Surgical Stabilization of a Medial Patellar Luxation

Dogs are frequently presented to a veterinarian for intermittent or consistent lameness or reluctance to walk or jump. When a small or miniature breed has this symptom, the patella could be in a luxated position and need to undergo surgery.

Where is the patella located?
The patella or “kneecap” is a small bone that protects the knee joint. It is located at the front of the knee where both femur and tibia join together. During the walk, the patella slides up and down within the groove of the femur.

What is a medial patellar luxation?
It is when the patella moves outside of the femoral groove. The term “medial luxation” refers to the patella moving outside the groove towards the inside (median plane) of the knee. The severity of patellar luxation is defined by four grades: grade I, II, III, and IV; “grade four” being the worst. When the patella is in a luxated position (outside the groove) it affects the normal biomechanics of the knee joint.

Who are the candidates for surgical stabilization of patellar luxation?
Any dog showing a constant or intermittent lameness due to patella luxation of a grade equal or superior to two (II). It mainly affects small breeds, in particular: Pomeranians, Yorkshire terriers, chihuahuas, French bulldog, Cavalier King Charles, Pugs, Jack Russel, miniature Poodles, Maltese… not forgetting cats.

Why are small breeds most affected?
Causes for patellar luxation are genetic and include:

What are the main objectives of the surgery?

    1. Restoring normal biomechanics of the knee joint
    2. Preventing developments of significant arthritis (largely detrimental to the knee).
    3. Reducing worsening of limb deformity
    4. Reducing risk for the development of cranial cruciate injury

What are the surgical steps of patellar luxation surgery?

abvc xray of knees

Figure 1: X-ray showing the “bow-legged syndrome” on a 3-year-old Pomeranian with both patella in luxated position and tibial crests rotated internally.
Figure 2: X-ray of a normal knee showing the patella within the groove and the tibial well aligned with the femur
Figure 3: Post-operative views of a patella re-positioned within the groove (right view) and tibial crest realigned and fixed with two small pins

Prognosis and aftercare
In our experience at Al Barsha Veterinary Clinic, more than 90% of owners are satisfied with the outcome of the surgery with a normal return in function on the operated knee. Post-operative relapses exist but their incidence is low with 10% or less of the operated dogs. Post-operative infection is a rare complication. The outcome on arthritis development is good but operated dogs might need to remain on anti-arthritic food supplements.
After surgery, the doggy will start using his/her leg within two weeks after surgery. Doggy will have to observe an exercise restriction of 4 to 6 weeks which can be followed by a rehabilitation program, but this is often not necessary since the leg function is always better after surgery than before.

Contact our clinic at 04 340 8601 for consultation or for routine surgeries or advanced surgical treatments for your pet in Dubai.

 

Written by Dr. Mehdi Mzabi, ABVC Partner and Veterinarian

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