Japan Begins Trial of Cow-Tendon Material for Knee Ligament Repair

Japanese researchers have begun a clinical trial of a medical material derived from cow tendons for anterior cruciate ligament reconstruction. The work is led by Kiyotaka Iwasaki, a professor at Waseda University, together with researchers from Tokyo Women’s Medical University.

They confirmed safety of the material in surgeries on seven patients before starting the randomized controlled study at six institutions across Japan.

The trial assigns 57 patients needing ACL reconstruction to either the experimental cow-derived material or a transplant of their own tendons taken from other areas. Standard treatment currently uses tendons from the patient’s hamstring or knee. Removal of those tendons can cause pain at the harvest site and may reduce muscle strength.

Cow tendons offer suitable thickness and strength, but untreated tissue can provoke immune reactions such as inflammation. The researchers apply a decellularization process that uses a pulsating pump to circulate a cell-breaking solution deep into the tissue while microwaves accelerate removal of cellular components.

The resulting tissue is then freeze-dried and sterilized while retaining mechanical strength.

,” Iwasaki said. ” Iwasaki founded CoreTissue BioEngineering in 2016. The researchers aim to obtain regulatory approval for the device in Japan in 2029 and are preparing a clinical trial in the U.S. In Japan, 20,000 to 30,000 people, typically high-school or college athletes, suffer ACL injuries each year, and about 15,000 undergo reconstruction surgery.

More than 200,000 people are affected annually. One researcher hopes to extend the material to reconstruction of other ligaments in the knee as well as in the ankle and inner elbow.