Numerous products exist that utilize placental tissue that would be otherwise discarded. These products are primarily delivered via injection. Placenta-derived tissues include: the amniotic membrane, the chorionic membrane, the amniotic fluid, the umbilical cord, and the blood from the umbilical cord. Placenta-derived products are composed of one or more of these tissue types and/or the matrix secreted by any of these cells. Placenta-derived products have commonly been used in ligament and tendon injuries of the foot and ankle, but they have also been used for conditions like knee osteoarthritis. They are thought to have regenerative properties, though this has yet to be proven. Placenta-derived products are not covered by insurance or Medicare.