Technique Used in Human Ankle Injuries Modified to Treat Dogs' Knees
MU veterinary clinician-scientist develops a minimally invasive method to treat torn ligaments
June 16, 2008
Story Contact: Kelsey Jackson, (573)882-8353, JacksonKN@missouri.edu
COLUMBIA, Mo. – A common sports injury in human knees is even more common in dogs. Each year, more than one million dogs suffer from cranial cruciate ligament (CCL) deficiency, which is comparable to the anterior cruciate ligament (ACL) injury in humans. The common method of treatment by many veterinary surgeons involves cutting the tibia bone to stabilize the CCL-deficient knee in these dogs. Now, a new minimally invasive technique with less severe complications than previous methods has been developed by a University of Missouri College of Veterinary Medicine researcher.
Unlike humans, CCL injuries in dogs typically do not occur because of a single trauma to the knee but are the result of a degenerative process that leads to early and progressive arthritis. For this reason, and the unique biomechanics of the canine knee, techniques used to repair the injury in humans do not work well for dogs. The new technique, known as Tightrope CCL, is modified from a technique used in human ankles and allows placement of a device that stabilizes the CCL-deficient knee through bone tunnels drilled using very small incisions. MU veterinarian James Cook worked with Arthrex Inc. from Naples, Fla., to develop and test the Tightrope device for dogs.
“Other current techniques require major surgery that involve cutting the bone, which can potentially lead to severe complications, such as fracture, implant failure and damage to the joint,” said Cook, professor of veterinary medicine and surgery and the William C. Allen Endowed Professor for Orthopedic Research. “This new technique is minimally invasive, relatively easy to perform and cost effective compared to other techniques. The dogs in the preliminary trial study experienced fewer and less severe complications with outcomes that were equal to or better than those seen with the bone-cutting technique.”
Cruciate ligament tears are five times more common in dogs than humans and cost U.S. pet-owners more than $1.3 billion each year. The new technique is not for every dog. Because surgeons must be able to drill tunnels in the bone, dogs must weigh at least 40 pounds for the Tightrope CCL method to be feasible. In addition, dogs that cannot follow a physical rehabilitation protocol after surgery and dogs with limb deformities are not candidates for this technique. The 10- to 12-week rehabilitation period is very important for any surgical technique for CCL deficiency in order to optimize successful return to pain-free function and reduce complications, Cook said.
“The times the Tightrope CCL technique has failed are when owners did not give their dogs the full rehabilitation period and let their dogs run, play or traumatize the joint before the knees were ready,” Cook said. “A successful operation is dependent on postoperative care so that the dog can heal well and build muscle for long term function. The Tightrope CCL technique is designed to allow this to happen with less surgery and less risk of a major problem arising, and so far, it has been successful.”