Is your pet experiencing discomfort or limping as a result of patella luxation or has your vet advised you that patella luxation is a problem for your pet? The aim of this page is to provide knowledge on patella luxation, a common orthopedic condition affecting dog’s kneecaps. We’re here to guide you through understanding, managing, and improving your companion’s quality of life.
Normal Patella Anatomy
The patella is synonymous with the kneecap, a small bone located in the front of the knee joint. The patella is a sesamoid bone, meaning it develops within a tendon to help tissue glide over a joint. The patella helps the quadriceps tendon glide over the joint. Proper gliding improves mechanical efficiency of the quadriceps muscle group, which is responsible for extending the leg at the knee joint.
About Patella Luxation
Canine patella luxation, also known as a floating kneecap, is described as having the patella pop out of its normal position. Patella luxation occurs when a variety of factors contribute to pulling the kneecap out of its normal position within the groove of the femur. This results in pain and instability in the knee joint. The patella may luxate, or dislocate, either toward the inside (medial) or the outside (lateral) of the knee joint.
Signs of Patella Luxation
Common signs of patella luxation include intermittent limping, skipping or hopping on one or both hind limbs. Sometimes a patient simply has difficulty bearing weight on the affected leg. In more severe cases, a patient may be completely non-weight bearing. If you see any of these problems in your companion, it warrants an evaluation to ensure a prompt and accurate assessment of your pet’s condition.
Severity of Patella Luxation
Patella luxation is graded on a scale from I to IV, with Grade I being mild and Grade IV being the most severe. In Grade I, the patella can be manually manipulated out of place but returns to its normal position spontaneously. Grade I patella luxation may not require any treatment other than weight management. In more severe cases (Grades II to IV), the patella may dislocate more frequently and may not easily return to its normal position resulting in pain and lameness.
Etiology – Causes of Patella Luxation
Patellar luxation can be classified as congenital (present at birth), developmental (develops during puppyhood) or traumatic (injury). The vast majority of the cases are developmental and the contributions are multifactorial. Genetic predispositions can contribute to patella luxation. Small and toy breeds, such as Chihuahuas, Pomeranians, Yorkshire Terriers, and Miniature Poodles, are commonly affected. Anatomical abnormalities also contribute to the problem. Normally, the patella glides within a groove located on the femur. If this groove does not develop correctly or is more shallow than a normal dog, the patella can more easily pop out. Abnormal limb alignment can cause deviations of the bones of the hind limbs, such as bowing or twisting. These deformities can increase the risk of patella luxation. Muscle imbalances, including weak or unbalanced quadriceps muscles also contribute to the problem. Certain muscles that are overly tight or contracted can influence the positioning of the patella.
Diagnosis
Diagnosis of patella luxation is not simply verifying that a patient does or does not have patella luxation. The surgeons and Spry Companions are skilled at identifying the underlying causes of the problem. Depending on what is appreciated in the patient and on radiographs (x-rays), a CT scan may be warranted to fully understand the relative contribution of bony deformities to the overall patella luxation.
Managing Patella Luxation – Comprehensive Solutions at Spry Companions:
The surgeons at Spry Companions will help you determine if surgery is indicated. If surgery is recommended, it could range from simple basic procedures to more complicated deformity correction. Basic procedures may involve deepening of the groove, realignment of the tibial tuberosity, tightening of loose tissue and releasing contracted tissues. In deformity cases, we will utilize 3D printing and custom jig development to aid in surgical planning. In other cases, we may recommend patellar groove replacement. We are also proponents of physical therapy and pain management. We provide insights into the factors influencing treatment decisions and help you find the best approach for your companion.
Click here to learn more about deformity corrections.