Luxating Patella in Dogs 

Luxating Patella in Dogs 

Luxating patella in dogs, or patellar luxation, is a common orthopedic condition where the kneecap (patella) slips out of its normal groove within the femur. This can lead to discomfort, pain, and difficulty walking or moving the affected leg. 

The severity of the condition can vary, with some dogs experiencing occasional, mild luxation, while others may suffer from chronic or severe dislocations. Luxating patella can be caused by  trauma, or an abnormal bone structure, and is often seen in smaller dog breeds. Treatment options range from conservative management with anti-inflammatory medications and physical therapy to surgical intervention, depending on the severity and specific circumstances of each case. 

What Causes Luxating Patella? 

Luxating patella, a common orthopedic condition in dogs, can be attributed to various factors that contribute to the dislocation of the kneecap. The three main causes of the luxating patella in dogs are genetic factors, trauma, and abnormal bone structure, which together can help us better understand this condition and determine appropriate prevention and treatment strategies. 

Genetic Factors: In many cases, a luxating patella is a hereditary condition that is passed down through generations, especially in smaller dog breeds such as Pomeranians, Yorkshire Terriers, and Miniature Poodles. Responsible breeding practices can help reduce the prevalence of this condition in susceptible breeds. 

Trauma: An injury to the knee joint, such as a direct blow or an awkward landing from a jump, can cause the patella to luxate. Immediate veterinary care is essential to assess the damage and determine the most appropriate treatment to restore the kneecap to its proper position. 

Abnormal Bone Structure: Dogs with congenital or developmental abnormalities in their knee joint or leg bones may be more prone to experiencing luxating patella. In these cases, surgical intervention may be required to correct the underlying structural issue and prevent the patella from dislocating repeatedly. 

How Is A Luxating Patella Diagnosed and Graded? 

A luxating patella, also known as a “floating” or “dislocating” kneecap, is a common orthopedic condition in dogs, particularly in small and toy breeds. It occurs when the kneecap moves out of its normal position in the groove of the femur, causing discomfort and potential mobility issues. To diagnose and grade a luxating patella, veterinarians typically follow these steps: 

Luxating Patella Diagnoses 

• Physical examination: The first step in diagnosing a luxating patella is a thorough physical examination. The veterinarian will manipulate the affected leg, checking for signs of pain, discomfort, or instability. They will feel for the kneecap’s location and its ease of movement in and out of its normal position. 
• Palpation: The veterinarian will apply pressure to the kneecap, attempting to manually move it out of the groove in the femur. If the patella can be easily moved, this is an indication of a luxating patella. 
• Gait analysis: The veterinarian may observe the dog’s gait to identify any abnormalities, such as limping, skipping, or hopping, which could be indicative of a luxating patella. 
• Radiographs (X-rays): In some cases, the veterinarian may recommend radiographs to assess the severity of the condition and rule out other potential causes of the dog’s symptoms. X-rays can reveal the position of the patella, the depth of the femoral groove, and any associated bone or joint abnormalities. 

Grading Scale of Luxating Patella in Dogs 

Diagnosing a luxating patella, or dislocated kneecap, in dogs involves a physical examination, palpation, and gait analysis to assess pain, instability, and irregular movement. In some cases, radiographs (X-rays) may be needed for further evaluation. Once diagnosed, the veterinarian grades the severity of luxating patella from Grade 1 (mild) to Grade 4 (severe) to determine the appropriate treatment. 

• Grade I Patellar luxation: In this mild form, the patella can be manually luxated (moved out of its normal position), but it spontaneously returns to its normal position when released. The dog may not show any signs of pain or discomfort, and the condition may not require surgical intervention. 
• Grade II Patellar luxation: At this stage, the patella can be manually luxated or may spontaneously luxate on its own, and it does not always return to its normal position without manual manipulation. Dogs with Grade 2 luxating patella may exhibit intermittent lameness or discomfort. Conservative management, such as weight control and joint supplements, may be recommended, but in some cases, surgical intervention may be necessary. 
• Grade III Patellar luxation: In Grade 3, the patella is frequently luxated and remains out of position most of the time. Manual manipulation may be needed to return it to its normal position. Dogs with this grade may have persistent lameness and discomfort, and surgical intervention is usually necessary to prevent further joint damage and alleviate pain. 

• Grade IV Patellar luxation: This is the most severe form of luxating patella, where the patella is permanently luxated and cannot be manually returned to its normal position. Dogs with Grade 4 luxating patella often exhibit significant lameness, discomfort, and joint deformities. Surgical intervention is required to correct the problem and improve the dog’s quality of life. 

Luxating Patella Variations 

Luxating patella variations in dogs refer to the different ways the kneecap can dislocate and the range of severity it may present. The patella can either have a medial or a lateral luxation based on the underlying cause.  

Medial Patella Luxation 

Medial luxation is a type of patellar luxation where the kneecap (patella) dislocates towards the inner side of the dog’s leg. It is the most common form of patellar luxation, particularly in small and toy dog breeds. This condition occurs when the patella slips out of its normal position in the trochlear groove of the femur, causing discomfort, pain, and potential mobility issues. 

Medial patellar luxation can be a condition that a dog is born with (congenital or hereditary), or acquired due to trauma or injury. 

Lateral Patellar Luxation 

Lateral luxation is a type of patellar luxation where the kneecap (patella) dislocates towards the outer side of the dog’s leg.  

Lateral luxation is less common than medial luxation and is more frequently observed in larger dog breeds. Like medial luxation, lateral luxation can be congenital, hereditary, or acquired due to trauma or injury. 

Luxation From Trauma 

Luxation from trauma refers to the dislocation of a joint or the displacement of a bone, such as a patella (kneecap), due to an external force or injury. In the case of patellar luxation, trauma-induced luxation can occur in any dog breed, regardless of size or predisposition to the condition. 

Traumatic luxation can result from various incidents, such as falls, collisions, or accidents, where the impact on the joint or bone is significant enough to cause dislocation. Unlike congenital luxation, which is a result of genetic predisposition and developmental abnormalities, luxation from trauma is not hereditary and typically occurs as an isolated incident. 

Signs of Luxating Patella 

A luxating patella can manifest in various ways, depending on the severity of the condition. Here are three common signs that may indicate a dog is experiencing a luxating patella: 

Intermittent lameness or limping 

A dog with a luxating patella may exhibit sudden lameness or limping in the affected leg. They may hold the leg up for a few steps, then resume walking normally, as the patella pops back into its normal position. 

Skipping or hopping 

Dogs with a luxating patella may display an unusual gait, which can include skipping or hopping on one or both hind legs. This behavior can occur when the patella dislocates and then relocates, causing the dog to momentarily lift the affected leg off the ground. 

Consistent lameness or limping 

In the higher stages of patellar luxation, a dog may have a consistent limp that does not seem to improve with rest or pain medication.  

Pain or discomfort 

A dog with a luxating patella may show signs of pain or discomfort, particularly when the patella dislocates. They might cry out, avoid putting weight on the affected leg, or lick or chew at the area around the knee. 

What Type of Surgery for Luxating Patella? 

There are several surgical techniques to correct a luxating patella, depending on the severity of the condition and any associated abnormalities. The choice of surgery is typically based on the individual needs of the dog and the surgeon’s expertise. Some common surgical techniques for treating a luxating patella include: 

1.  Trochleoplasty: This procedure involves deepening the groove (trochlear groove) in the femur where the patella normally sits. A deeper groove helps keep the patella in place and reduces the risk of luxation. 

2. Tibial tuberosity transposition: In this procedure, the surgeon repositions the tibial tuberosity, which is the bony attachment point for the patellar ligament on the tibia. This is achieved by making a cut vertically through this bony protuberance, correcting the alignment of the patellar tendon, and then using orthopedic pins to hold the tibial tuberosity in its new position until the bone heals over the next 6-8 weeks. By adjusting the position of the tibial tuberosity, the surgeon realigns the forces acting on the patella and stabilizes it within the trochlear groove. 

3. Medial or lateral imbrication (capsular tightening): This technique involves tightening the joint capsule and soft tissues on the side of the luxation (medial or lateral) to provide better support and prevent the patella from dislocating. 

4. Joint ligament reconstruction: In some cases, the surgeon may need to reconstruct or repair damaged ligaments to provide better stability to the joint. 

The chosen surgical technique or combination of techniques will depend on the specifics of each case, including the grade of luxation, the presence of any underlying abnormalities, and the overall health of the dog. A veterinarian or an orthopedic specialist will carefully assess the dog’s condition and recommend the most appropriate surgical approach. The ultimate goal of surgery is to improve joint stability, reduce pain and discomfort, and enhance the dog’s overall quality of life. 

Recovery From Luxating Patella Surgery 

The average recovery time for a dog after luxating patella surgery can vary depending on factors such as the severity of the condition, the type of surgery performed, and the dog’s individual healing process. Generally, most dogs require around 6 to 8 weeks for a complete recovery. However, it’s important to follow the veterinarian’s specific recommendations and closely monitor the dog’s progress throughout the recovery period to ensure a successful outcome. 

The list below outlines the typical recovery timeline and recommended activities during each phase for a dog recovering from luxating patella surgery. It provides guidance on pain management, wound care, activity levels, and follow-up appointments with the veterinarian over the course of a 6-8 week period, ensuring proper healing and a gradual return to normal activity levels for the dog. 

Weeks 1-2 

• Pain management with prescribed medications 
• Wound care and monitoring for signs of infection 

• Strictly limited activity (crate rest or confinement to a small area) 
• Use of an Elizabethan collar to prevent licking or chewing at the surgical site 

Weeks 3-6 

• Gradual increase in activity, as advised by the veterinarian 
• Short, controlled walks on a leash (5-10 minutes, 2-3 times per day) 

• Continued monitoring of the surgical site for proper healing 

Weeks 6-8 

• Further increase in activity levels, as advised by the veterinarian 
• Gradually lengthening walks on a leash 
• A follow-up appointment with the veterinarian for reevaluation and assessment of healing progress 

Weeks 7-12 

• Continued gradual increase in activity, aiming for a return to normal activity levels 
• Monitoring for any signs of discomfort, pain, or limping during activity 
• A final follow-up appointment with the veterinarian to confirm successful recovery and clearance for full activity 

Physical Rehabilitation for Optimal Recovery 

Physical rehabilitation is vital in optimizing your dog’s recovery following ELSS surgery. A customized therapy plan, often designed with a certified companion animal rehabilitation therapist, can help improve your dog’s range of motion, muscle strength, and overall mobility. Techniques such as passive range of motion exercises, controlled walking, and weight-shifting exercises can be incorporated into your dog’s rehabilitation plan. 

Additional modalities like hydrotherapy, massage, and therapeutic laser treatment may also be beneficial in promoting healing and reducing inflammation. A well-designed rehabilitation program can not only speed up your dog’s recovery process but also improve its long-term joint health and functionality.