Bone marrow is the soft, spongy substance that fills the inner cavities of bones where blood is produced. Tiny spaces in the bone marrow hold blood and stem cells, the primitive cells that are able to grow into various types of blood cells. Under certain conditions, some of these stem cells can also create new tissue like bone, cartilage, fat and blood vessels.

Bone marrow concentrate (BMC) is made by first collecting bone marrow aspirate from a large bone such as the pelvic bone.