Luxating Patella in Dogs


Luxating Patella in Dogs

Luxating patella is a common orthopedic condition that can occur in dogs. In fact, according to the American College of Veterinary Surgeons, (ACVS), the condition occurs in about seven percent of all puppies.

The patella is the kneecap, and if it moves out of its correct alignment, the condition is referred to as luxating patella. Normally, the patella sits in the grove called the tibial crest. This position allows the kneecap to move up and down when the knee is bent. The action of the patella helps guide the movement of the muscles in the lower leg called the quadriceps.

But in some dogs, the patella luxates, which means it moves outside the grove. This dislocation of the patella from its correct position causes the leg to lock up.


Causes of Patellar Luxation

In some instances, luxating patella can develop as the result of an injury, such as trauma to the knee. But in other cases, the cause of the condition is not known. It may occur due to a congenital defect.

Congenital defects, which may contribute to luxating patella are thought to involve skeletal abnormalities, such as a long patella ligament, malformation of the tibia and hip dysplasia.

According to the Colorado State University, luxating patella is more common in smaller breeds under 30 pounds including:


When the condition does occur in larger dogs, it tends to be more common in the following breeds:



Depending on the grade, some dogs may not have any symptoms. When symptoms do occur, they may include limping and lameness, which may come and go.  Lameness refers to a disturbance in gait or stance. Lameness may occur because of pain or abnormal anatomy. Dogs with luxating patella may also skip when they run.

According to the Orthopedic Foundation for Animals, one of the most common symptoms is a knock-knee stance. In some cases, your dog may also yelp in pain, especially when the dislocation initially occurs.

Some dogs may shake or hold up their effected leg to lengthen the quadriceps, which helps the patella return to the correct anatomical position. Usually, the more severe the grade of the disorder, the more likely your dog is to have symptoms. For example, dogs who only have symptoms occasionally, may start to have more frequent and consistent symptoms as the condition progresses.

In more severe cases, complications of luxating patella can develop. The pain can become more severe, which limits activity. The cartilage of the knee can wear away resulting in osteoarthritis. Inflammation can also occur, which may breakdown the ligament.

Another potential complication in severe cases is rupture of the cranial cruciate ligament. The dislocation of the patella can lead to changes in the way the knee moves, which stresses the ligament.



Pictured: Simple diagram of dog patella luxation


Diagnosis sometimes occurs after a routine visit to the vet. During a physical exam, the veterinarian may discover the condition. In other instances, symptoms may be present, which prompt a trip to the vet. The veterinarian will perform an exam and can often diagnose the condition after feeling the unstable kneecap. In some cases, additional tests may be performed pre-operatively if surgery is recommended.

X-rays of the knee and possibly the pelvis to determine the extent of the disease and whether hip dysplasia is present may be done. X-rays are generally quick and are painless for your pup. A CT scan is also sometimes used. A CT can provide three dimensional images of the leg and may be helpful, especially if surgery is performed.

Once a diagnosis is made, the condition is usually classified into one of four grades based on the severity. The grades include the following:

  • Grade 1: The patella may be manually moved out of the grove. But it returns to its normal position without intervention.
  • Grade 2: The patella may spontaneously slip out of the grove occasionally or can be manually luxated, but it can be manipulated back into position.
  • Grade 3: The patella remains out of the grove most of the time, but it can be manipulated back into position.
  • Grade 4: The patella is out of the grove all the time and it cannot be manipulated back into position.


Treatment of Patellar Luxation

Not all dogs will who have luxating patella will require treatment. Dogs who do not have any symptoms may just be monitored. Some dogs, especially small dogs, may live a normal life and function fully without treatment.

In other instances, medical management of luxating patella classified as grade one may be an option for dogs who have symptoms. Medical management involves non-surgical approaches to treating the condition.

Medical management may include non-steroidal medication, which treats inflammation and pain. Keeping your dog at a healthy weight to decrease strain on the knee is also recommended. Physical exercises to strengthen the quadriceps may also be an option.

In dogs who have more advanced disease and are classified as having grade two, three and four luxating patella, surgery may be the best treatment option. There are a few different surgical approaches, which may be used. One procedure is referred to as trochlear modification. The procedure involves creating a deeper groove in the femur to hold the patella in place better.

Another surgical approach involves repositioning the patellar ligament and attaching it to the tibia crest on the opposite of the luxation. Keep in mind, if there is underlying damage to the knee due to arthritis, luxating patella surgery does not reverse arthritic changes.

How well a dog responds to treatment may depend on the severity of the disease and the age at diagnosis. Recovery from surgery may also vary based on the type of procedure. In most cases, a dog will use the affected leg well after about six to eight weeks.

Prognosis for most dogs with luxating patella is good. But there are potential risks to surgery. Although anesthesia is usually safe, there is a possibility of complications from the anesthetic. With most surgeries, there is also a risk of infection. If your dog is too active during the recovery time, it’s also possible the repair can breakdown. Following your vet’s post-operative instructions decreases the chances of complications.


How Much Is Luxating Patella Surgery for Dogs?

The cost of surgery to correct your dog’s luxating patella depends on the severity of the condition, age and size of your dog and where you live. Veterinary surgery costs vary widely depending on the cost of living in your are. With that said here is the average cost for knee surgery for dogs.

Luxating Patella Dog Surgery Cost: $1,500 to $3,000



Incidence by Dog Breed

Each dog breed has unique genetic makeup that causes them to be more or less susceptible to patellar luxation. Here is a list of breeds from the Orthopedic Foundation for Animals. You can also visit the American College of Veterinary Surgeons to learn more about luxating patella dog surgery.

Breed Affected # Evaluations
Pomeranian 37.2% 725
Yorkshire Terrier 24.1% 643
Australian Terrier 18.9% 206
Cocker Spaniel 13.6% 944
Tibetan Spaniel 12.4% 185
English Toy Spaniel 11.5% 131
Mi-Ki 10.8% 222
Boykin Spaniel 10.7% 280
Japanese Chin 9.2% 229
Chow Chow 8.5% 483
Bedlington Terrier 8.5% 117
Eurasier 8.2% 73
Portuguese Podengo Pequeno 7.4% 95
Toy Fox Terrier 6.6% 212
Scottish Terrier 6.5% 446
Lowchen 6.3% 63
Lhasa Apso 6.1% 132
Chinese Shar-Pei 6.0% 367
Shiba Inu 6.0% 1,558
Boston Terrier 5.9% 2,210
French Bulldog 5.8% 1,817
Cardigan Welsh Corgi 5.7% 53
Chihuahua 5.7% 1,446
Norfolk Terrier 5.6% 320
Pug 5.5% 595
Shetland Sheepdog 5.5% 110
Tibetan Terrier 5.4% 185
Norwich Terrier 5.3% 827
Coton De Tulear 5.2% 1,552
American Eskimo Dog 5.1% 98
Petit Basset Griffon Vendeen 4.9% 61
Biewer Terrier 4.7% 150
Dachshund 4.7% 494
English Bulldog 4.6% 1,076
Brussels Griffon 4.5% 89
Bichon Frise 4.5% 2,043
Labrador Retriever 4.2% 909
Silky Terrier 4.0% 200
Poodle 3.9% 2,639
Rat Terrier 3.9% 1,172
West Highland White Terrier 3.8% 419
Affenpinscher 3.8% 264
Schipperke 3.6% 421
Chinese Crested 3.4% 611
Puli 3.3% 184
Cairn Terrier 3.2% 189
Beagle 3.1% 127
Papillon 3.1% 1,546
Siberian Husky 3.1% 64
Havanese 3.1% 4,915
Maltese 2.9% 276
Pharaoh Hound 2.8% 180
Soft Coated Wheaten Terrier 2.7% 256
Bloodhound 2.7% 150
Brittany 2.6% 116
Border Terrier 2.5% 1,585
Italian Greyhound 2.5% 808
Keeshond 2.4% 1,086
Pitbull Terrier 2.4% 127
Miniature Pinscher 2.2% 185
Finnish Spitz 2.2% 89
Havana Silk Dog 2.1% 238
Cavalier King Charles Spaniel 2.1% 5,597
English Cocker Spaniel 2.0% 589
Alaskan Klee Kai 2.0% 406
Cockapoo 1.9% 104
Canaan 1.9% 105
American Hairless Terrier 1.9% 157
Miniature Bull Terrier 1.9% 54
Shih Tzu 1.9% 485
Russell Terrier 1.9% 103
Wire Fox Terrier 1.9% 52
Pyrenean Shepherd 1.8% 111
Norwegian Elkhound 1.6% 63
Cane Corso 1.6% 63
Flat-Coated Retriever 1.5% 2,272
Dogue De Bordeaux 1.4% 210
Bernese Mountain Dog 1.4% 146
Akita 1.4% 956
Boxer 1.3% 75
English Springer Spaniel 1.3% 237
Mixed Breed Dog 1.3% 856
Golden Retriever 1.3% 833
Smooth Fox Terrier 1.2% 247
Finnish Lapphund 1.2% 86
American Pit Bull Terrier 1.2% 248
Rhodesian Ridgeback 1.2% 162
Greater Swiss Mountain Dog 1.2% 498
Australian Shepherd 1.2% 487
Nova Scotia Duck Tolling Retriever 1.1% 277
Great Pyrenees 1.1% 748
Rottweiler 1.0% 609
Black Russian Terrier 1.0% 194
Australian Cattle Dog 1.0% 197
Basenji 0.9% 351
Miniature Australian Shepherd 0.9% 427
Parson Russell Terrier 0.8% 365
American Staffordshire Terrier 0.8% 383
Newfoundland 0.7% 1,900
Kuvasz 0.7% 148
Labradoodle 0.7% 271
Great Dane 0.7% 142
German Shepherd Dog 0.7% 273
Field Spaniel 0.7% 143
Border Collie 0.6% 158
Bouvier Des Flandres 0.3% 344
Mastiff 0.3% 2,693
Miniature Schnauzer 0.0% 164
Briard 0.0% 66
Pembroke Welsh Corgi 0.0% 150
Staffordshire Bull Terrier 0.0% 103
Welsh Terrier 0.0% 75
Belgian Shepherd Tervuren 0.0% 58
Belgian Shepherd Malinois 0.0% 115
Chesapeake Bay Retriever 0.0% 81
Doberman Pinscher 0.0% 63

Related Content

Get Free Quotes!

Compare Quotes From all the Top Companies