Floating Patella
Issue Description
Is a condition in which the patella, or kneecap, dislocates or moves out of its normal location.
Other Names
Luxating Patella, Trick Knee, Subluxation of Patella
Symptoms
Most cases of patellar luxation are medial and this is frequently a congenital problem in toy and miniature breed dogs. Breeds showing a predisposition for medial
patellar luxation include miniature and toy poodles, Yorkshire terriers, Pomeranians, Pekingese, Chihuahuas and Boston Terriers. Large breed dogs are also affected
and the Labrador retriever seems particularly predisposed.Patellar luxation is less common in cats than in dogs. Predisposed breeds include the Devon Rex and the
Abyssinian. Although the specific cause of patellar luxation is unknown in these cases, it is generally agreed that a defect in hind limb conformation is the
underlying cause.
It can be caused by some form of blunt trauma, or may be a congenital defect. In congenital cases, it is usually bilateral.
Diagnosis
Diagnosis is made through palpation of the knee. X-rays are necessary in some cases. The luxating patella often causes no or very slight symptoms. There may be
intermittent limping in the rear leg. Osteoarthritis can develop secondarily.
There are four diagnostic grades of patellar luxation, each more severe than the previous:
Grade I - the patella can be manually luxated but is reduced (returns to the normal position) when released;
Grade II - the patella can be manually luxated or it can spontaneously luxate with flexion of the stifle joint. The patella remains luxated until it is manually
reduced or when the animal extends the joint and derotates the tibia in the opposite direction of luxation;
Grade III - the patella remains luxated most of the time but can be manually reduced with the stifle joint in extension. Flexion and extension of the stifle results
in reluxation of the patella;
Grade IV - the patella is permanently luxated and cannot be manually repositioned. There may be up to 90 percent of rotation of the proximal tibial plateau. The femoral
trochlear groove is shallow or absent, and there is displacement of the quadriceps muscle group in the direction of luxation.
Treatment
Grades III and IV, as well as some grade II cases, require surgery to correct, if the animal has difficulty walking. The surgery involves a sulcoplasty, a deepening
of the trochlear sulcus that the patella sits in.
Additional help can be given with the use of pet ramps, stairs, or steps. These can help the animal
travel from one place to another, especially up and down, without adding any pain or damage to the patella.
The material and information on this website, including any merchandise, information or service provided through this website, is provided "as is"
with all faults and without warranty of any kind from the Furry Critter Network, expressed or implied. In no event shall the Furry Critter Network be
liable for any direct damages, special, incidental or consequential damages, lost profits, or any indirect damages arising from the use or inability
to use this website, even if the Furry Critter Network has been informed of the possibility thereof.