Pros and Cons of Luxating Patella Surgery

The procedure is used to address luxation, or the kneecap "popping out" (called the patella). A luxating patella is triggered by a congenital abnormality that exerts excessive stresses on the kneecap, causing it to move out of its usual groove (called the patellar groove). Patellar luxation can develop in a variety of degrees or grades:

Grade I – the patella suddenly slips back into position

Grade II - the patella periodically slips out of place but maybe manually repositioned.

Grade III - the patella is frequently out of position but can be manually repositioned.

Grade IV - the patella is permanently dislocated and cannot be repositioned.

Numerous techniques are available to maintain the patella's groove. Whether or not an MPL can be fixed surgically will be determined by the grade of displacement and the underlying structural defects that are causing it. To rectify the problem, a mix of procedures may be required in some circumstances. Certain methods target the soft tissues that surround the patella, while others target the bones. In most canines, the trochlear groove, in which the patella fits in, must be extended to better hold the patella. This is achieved through trochlear wedge or block recession or resection. When the tibial crest attaches to the patellar ligament in the wrong place, a cut is made to reposition the bone so that the patella can be aligned correctly in the trochlear groove. Following that, pins are employed to hold the bone in place.

Malformed patellas and their attachments to the bone can cause the femur to twist in some dogs as they grow. The femur may also need to be corrected in these cases. 

Depending on the procedure, MPL surgery costs anywhere from $1,200 to $2,500. The exact cost of surgery depends on where you live and who performs the operation. The veterinary surgeon and hospital where the surgery takes place must be board-certified. Costs usually include not only the surgery, but also tests, anesthesia, and post-operative care. Physical therapy may also be provided after surgery in some hospitals.

Pros and Cons of Luxating Patella Surgery

Patella luxation may require surgery for some dogs, especially those with severe cases (grades 3 and 4). Your veterinarian will help you decide which of the surgical options is best for your dog. Every surgery has pros and cons, and certain patellar procedures can only be handled by a veterinarian at a referral center.

Dogs with recurrent or persistent lameness or other injuries to the knees caused by luxating patellas should undergo surgery. A grade I patellar luxation does not often require surgery, while grades II-IV do. There are three main steps in the procedure:

• The patellar ligament is moved to the proper position at the point of attachment to the shin bone.
• It is also designed so that the patella stays in place by deepening the groove in the femur.
• The capsule is tightened around the joint. As the patella slips, it stretches the joint capsule. When it's tightened, the patella is less likely to luxate again.

It is also possible to place an implant inside the knee, making it difficult for the patella to slip over.

Recovery is often rapid after surgery, especially with appropriate pain management.

Complications are always possible with any surgery. MPL surgery is likely to encounter more infections than other complications. It is more likely that a luxation that is of high grade before surgery will re-luxate after surgery, making another operation necessary. 

Exercise and rehabilitation should also be limited accordingly to avoid compromising the repair. It is likely that arthritis will develop in the affected joint after any orthopedic surgery, although earlier diagnosis and treatment can slow the progression of the condition.