3D-printed practice parts turn patients inside out

Surgeons can now see and handle the body parts they will be repairing in the operating theatre before making a single cut, thanks to 3D-printed models. The parts shown here were all used in complex reconstructive surgery on real patients. They were produced by Cavendish Imaging in London using detailed data from three dimensional CT or MRI scans. "We're making physical what was virtual," says Andrew Dawood, the company's founder. "It's something in our hands that's tactile and tangible." Andy Coghlan

                                                                           

This is the 3D-printed model of the facial bones of conjoined twins Rital and Ritag Gaboura, and the open

In 2011, British doctors separatedthe twins. The surgery was especially tricky because, unusually, the join was between the tops of the children's heads, raising the risk of brain damage or serious trauma during separation.

The lead surgeon, David Dunaway, of London's Great Ormond Street Hospital, said that being able to recreate the corridor through 3D printing was the key to success. It allowed his team to see the shared internal blood vessels exactly as they would be encountered during the operation, and to experiment with the best and safest way to separate them.

corridor of the skull by which they'd been joined since birth.

In 2007, a Nigerian bank manager had most of his lower jaw shot away by robbers in Lagos. With the help

The image shows a 3D model that recreates the full jawbone, based on the parts of it that survived the shooting. From this, maxillofacial surgeon Iain Hutchison of St Bartholomew's Hospital in London was able to make sure the jawbone had the exact dimensions 'needed to fit. The part that looks like a bicycle chain is made of titanium and fixes the jaw to the man's face

of 3D printed models, surgeons were able to make him a replacement out of one of his shoulder blades. They even managed to give him a set of functioning, implant-anchored teeth in the same operation, the first time this has been possible.

3D-printed models like the one shown next to this skull are particularly helpful when a medical condition has destroyed the symmetry of a patient's body. They can serve as a template for the repairs based on the intact side.

A patient whose face was disfigured by a huge bone growth on one side of her face was given a more

For another patient, a benign brain tumour had pushed up an area of her skull. Normally, two surgeries are necessary to remove the tumour and then fit a titanium cap to cover the resulting hole. In this case, a perfectly matched, 3D-printed plastic template and cap allowed Joan Grieve of the National Hospital for Neurology and Neurosurgery in London to cut and seal the opening in a single surgery.

symmetrical look with such a template. A nylon model of her unaffected cheek gave the surgeon, Jonathan Collier of the Chelsea and Westminster Hospital in London, a guide for drilling the surplus bone away without injuring the tissue below.

           

Above the metal hip joint nestled in this 3D-printed pelvis is a "pseudotumour" – a benign growth that can be painful and sometimes requires surgery. 

"This model shows clearly how the tumour can create pressure on major blood vessels," says Reshid Berber of the Royal National Orthopaedic Hospital in London, who uses such models to prepare for joint replacement surgery.

Source :newsscientist.com