By Boulder Dog Food Company
A rupture of the cranial cruciate ligament (CCL) of the stifle or rear knee joint is one of the most common injuries seen in dogs. The standard treatment for these CCL tears has been surgery. Most veterinarians continue to believe that, while other options have been developed, surgery remains the preferred treatment. Moreover, they believe that time is of the essence in scheduling a surgical procedure in order to improve the odds for a successful recovery. Otherwise, inflammatory changes in the joint will result in arthritis and a permanent degenerative condition.
However, there are some veterinarians who believe that less invasive surgical procedures along with non-surgical options should be considered. Dr. Narda Robinson DVM, who oversees complementary veterinary education at Colorado State University, is a spirited advocate for alternative treatment. She exhorts her colleagues to “stop cutting cruciates at least until patients have undergone a month or more of conservative care.” She believes that “the chronicity and persistence of canine cruciate disease argues in favor of a long-term, rehabilitative and integrative approach, not for bone saws.” Dr. Robinson claims that the ideal treatment for CCL injuries has not yet been determined and that more research and clinical trials are needed. Moreover, she affirms that since rehabilitation and pain control are usually necessary regardless of whether a dog will undergo surgery, it makes sense to start with these things first to see if the surgery can be avoided.
The Veterinary Teaching Hospital at CSU takes a different view and believes that a properly diagnosed CCL rupture calls for a speedy surgical option. The two broad categories of surgeries attempt to 1) change the geometry of the stifle or knee joint so that the ligament is no longer needed or 2) replace the damaged ligament itself. In the latter category, the repair can be done inside the knee joint with the body’s own material or outside the knee joint with synthetic material. As of now most of these repairs are extracapsular or outside the knee joint but researchers are working on using synthetic material inside the knee joint to improve the outcome for intracapsular repairs.
The so-called gold standard of surgical procedures, the Tibial Plateau Leveling Osteotomy (TPLO), is in the first category and is one of the most widely used surgeries for CCL ruptures. It requires cutting and re-orienting the plateau or top of the tibia and stabilizing it with a plate and screws. A variation of this surgery is the Tibial Tuberosity Advancement (TTA) where the tuberosity or front edge of the tibia is cut and the plate is attached along the front of the shin bone. These surgeries are expensive and involve extensive post-operative care.
At CSU, the cost for pre-operative exams, x-rays, implant, surgery and post-surgical pain management for either the TPLO or the TTA is estimated at $3000-3200. Postoperative care is also critical and mandates a strict restriction of activity for approximately four months. Any premature or excessive activity risks re-fracturing the bone prior to healing.
Surgeries which fall into the second category, attempting to replace the damaged ligament, are somewhat less invasive and more traditional. The Extra-capsular Suture Stabilization (also called the Ex-Cap suture) replaces the damaged ligament with a heavy type of nylon fishing line in a suture designed to stabilize the relationship of the tibia to the femur. A somewhat similar surgery is the so-called “Tight Rope” procedure where specialized sutures are affixed to anchors drilled in the bones above and below the knee joint, thereby stabilizing the joint.
While these external capsular repairs have been improved upon in recent years and are less expensive, they are primarily recommended for small breeds or for sedentary older animals. The TPLO and TTA are recommended for younger more active dogs given that the skeletal structure of the dog knee is under a tremendous mechanical stress even during moderate activities.
If surgery is needed, Dr. Robinson argues that the external capsular repair surgeries are far les traumatic than the TPLO and TTA while having a better safety record and fewer complications. However, she also believes that non-surgical options are essential for those people unwilling or unable to allow their dogs to have any surgery at all.
Non-surgical options include rest and restricting activity for the injured canine, perhaps accompanied by weight loss if the animal is somewhat overweight. Anti-inflammatories are often given to reduce swelling. Rehabilitation therapy can also help the animal recover but most specialists believe that it belongs in a post-operative setting rather than as an option to surgery. A recent development is the advance in custom knee braces although, again, many would argue that bracing is not a long-term solution for an active dog.
Prolotherapy or “regenerative injection therapy” is another nonsurgical procedure being studied for both humans and canines. It involves injecting an irritant solution into the knee joint or damaged ligament to relieve pain. Injections are repeated at regular intervals. Proponents of prolotherapy are also examining the possibility of using growth factor stimulants to induce a regeneration of tissue. The outcome of this research remains unknown.
The Veterinary School at CSU advises that without surgery “the symptoms of lameness and pain may subside with time, (but the ability) to return to normal activity levels will often be limited by the progression of osteoarthritis.” They warn, “It is important to point out that, in general, the earlier surgical therapies are performed, the more effective they are; thus, a ‘wait and see’ approach to non-surgical management based only on wishful thinking is seldom advised.”
While a CCL tear in canines is often compared with the anterior cruciate ligament (ACL) injury in humans, there are important distinctions. Unlike humans, the tear might be the result of a long slow degeneration taking place in the ligament rather than a sudden trauma to a healthy ligament. And, according to Dr. Tom Suplizio DVM, “Unlike their human counterparts, dogs with even partial CCL tears generally will benefit from surgery. This is largely due to the unique forces that the dog’s stifle undergoes that differs from the vertical position of our knees.” In his argument, Dr. Suplizio warns that “without surgery, chronic instability leads to arthritis and meniscus tears, and puts the opposite knee at risk of injury because of overcompensation. In fact, even with surgery, a majority of dogs that rupture their CCL will rupture the ligament in their opposite knee within a year or two.”
While a conservative approach might be a reasonable response for some injuries, delay in treating a CCL rupture has 10 possible consequences according to the Editorial Blog of Veterinary Practice News:
Degenerative joint disease (DJD)
Decreased range of motion
Contralateral CCL tear
Future problems with gait and posture
Although there may be differences of opinion about the treatment for CCL tears, everyone agrees on the need for preventive measures. The chief way to avoid a CCL injury is to protect canines from becoming overweight. Obese dogs are four times more likely to rupture a cruciate as non-obese dogs, according to the Journal of Small Animal Practice.
Dr. Suplizio cautions that while there is no way to completely prevent CCL injuries, steps can be taken to minimize the chances of occurrence, advising that “keeping pets in ideal body condition, exercising regularly, and avoiding play that encourages high jumping will help to reduce the risk of CCL damage.”
10 Deadly Sins of Untreated ACLs” Dr Phil Zeltzman, DVM
Veterinary Practice News Editorial Blog (July 26, 2010)
“Cruciates: Less Cutting, More Self-Repair” Dr Narda Robinson, DVM, Veterinary Practice News (Posted online November 15, 2013)
“Treatment Options for Cranial Cruciate Ligament Injury/Disease of the Dog Knee” Colorado State University, Veterinary Teaching Hospital
“Questioning Canine Cruciate Ligament Surgery” Dr Narda Robinson, DVM, Veterinary Practice News (Posted online October 15, 2012)
“Cranial Cruciate Ligament Tear, a Common Pet Injury” Drs Tom and Tara Suplizio, DVMs, The Daily Sentinel (April 13, 2014)
“Changing Views on CCL Repair” Dr Narda Robinson, DVM, Veterinary Practice News (April 23, 2014)