Canine Luxating Patella: Surgical Repair Options for Patellar Luxation in Dogs

Luxating patella is the dislocation of the kneecap–the small bone in front of the knee joint.

Your veterinarian might recommend surgical intervention for patellar luxation grade II or higher.

Canine Luxating Patella: Surgical Repair Options for Patellar Luxation in Dogs

Kneecap anatomy

At the top, the kneecap attaches to the quadriceps tendon and at the bottom to the patellar ligament. The kneecap not only protects the front of the knee. It also assists with the joint movement–straightening of the knee.

In a normal knee, the femoral groove constrains the kneecap movement. The groove allows the patella to slide up and down but not to the side. When the kneecap luxates–slips out from the groove–it impairs the function of the joint.

Canine Luxating Patella: Surgical Repair Options for Patellar Luxation in Dogs
Patella/kneecap. Image The Code Company

Kneecap dislocation grades

Luxating patella grading is based on whether the kneecap

  • pops back into proper position on its own
  • can be pushed back into the groove
  • or stays dislocated, and how often this happens
Grade Ithe patella can be manipulated out of groove but returns into position on its own
Grade IIkneecap occasionally rides out but can be manipulated back into position
Grade IIIkneecap frequently dislocates but can be placed back
Grade IVdislocated kneecap remains dislocated

The grade determines treatment options.

If the kneecap dislocates frequently, or cannot be pushed back into place, veterinarians recommend surgery.

A genetic predisposition is the main predictor of patellar luxation. Trauma is rarely the cause.

The problem behind patellar luxation goes beyond a shallow groove–its a result of faulty biomechanics and conformation.

The rather complex issue might involve :

  • an abnormal hip joint
  • abnormalities in the conformation of the thigh and shin bones
  • a patellar ligament that is too long
  • muscle issues

The surgical repair might involve a combination of deepening of the groove and/or realignment of other parts.

Tibial Tuberosity Transposition

This surgery realigns the pull on the kneecap. It does involve cutting the bone to which the patellar tendon attaches and securing it into a position where it better aligns with the groove. The reasoning behind this method is that bone heals better than a tendon would.

Tibial Tuberosity Transposition. Image North Downs Specialist Referrals

Recession sulcoplasty/Trochleoplasty

This is the most obvious repair-deepening of the groove if it is very shallow.

Ridge Stop

This procedure involves placing an implant which increases the height of the affected ridge. Most commonly, the patella dislocates medially, toward the inside of the leg.

Medial muscle release

With a prolonged dislocation, the muscles opposite of the position of the kneecap stretch and the ones on the same side shorten. Once things are in their proper position, the surgeon will tighten the loose muscles and free up the tight ones.

Femoral osteotomy

This is a procedure to straighten the thigh bone in dogs who have a severe bow.

The surgeon removes a wedge of the thigh bone and secures it with a plate and screws to become more straight.

A potentially much more complicated fix than you’d think, isn’t it?

Fortunately, unless your dog has other issues, such as hip dysplasia, the outcome of surgical repair is quite positive. In such cases, the chances that lameness returns are low.

Related articles:
Primer on Patellar Luxation in Dogs
Juno’s Luxating Patella

Further reading:
Patellar Luxations

Categories: ConditionsJoint issuesKnee issuesLuxating patella

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Jana Rade edited by Dr. Joanna Paul BSc BVSc

I am a graphic designer, dog health advocate, writer, and author. Jasmine, the Rottweiler of my life, was the largest female from her litter. We thought we were getting a healthy dog. Getting a puppy from a backyard breeder was our first mistake. Countless veterinary visits without a diagnosis or useful treatment later, I realized that I had to take Jasmine's health care in my own hands. I learned the hard way that merely seeing a vet is not always enough. There is more to finding a good vet than finding the closest clinic down the street. And, sadly, there is more to advocating for your dog's health than visiting a veterinarian. It should be enough, but it often is not. With Jasmine, it took five years to get a diagnosis. Unfortunately, other problems had snowballed for that in the meantime. Jasmine's health challenges became a crash course in understanding dog health issues and how to go about getting a proper diagnosis and treatment. I had to learn, and I had to learn fast. Helping others through my challenges and experience has become my mission and Jasmine's legacy. I now try to help people how to recognize and understand signs of illness in their dogs, how to work with their veterinarian, and when to seek a second opinion. My goal is to save others the steep curve of having to learn things the hard way as I did. That is the mission behind my blog and behind my writing. That is why I wrote Symptoms to Watch for in Your Dog, which has turned out being an award-winning guide to dog owners. What I'm trying to share encompasses 20 years of experience. Dr. Joanna Paul BSc BVSc is our wonderful sponsor and has been kind to edit and fact-check my important articles.

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