enquire about this at the beginning of your dog’s treatment to be fully aware of the costs involved.

Can a dog live with patella luxation?

Many dogs with patella luxation can live with a good quality of life, but it does depend on the severity of their disease, and whether they have any secondary conditions, such as arthritis. Using veterinary prescribed painkillers and anti-inflammatory medications, as well as lifestyle changes, may give your dog a better quality of life, but it’s worth speaking to your vet about managing this condition.

Where can I find further support and resources?

Your vet is the best first point of call for further support on this condition and your dog’s individual journey for living with patella luxation.

You may also find it useful to seek advice from owners who have had similar experiences; we would recommend contacting your breed club or Breed Health Co-ordinator, as they may be able to share their knowledge with you and put you in touch with other owners who have had dogs affected by the condition.

Can I contribute to any research?

It’s worth checking our research page to see current research projects that apply to your breed and how to get involved.

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We are not a veterinary organisation and so we can't give veterinary advice, but if you're worried about any of the issues raised in this article, please contact your local vet practice for further information