If your dog has ruptured its cranial cruciate ligament and you have been presented with only one surgical option (TPLO or TTA) and logistically can not afford these surgeries, there may be an alternative procedure that can significantly improve or resolve the limping and pain. It is called the extracapsular repair/lateral suture technique.
Extracapsular repair/lateral suture
The least invasive procedure for dogs and their owners is the extracapsular repair or lateral suture technique. This repair involves the placement of non-absorbable suture in a fashion that mimics the function of the cranial cruciate ligament. Depending on where you and your pet received a consultation, the cost of the extracapsular repair can vary between 50-75% less expensive than a TPLO or a TTA.
There are pros and cons of all these different procedures. The extracapsular repair works extremely well in dogs that weigh less than 40 pounds. However, the largest patient that Dr. Kim cared for with a rupture cruciate ligament is a crazy hyper 90 pound boxer that did extremely well after the procedure.
In smaller dogs, this procedure will likely be performed only once. In larger dogs, there is a possibility that the procedure may have to be repeated in several years to replace the suture due to stretching.
What is the cruciate ligament?
There are two cruciate ligaments in dogs, cats, and people. The cranial cruciate ligament (same ligament to the anterior cruciate ligament in people) and the caudal cruciate ligament (same ligament to the posterior cruciate ligament in people). The cruciate ligament are present within the knee. The cranial cruciate ligament prevents the tibia (shin bone) from displacing forward. Rupture of this ligament causes only a 1/4 - 1/2 inch abnormal movement of the shin bone. Albeit a small movement, this abnormal movement is likely the cause of pain.
Other causes of pain include meniscal tears, excessive inflammation, abnormal tissue, or even autoimmune disorders (similar to rheumatoid arthritis in people).
How is a ruptured cranial cruciate ligament diagnosed?
Speak with your family veterinarian for definitive diagnosis and care. Typically, a veterinarian will gently palpate the knee to determine if there is an abnormal movement (cranial drawer/tibial thrust). Your veterinarian will also palpate for excessive swelling, pain in abnormal parts of the knee, or abnormal bone growths . Radiographs may be taken to verify that other causes of lameness and pain are not present (infection, cancer). These steps are often the only steps required to define a cranial cruciate rupture in your dog. Other modalities to verify rupture may include arthroscopy (anesthetized camera evaluation) CT scan, or MRI. These procedures may be deemed necessary by a specialist if palpation and radiographs are inconclusive.
How is a ruptured cranial cruciate ligament repaired?
The cranial cruciate ligament is not repaired. Due to the nature of ligaments (fibrous tissue, low blood flow), the cranial cruciate ligament will usually not heal to 100%. Either the action of the cruciate ligament is mimicked with a surgical technique or the need for a cranial cruciate ligament is removed via surgical technique.
Ask your family veterinarian to discuss suitable options for you and your dog.
Extracapsular repair/lateral suture
The least invasive for dogs and their owners is the extracapsular repair or lateral suture technique. This repair involves the placement of non absorbable suture in a fashion that mimics the function of the cranial cruciate ligament.
TTA (tibial tuberosity advancement surgery)
This procedure involves cutting the tibial tuberosity (the very front of the shin bone), placing a metallic bone plate and moving the insertion of the patella ligament . Subsequently, the patellar ligament in the new position mimics the cranial cruciate ligament.
TPLO (tibial plateau leveling osteotomy)
This procedure involves cutting around the articulatory surface of the shin bone. The articulatory surface is then rotated in a way where the cranial cruciate ligament is no longer required (attempting to make the patient's knee function more like a human's knee).
Human analogies -
The placement of cadaver ligament has been met with limited success in veterinary medicine. Other methods to correct cranial cruciate ligament (ACL) ruptures in human unfortunately do not translate well to veterinary patients due to how dogs and cats walk (with knees always bent and on their toes).
The placement of a splint has varying success in veterinary medicine. To the author's knowledge, there is one company that can be found on the internet to custom make splints. The use of splints may have good use to partial tears of the cranial cruciate ligament. However, the technology of splint for the treatment of cranial cruciate ligament rupture is still fairly new and may hold a place in the treatment of cranial cruciate ligament ruptures in the future.
There are pros and cons to all these different surgeries. Speaking with your family veterinarian to discuss the pros and cons for you, your family, and your pet is the best thing to do.
At South Orange County Animal Hospital, we offer the extracapsular repair/lateral suture technique for our owners and patients due to the shorter post operative care and the decreased financial cost to families. This technique is appropriate for the right type of dogs and owners. The specialist hospitals that our hospital refers orthopedic patients to include Veterinary Surgical Specialists and Southern California Veterinary Specialist Hospital.