I saw a science program about finding a substitute for bone. What’s wrong with using the real thing? Why do we need a substitute?

There are many possible uses for a bone substitute. For example, people with weak or brittle bones from osteoporosis or other bone diseases don’t heal well when they fracture. A bone-stimulating substance or bone substitute could be injected into the break and speed up healing.

Spinal fusions have problems because in up to 40 per cent of cases, the two bones form a false joint. This creates movement at a place where no movement is desired. A substance that could fuse stronger than natural bone is needed in these cases.

Harvesting bone for use by the patient is painful, requires a separate operation, and increases the risk of infection. Other problems such as blood loss, numbness, and injury to the nearby blood vessels can occur.

Other uses for bone substitute may become apparent once it’s available for use.