The artificial bones created from an inkjet

The technology creates perfect replicas of bones that have been damaged and these can then be inserted in the body to help it to heal.

The process will revolutionise bone graft surgery, which currently relies on either bits of bone taken from other parts of the body or ceramic-like substitutes.

More follows...

Professor Jake Barralet of McGill University in Montreal, Canada, explained: "The "paper" in our printer is a thin bed of cement-like powder. The inkjets spray the cement with an acid which reacts with it and goes hard.

"That deals with one layer. Then new layers of fresh powder are sprayed on top, and the layers build up to the shape we need."

It takes only ten minutes for the printer, which is the size of about three filing cabinets, to print a typical bone graft.

The printed graft acts as a bridge to allow the body to replace the damaged section with new bone. Crucially, the substance created by the printing process contains the same building blocks as real human bone, allowing the graft to eventually dissolve harmlessly into the body.

The sections made by the printer are so precise that spaces can be left to encourage the regrowth of tissue and blood vessels through the graft, mirroring the make-up of normal bone.

Professor Barralet said: "The holes in the bone graft will affect how new bone grows into the graft.

"You can design it so you encourage it in a particular direction, to get different tissue repair. It is mainly useful in areas where you need a very good sort of fit, like cosmetic surgery or reconstructive surgery, or in the spine where you don't want to be playing around to get something to fit.

"We're a long way from seeing this used in a hospital setting, but it's an important first step."

A team of scientists at Manchester University led by Professor Brian Derby are working on a similar printing method to make sheets of artificial skin.