Serious fractures, such as this broken head of the thigh bone, or femur, may one day be remedied by an infection of bone-growing compounds. Pins, shown in white, secure the broken head to the long thigh bone
Broken bones mend only if the have an adequate blood supply. For this reason a few of the body’s bones will never med if they break. Sometimes, a broken bone needs encouragement to heal. That is one reason why surgeons graft onto a broken bone a piece of bone taken from another part of the body, usually from the hip or ribs.
The graft, secured with screws or wires, provides a protein that stimulates new growth. Eventually the graft itself dies, but it provides a framework on which new bone can grow. Similarly when bones have degenerated, surgeons sometimes implant an artificial material, a kind or ceramic, to form a base for natural bone.
The ceramic has one problem: it is not porous, so the new bone has to grow round the implant instead of inside it, which would b more desirable. Now scientists have discovered a natural implant material that is porous, with a structure closely matching that one of human bone. It comes from the skeletons f sea creatures – urchins, coral and some algae.
The skeletons are made of calcium carbonate, which would break down in the human body but they can be converted into chemically stable calcium phosphate. Also they provide moulds from which to cast an improved from artificial implants. There are always body wonders.