What is a luxating patella?

This is a common condition in smaller-breed dogs. The knee-cap (patella) is supposed to sit in a groove of the end of the thigh bone. For some dogs the patella doesn’t sit well in this groove and begins slipping in and out of place. If it gets bad enough, it stays continuously out of place. If left unaddressed, it slowly gets worse and can also lead to other problems in the knee, including a torn cruciate ligament and premature arthritis.
For many dogs, especially early on the disease, they don’t show much lameness at all. But as the condition continues, they may begin to show intermittent lameness which progressively worsens. Then, if they also develop a torn cruciate ligament as a consequence of the luxating patella, their lameness may suddenly worsen cause great pain.
Most of the time, we see cases where the patella luxates to the inside of the leg. We call that a medially luxating patella (MPL). Occasionally, we’ll see cases where the patella luxates to the outside of the knee. We call that a lateral patella luxation (LPL).

How do we surgically fix this problem?

There are different degrees of severity to MPLs and so we must tailor each surgery to each patient. Below, we’ve listed the various common procedures that are done during surgery. These are listed in order of importance and only the most severe cases require all 4.

 

1. Tibial Tuberosity Transposition (TTT): We shift the insertion point of the patellar tendon so that it no longer pulls the knee cap out of place.

 

2. Trochleoplasty: We deepen the groove of the thigh bone so that the patella sits firmly in place once again.

 

3. Lateral Imbrication: We tighten the tissues on the outside of the knee, which have loosened over time.

4. Medial Release: We sometimes need to loosen the tissues to the inside of the patella, which have tightened up over time.

MPL Surgery Example
This was a 2 year old Boston Terrier that came in with a grade 3 out of 4 patella luxation. Grade 3 is where the kneecap generally sits out of place at all times but can be momentarily pushed back into place. Grades 3 and 4 MPL always require surgery to bring back good mobility. Here, we deepened the groove of the femoral trochlea and repositioned the tibial tuberosity so that the patella, tendon and muscle were in proper alignment to the femur.

Before

AFTER

What Does This Cost?

1)  The out-the-door cost is $4,000 per affected leg.  The exact cost is affected by the size of the pet and the severity of the problem.

2)  Our quote includes all necessary expenses for the day of the surgery and medicine that we would send you home with.  What is not included would be any complications that might develop due to poor confinement, or the patient licking at their incision - causing an infection.  Also not included are any exam fees and tests for follow-up visits occurring 2 weeks beyond the surgery date.