LUXATING PATELLA

Introduction
* The patella (commonly known as the kneecap) normally rides in a groove at the bottom of the femur at the level of the knee joint in a groove called the trochlear groove; Fig 1 and 2 show a front view of the knee joint; Fig 1 demonstrates the patella in the groove, where as Fig 2 demonstrates the knee cap dislocated out out of the groove (P=patella; F=femoropatellar ligaments which hold the patella in the groove; PL=patellar ligament; G=trochlear groove that the patella rides in). Fig 3 demonstrates a skyline view of the trochlear groove and the patella - you are looking down the thigh or femur bone toward the knee joint; take note of the deep groove that is found in a normal animal.

* Patellar luxation is caused by congenital abnormality usually at the level of the hip joint and results in abnormal forces on the kneecap, which cause it to eventually ride outside of the groove. The groove becomes very shallow and the attachment of the ligament of the patella may be malpositioned on the tibia bone. If the patellar luxation occurs in immature animals, the tibia and femur bones become twisted.



Clinical signs
* Lameness
* Intermittent skipping gait
* Pain
* Stiffness of the hind limb
* Some pets show only a single sign, whereas others show many signs of the condition
* Failure to treat the condition could lead progressive debilitating arthritis of the joint

Surgery
*If the groove that the patella rides in is shallow or misshapen, it is surgically deepened; we usually use an advanced technique to perform this called the block osteotomy. The illustration right demonstrates elevation of the cartilage/bone plate. I now use a modified procedure in which the cartilage/bone plate is left attached to the soft tissues (periosteum) at the top of the groove, thus minimizing the risk that the cartilage/bone plate will become displaced in the joint.

*Additional bone is removed from the raw bone bed and the cartilage/bone plate is replaced creating a deep groove for the patella to ride in. The benefit of the block osteotomy is that it uniformly deepens the groove from top to bottom and preserves the cartilage that the patella rides on.

*If the attachment of the patellar ligament to the tibia, called the tibial crest, is in the wrong position, it is repositioned. This is done by creating a cut in the tibial crest (see illustrations below) and reattaching the bone in a position so that the patella is realigned within the trochlear groove. Pins are used to fasten the bone in place; the pins usually do not need to be removed unless they migrate out of position or a bubble of fluid (seroma) develops over the end of the pin.

* The soft tissues along the side of the patella usually are stretched and are tightened to provide additional support to keep the patella in the trochlear groove.

*The femur bone may be twisted in some dogs which worsens the condition of the luxating patella. I find that dogs that have a greater than 14 degree bowing (varus) of the thigh bone should have this surgically corrected. Special alignment x-rays are usually taken in large breed dogs to check for this problem.

*A support bandage is usually not used after surgery so that rehabilitation therapy can be started soon after surgery

Convalescence
* By 10 to 14 days after the surgery your pet should be touching the toes to the ground at a walk
* By 2 to 3 months after surgery your pet should be using the limb well
* If your pet does not follow a normal progression of recovery, the surgeon should be notified

Prognosis
* Surgery has approximately a 90% success rate. Success is defined as the return of good function of the limb
* Unfortunately surgery will not remove the arthritis that may already be present in the knee. As a result, your pet may have some stiffness of the limb in the mornings or after laying down for a nap. In addition, your pet may have some lameness after heavy exercise
* By having the surgery done earlier, the chance of developing significant arthritis is decreased
* Dogs that have a higher grade of patellar luxation may have increased risk for reluxation of the patella
* Large breed dogs that have patellar luxation may have increased risk for reluxation of the patella if a corrective femoral osteotomy is not performed

Potential complications
* There is an inherent risk of anesthetic death with any procedure requiring anesthesia, however, this is very small
* Infection of the surgical site, although not common, can occur
* Pin migration
* Seroma formation over the pins
* If exercise is not minimized for 8 weeks after the surgery, breakdown of the repair may occur, thus requiring a second surgery

Natural ways to treat Luxating Patellas:

Keep your dog lean. (Fat dogs have to carry more weight on their weak leg joint).

Moderate exercise, walking up slight inclines (gentle hills), will strengthen the muscle groups around the patella.

Vitamin C is one of the building blocks of strong ligaments and connective tissue.

Glucosamine supplements or Glyco-Flex are nutritional products packed with minerals, amino acids, enzymes, and lubricating agents. They build cartilage and cushioning fluid in injured joints, and help heal damaged connective tissue.

Acupuncture, Homeopathy and even the application of therapeutic grade essential oils have also been very effective in correcting luxating patellas and strengthening the joints and tendons while easing the pain.

There are four degrees (grades) of luxation:

Grade I. The knee only slips out when the vet manipulates it.

Grade II. The knee luxates occasionally when the dog is walking or running. He/she may not seem to mind much, or they may shriek, but it usually slides back by itself as they continues moving. Or you can slip it back manually (ask the vet to show you how).

Grade III. The knee luxates frequently and causes chronic lameness. Even when you put it back manually, it doesn't seem to last long.

Grade IV. The knee luxates, stays that way, and you can't put it back into its socket. This grade is very rare but happens.

How appropriate to see this-we just got back from the vet and Sophie has LP (is there anything that girl DOESN'T have? sheesh!). Luckily it's mild, and she's not overweight so hopefully we can just watch it.

Saira wrote:How appropriate to see this-we just got back from the vet and Sophie has LP (is there anything that girl DOESN'T have? sheesh!). Luckily it's mild, and she's not overweight so hopefully we can just watch it.

We recently found out that Nell does too. It's not mild but so far she doesn't seem bothered by it.

I think we need a poll here to see how many of us have been through at least one pug with LP!!

Ichiro had grade III, and had surgery when he was just 11 months old. But, the surgery was a huge success and I am so grateful we were able for afford it for him!

Thurston had LP surgery at 1 1/2 years old and Kimchi had LP surgery 3 weeks before i got her in S. Korea. That still leaves 2 more legs that can go! (I HOPE not!)

I had a foster puppy that was grade III at only 6-7 months old who had the surgery and he's doing great now. Buster was diagnosed several years ago as a grade I or II (we've just kept him on a glucosamine/chondroitin supplement) but he has been favoring his left rear leg pretty badly for the last 24 hours. This isn't the first time that it's happened but it usually clears up by the time that I can get him into the vet. Luckily, he was already scheduled to see the vet today for shots.

Brenda, how did Buster's vet appointment go today?

Grace had LP surgery on her left knee 2 years ago and made a full recovery. She does have LP in her right knee - Grade 2 I believe, but so far it's been ok (knock on wood). Kayla also has LP in both knees, but honestly, with all her other back end problems, she'll never have surgery for LP.

When Ruby was 1 year old to 3 years old she had LP on both knees, the vet at that time said it was in between Grade II and Grade III though if i
recall...

She was also close to 30lbs though.

Luckily it was fixed completely by her dropping to 15-17lbs.

Peanut is the only one of my herd of 9, that has lux pat. I would say she is between 3 and 4 on both legs. After we had resolved most of her spinal injuries, we had surgery on one knee, and she did well for a few wks. That was it! Because spinal dogs flip their legs backwards all the time, she completely destroyed the surgery and is now back to her cart. The good news is that she does not have pain at all, and she loves her cart. she is the fastest in her cart of all my guys, too bad there are not races! It is shame, as she is so active, and we think she is relatively young. But she is happy for sure!!

dieselsmom wrote:Brenda, how did Buster's vet appointment go today?

The vet thinks that he is favoring the leg due to his low grade LP and arthritis. We're supposed to give him 1/2 of a Tramadol for pain whenever he's experiencing symptoms. They don't think it's severe enough to require surgery.

Thank you for this information.

This happened to a pug in our meet-up group. The owner said, the pug jumped out of the car and landed wrong, causing the patella to move.

Zoe had the surgery at 7 mos. She's now 5 1/2 and doing very well, though still severly bow legged. I know it's a sign of really poor breeding, but I find it endearing.

My little Justice is only 16 weeks old, but at 8 weeks was diagnosed with this. So far, he hasn't shown any symptoms at all. If the vets (mine and the breeders') had not found it, we wouldn't know he had it. I know that can change though. The weird thing was, he was at the vet and they found it while we were on our very long trip to pick him up! We decided to take him anyway, and he and his "sister" Liberty are doing great!
Here he is: (I hope it's O.K. to post a picture)

My Morgan was only 2 when we first had to deal with it...she was stage 2 but we got her to loose some weight, and we got her on some hip and joint treats and supplements and we've seen a great improvement - we also try to avoid situations in which she has to walk on rocks or uneven surfaces which is when she would pop her little knee out of place...we also spent the money and invested in sir beds which are said to be better for joints and we have seen improvement but we started all those things at the same time so we aren't sure what worked best but we are happy with the improvements in Morgan!  *D'Arcy seems to be comfortable and pleased too*

Denika wrote:My little Justice is only 16 weeks old, but at 8 weeks was diagnosed with this. So far, he hasn't shown any symptoms at all. If the vets (mine and the breeders') had not found it, we wouldn't know he had it. I know that can change though. The weird thing was, he was at the vet and they found it while we were on our very long trip to pick him up! We decided to take him anyway, and he and his "sister" Liberty are doing great!
Here he is: (I hope it's O.K. to post a picture)

Just so you know, puppies CAN have loose knees, but it isn't necessarily a sure sign that they have LP. I don't take an LP diagnosis seriously until the dog is fully grown. I've had several pups in foster care who were diagnosed with LP, but by the time they hit 1- 2 years of age, the LP was no longer evident.

Weight management is CRUCIAL for joint issues.

Wow! That is great news to hear, and makes me feel a little better! Hopefully it won't become a problem, but we are going to be extra careful about his weight!
Thank you!

Denika wrote:Wow! That is great news to hear, and makes me feel a little better! Hopefully it won't become a problem, but we are going to be extra careful about his weight!
Thank you!

Just so you know--this is my own personal bias. I won't do any surgery on nares, LP or ESP when a dog is under the age of 8 or 9 months. I just feel that most of these issues can't be accurately diagnosed in puppies who haven't finished their full growth, bone and muscle development. I can't tell you how many pups have come into rescue with a vet recommendation of nares surgery only to find that by the time they hit a year of age, the nares and/or soft palate were fine.

In rare cases, I've had a dog where the patella clearly was severely out of alignment at a young age, but in my experience, it's rare.

And for what it's worth, LP is an issue with most toy breeds. It's one of the many reasons why breeding for smaller and smaller dogs is such a rotten idea.