What is Patellar Luxation?
The patella, or kneecap, is part of the stifle joint (knee). In patellar luxation, the kneecap luxates, or pops out of place, either in a medial (toward the inside) or lateral (toward the outside) position.
Bilateral (both knees) involvement is most common, but unilateral (one knee) is not uncommon. Cavaliers can be affected at a very young age as well as later in life, but typically it occurs in Cavaliers within the first year to eighteen months.
Although the luxation may not be present at birth, the anatomical deformities that cause these luxations are present at that time and are responsible for subsequent recurrent patellar luxation. Patellar luxation should be considered an inherited disease.
Signs vary dramatically with the degree of luxation. In Grade 1 there may be no indication initially and diagnosis can only be made by palpation. Over time, with further breakdown of soft tissues, the dog may become lame. In Grades 2-3 lameness may only be evident when the patella is in the luxated position. In Grades 3-4 dogs may exhibit a crouching, bowlegged stance with the feet turned inward and with most of the weight transferred to the front legs. Pain can be present in some cases however most animals seem to show little irritation for Grades 1-2.
Sudden bilateral luxation may render an older Cavalier unable to stand and so simulate neurological disease. Care must be taken not to misdiagnose patellar luxation for some form of neurological problem.
Most Cavaliers can lead a normal, pain free life with Grade 1 patellar luxation; however surgery is highly successful for the more severe forms of this disease. There seems to be a vast difference in charges for this surgery and owners are encouraged to obtain estimates from a variety of different veterinarians and orthopedic specialists.
Thank you so much, CKCSC-USA, for this helpful information!