Knees of horses and cows give clues to human osteoarthritis

The knee joints of horses and cows are leading to better understand of human knee weakness, in research from the University of Bath.

The team involved says their study could give medics a better understanding of osteoarthritis in the knees of humans.

“For human knees, a common failure is osteoarthritis, which is the result of degradation of cartilage within the knee joint,” says Prof Richie Gill, lead author. “The cartilage is needed to provide a low-friction, self-lubricating surface that can bear loads and permit movement. When this breaks down, the sufferer will experience pain and a loss of movement.”

Relatively little is known about how biochemistry and genes of the materials that make up cartilage contribute to the workings of the joint.

“Understanding the mechanical properties of cartilage within the knee isn’t trivial,” says Prof Gill. “Traditionally, to do this you’d need to surgically remove significant amounts of cartilage from the knee, and this would require the use of cumbersome equipment. There is a clear need to develop a simple technique that will allow the testing of small tissue samples.”

The research team at Bath has developed such a technique (based on the shearing of small biopsy samples) – Dynamic Shear Analysis – using it to compare the knees of horses and cows.

“Dynamic Shear Analysis can give us detailed measurements of the behaviour of a material. We have been able to use this method to test the collagen network that makes up cartilage,” Prof Gill explains. “Our method enabled us to study the makeup of cartilage in the knees of cows and horses, rather than just knee morphology – how the knee joint is formed. Overall we saw highly significant differences between the cartilage of horses and cows. Horse cartilage is thicker, compresses less and has a greater resistance to deformation – it almost certainly developed this way to allow for the speeds at which horses travel, and increased pressure on the knee joint.

“Our observations have implications for the study of human knee cartilage and its diseases. Evolutionary pressures in human knees may have increased our knee range of motion, but not driven significant change in cartilage material properties. The technique of DSA could offer a new, powerful means to understand osteoarthritis and classify knee joint failures.”

To read the full research click here.