Many dog-owning families may have heard of patellar luxation. When a dog is affected, it can cause their owners to worry. Some dogs lift their legs while walking, while others cry out in pain when held. Patellar luxation is a common problem in small breed dogs, such as Pomeranians, Chihuahuas, Shih Tzus, etc., but large breed dogs can also experience this problem. To ensure everyone can find the right treatment and prevention, let's learn about patellar luxation in dogs.
“Patella” or “Kneecap” (patellar) The patella is a flat, oval-shaped bone located in the knee area. Normally, the patella rests in a groove in the middle of the knee. There is a tendon of a group of muscles that attach to the muscles to the pelvis that runs through it, keeping the patella in the groove. When the dog stretches or contracts its leg, the patella moves up and down in the groove.
Patella luxation In dogs Patellar luxation is an abnormal position of the patella in a dog's position whether it is still or moving. The abnormal patella can slip to either the outside or inside of the knee joint. Normally, the patella is a small piece of cartilage that sits in a groove between the kneecap bones on both sides and is held in place by a group of tendons that run across it. When the body moves so that the hind leg follows suit, the hind leg muscles will stretch and contract, pulling on the tendons. And the patella, which is held in place by the tendons, will move up and down with it. Therefore, it can be seen that leg movement requires many factors. But if there is an abnormality in any part, it will cause the dog's walking or various postures to appear abnormal. The important characteristic is that the patella, which is normally in the groove in the knee, moves incorrectly and slips out of the groove. In some cases, it slips inward.In the knee, some cases come out to the side of the knee, where 80 – 90% tends to come out more inward.
Causes of patellar luxation in dogs
Patellar luxation is most commonly caused by genetic abnormalities in the kneecap structure, and most dogs are born with the condition. Additionally, trauma, car accidents, or even beatings can disrupt the growth spurts in a dog's leg, causing the leg to bend and twist, which can also lead to the patellar luxation.
Severity grade of patellar luxation in dogs
Grade 1 The dog is not showing any symptoms. The patella is still in the groove. When pushing with the hand, it can slide out. When released, it will bounce back into the original groove.
Grade 2 Dogs begin to show symptoms of leg pain and abnormal gait due to the patella dislocating more frequently. When dislocated, it becomes lodged outside the groove. Cartilage in the joint surface may be destroyed, leading to osteoarthritis.
Grade 3 The dog is in pain and unable to straighten its leg, so it often raises its leg or bends its knee joint, refusing to bear weight because the patella is constantly dislocated. Torsion of the leg bone may also occur.
Grade 4 The dog is unable to straighten its knee and walks with a dragging leg. Permanent dislocation of the patella occurs and cannot be pushed back. Twisting and abnormal growth of the leg bone are often found.
If your dog is in the early stages of patellar luxation, you may not notice any symptoms yet as your dog is still walking normally. However, if your dog is walking with a raised leg, twisting the leg, crying out in pain, or unable to straighten the knee joint, you should see a veterinarian as there is a possibility that your dog has advanced patellar luxation.
How to treat patellar luxation in dogs
Treatment depends on the severity of the disease. If symptoms are not severe, medication will be used, along with physical therapy and weight control. However, if symptoms are grade 2 or higher, surgery is necessary. There are several surgical methods, each with the goal of realigning the patella into the groove of the posterior thighbone.
The veterinarian must determine if the ligaments within the knee joint or meniscus are torn and the depth of the knee joint. If it is very shallow, surgery will be required to deepen the groove, which can be done using a number of techniques. Once the patella has been successfully moved back into the knee joint, the alignment of the leg bones must be considered. If the leg remains bent, it could pull the patella out of the knee joint in the future.
Post-operative physical therapy
Physical therapy is often performed on dogs that are still unable to stand or bear weight after surgery, as these dogs have chronic patellar dislocation before surgery. However, dogs that have had surgery have a good outcome and are able to move independently. Dr. Buraphong Suthirat (Dr. Tang), a veterinarian in the Orthopedic and Joint Department at Taling Chan Animal Hospital, has given the following advice:
"For surgery at Taling Chan Animal Hospital, we don't recommend physical therapy. Most dogs will do well on their own anyway. Owners don't need to spend money, as they're already walking well and well. Therefore, after surgery, dogs should be allowed to use their legs immediately. Allow them to walk and use their legs as much as possible."
Guidelines for the prevention of patellar dislocation in dogs
1. Avoid playing activities that may affect the knee joints.
2. Control your weight so you don't become too fat.
3. Exercise your dog regularly.
4. Dogs aged 6 months and over can be brought to see a veterinarian for examination.
Patellar luxation is a disease that all dog owners should not overlook, as it directly impacts the lives of our beloved dogs, especially small breeds. If you find that your dog is at risk of patellar luxation, you should immediately take him to see a veterinarian so that the initial symptoms can be identified and treated promptly. Or, you can bring him in for a checkup from a young age.
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References
Dr. Buraphong Suthirat (Dr. Tang), veterinarian, Orthopedic and Joint Department, Taling Chan Animal Hospital
Pet MD. (2016). Patellar Luxation in Dogs Medical Diagram. Retrieved July 1, 2021, from Pet MD: https://www.petmd.com/dog/infographic/patellar-luxation-dogs-medical-diagram