Medial patellar luxation is a condition in which the kneecap (patella) pops out of its groove. It can pop to the inside of the knee or the outside of the knee making the knee quite unstable. This condition is often diagnosed in small breed dogs, frequently effecting both rear legs and can be either traumatic or congenital. Congenital MPL is far more common and is most often the cause of MPL in small dog breeds and in cats. In large breeds, MPL can be due to a congenital problem but can also occur secondary to trauma. MPL occurs most commonly in breeds such as Yorkshire terriers, Maltese, Papillion, miniature poodles, but also can be seen in Labrador retrievers, Great Pyrenese, and other large breeds.

The condition is usually first detected in 6-12 month old puppies and the condition can worsen over time from a mild and only occasionally popping patella to a chronically luxated patella that cannot be put back into the femoral groove anymore. This is called a Grade 4 medial patellar luxation.

What does the Surgery entail?

The repair consists of several steps, in which the kneecap is put back in to the groove, the groove is deepened and the surrounding soft tissues and bone are also altered to secure the patella within the groove. Sometime the tibial crest (front section of the shin bone) is transposed to a slightly different location and secured with tiny pins. Most dogs return to full use of the limb very quickly.

What is the Aftercare?

Strict rest is required following surgery to prevent the patella from reluxating during the healing process. Initially, there should be no running, jumping, or playing. After a gradual increase in activity, full function is allowed by 2 months in most cases.

Are there any Risks or Complications?

Most complications are minor in nature. Reluxation is rare but may occur and often requires an additional surgery. This is of most concern during the first 2 months following surgery, especially in cases that had a severe grade of luxation prior to surgery. If pins had to be used to transpose the tibial crest, these may need to be removed in 3-12 months. Some dogs act "allergic" to the metal.

There are few risks or complications with the MPL surgery. Be sure to discuss them at your appointment. We would like to have current, pertinent blood work to assess the risk for general anesthesia. The risk is usually very low for healthy animals with normal blood work. It is further reduced by local pain control during anesthesia, which is accomplished by epidural anesthesia.

Overall, some pets recover very quickly with little need for owners' assistance, but other animals need intensive physical therapy. Lean and fit animals tend to recover quicker than overweight and weaker pets.