Researchers at the UW-Madison School of Veterinary Medicine have recently invented a device that may help prevent the rupture of a ligament in dogs, preventing arthritis in the knees.
The device measures the amount of looseness in the cranial cruciate ligament-the major stabilizer of the knee joint and equivalent to the anterior cruciate ligament in humans. Too much looseness, a problem most common in larger-breed dogs like golden retrievers and labradors, can lead to rupture of the ligament.
\We would like to use this device in dogs that are having knee problems,"" said Mandi Lopez, a veterinary surgeon, SVM researcher and co-inventor of the device. ""The rupture of the cruciate is a very, very common problem. It's the arthritis that comes afterwards that's painful.""
Surgeries can repair the cruciate ligament after it ruptures, Lopez said, but it is not as effective as the original. Ultimately, the dog develops arthritis.
The new device, she said, could prevent this by catching a weakened cruciate ligament before it ruptures. Pre-emptive surgery could repair the ligament and restore its function.
To determine the weakness of the ligament with the device, a veterinarian straps a dog's leg to the platform, composed of two moving pieces. X-ray images of the knee under different pressures are superimposed to measure the amount of movement in the joint.
With a normal cruciate ligament, Lopez said, the bone will only move a little. But when the cruciate is ruptured it juts out.
Previously, detection was done by hand. Veterinarians had to trust in the feel of the bone, a procedure that had limits, said Mark Markel, veterinary surgeon and co-inventor of the device with Lopez and instrument specialist William Hagquist.
""This device allows you to detect 0.1 millimeters of movement,"" Markel said. ""That's 30 times better than what you can do by hand.""
It is even a bit more precise than what is used in humans, he said.
Studies must first determine how effectively the device prevents rupture of the cruciate in dogs, he said, but they also hope to be able to adapt it for other animals in the future.
The device has been patented by the Wisconsin Alumni Research Foundation, but is not currently being marketed.
