MIT Technology Review recently profiled a special material designed by Cartilix out of of Foster City, CA, that helps with bone marrow clotting during knee-cartilage repair surgery.
During microfracture, a surgeon uses a special awl to drill a series of tiny holes into the bone underneath the area of missing cartilage. Bone marrow containing stem cells seeps into the damaged area and forms a clot. The clot releases stem cells, which differentiate into cartilage cells and gradually form new tissue. However, because the new tissue is scar cartilage, not true cartilage, it may not have the same durability and strength as the original tissue–a likely contributor to the high failure rate of microfracture.
ChonDux consists of a hydrogel made of polyethylene glycol–a polymer commonly used in a variety of medical products–and a bioadhesive to keep the hydrogel in place after injection. First, the surgeon coats the inside of the cavity where the cartilage is missing with the bioadhesive and then, as in microfracture, drills tiny holes into the bone next to the cavity. Then the surgeon fills the empty space with the hydrogel and shines UVA light on the material, which causes the polymer to harden from a viscous liquid into a gel.The blood clot that forms from the microfracture then gets trapped in the hydrogel.