Canine patellar luxation is a common orthopedic condition where the kneecap (patella) slides out of its normal location in the groove at the end of the thigh bone (femur). In most cases, this condition affects both hind legs, but it can occur in only one leg. Patellar luxation can range from mild to severe and can cause pain, lameness and decreased range of motion in the affected joints.
The exact cause of patellar luxation isn’t unknown, but there are several factors that can contribute to the development of this condition. Congenital deformities, such as hip dysplasia, a shallow femoral groove or an abnormal patella shape, can predispose a dog to developing patellar luxation. Traumatic injuries, such as a fractured femur or tibia, can also lead to patellar luxation.
Symptoms of Canine Patellar Luxation
The most common symptoms of patellar luxation include:
- Pain
- Lameness
- Decreased range of motion in the affected joints
These symptoms can range from mild to severe depending on the severity of their luxation. Other signs can include:
- Swelling
- Muscular atrophy (decrease in muscle mass)
- Difficulty getting up from a lying position
In some cases, dogs can have a “bouncing” gait when walking.
Diagnosing Canine Patellar Luxation
Patellar luxation is usually diagnosed by a physical exam performed by a veterinarian. During the exam, the vet will feel for looseness in their knee joint and can attempt to manually relocate their kneecap back into place. X-rays could also be taken of the affected joints to assess the degree of luxation and to check for signs of joint degeneration or other abnormalities.
Stages of Canine Patellar Luxation
Canine patellar luxation is typically split into four stages, ranging from mild to severe. The stages are based on the degree of displacement and instability of their kneecap and range from Grade I (mild) to Grade IV (severe).
Stage 1
In stage 1 the patella is slightly displaced out of the femoral groove and can be easily relocated by manipulation.
Stage 2
In stage 2 the patella is partially out of the groove and could need slight manual manipulation to relocate it.
Stage 3
In stage 3 the kneecap is completely out of its normal position and can’t be relocated manually.
Stage 4
This is a severe form of luxation associated with a complete dislocation of the patella and permanent joint deformity.
Treating Canine Patellar Luxation
Treating patellar luxation will depend on the severity of their condition. For mild cases, the vet could recommend weight management and exercise to help strengthen their affected joints. Anti-inflammatory medications can also be prescribed to reduce pain and swelling. In more severe cases, surgery will usually be necessary to correct the problem. The type of surgery performed will depend on the degree of instability in the joint, and could involve realigning the femur and tibia or removing part of the patella. After surgery, physical therapy will be recommended to help strengthen their joints and restore their range of motion.
Preventing Canine Patellar Luxation
Patellar luxation can be prevented by making sure your pet maintains a healthy weight and gets plenty of exercise. Regular check-ups with your vet are also important to ensure that any underlying conditions, such as hip dysplasia, are detected and addressed before they can contribute to this condition.
Regular physical activity is important to ensure that their joints remain strong and flexible, reducing the risk of developing luxation. If your pet has been diagnosed with hip dysplasia or another condition that increases the risk of luxation, your vet will likely recommend supplements or other treatments to help reduce the likelihood of developing this condition.