**UPDATE 2/2011 – The information below regarding UPenn Veterinary’s stance on TPLO surgeries is no longer correct. UPenn is, in fact, performing TPLOs on dogs. I will keep up the link to the article below discussing their previous stance toward TPLO so that people may have access to all of the information. Everything else in this post regarding the way the extracapsular repair surgery for dogs is performed remains correct and up to date.
In the extracapsular imbrication, also known as the traditional method and lateral fabellar surgery, your dog will have a strong leader line placed within the knee to provide stabilization. Some veterinarians will only perform this procedure on small dogs and cats, while others will use the technique on dogs of all sizes. There is no definitive study evidence showing that tibial plateau leveling osteotomy, or TPLO, is superior to the extracapsular method in large dogs, in fact, the University of Pennsylvania, one of the nation’s leading veterinary hospitals, will not perform the TPLO procedure as the cost/risk risks do not outweigh the benefits. For more information see the article here – University of Pennsylvania Veterinary Hospital – TPLO Surgery
Extracapsular stabilization involves stabilizing the stifle using some means external to the joint capsule. During the first part of the procedure a 3 to 5 inch incision will be made through which the surgeon will have access to the stifle. First, the damaged cranial cruciate ligament is completely removed. Second, the veterinarian will examine the mensicus to determine whether or not there has been any injury or deterioration of the tissue. At this point the doctor my decide to remove the meniscus depending on the amount of injury, only removing the meniscal tissue that has been damaged. A partial meniscectomy is preferable over a complete meniscus removal, and dogs left with some healthy meniscus intact tend to develop less arthritis later in life.
During the extracapsular imbrication a large, non-absorbable suture is placed in a figure eight pattern within the structure of the knee. The leader line is placed around the lateral fabella through a hole in the tibial crest, mimicking the course of the CCL and preventing forward movement of the tibia, also known as the clinical drawer sign. The monofilament nylon leader line has a range of tensile strengths, and depending on the size of your dog, your veterinary surgeon will select a size between 40-100 pounds. Over time scar tissue will develop on the side of the knee joint where the large suture was placed, providing stifle stability in the absence of the canine cruciate ligament.