From affordable prosthetics to replacement turtle jaws, we’ve long been impressed by the medical applications for 3D-printing. But in a world first, a 54-year-old man in Spain has just received a new sternum and rib cage, thanks to a titanium implant printed by scientists in Australia.
Damage from chest wall sarcomas, cancerous tumors that grow around the rib cage, is notoriously tricky to repair with prosthetics. This all boils down to the fact that each patient’s sternum and connecting bones have their own unique geometry. No two human bodies are exactly alike, so surgeries past often involved fitting broad, flat implants to the chest, which can come loose over time, and pose a high risk of complication.
So when a patient at Spain’s Alamanca University Hospital required a full sternum replacement, his surgeons knew they needed to think outside the box. The team turned to Melbourne-based medical device company Anatomics, and together came up with a long-awaited solution: a completely customizable 3D-printed chest implant that could replicate the intricate structures of the sternum and ribs.
“It would be an incredibly complex piece to manufacture traditionally,” says Alex Kingsbury, who printed the implant at CSIRO’s additive manufacturing lab. “And in fact, you know, almost impossible.”
Using high-resolution CT scans, the team was able to create a 3D reconstruction of the patient’s chest wall and tumor, allowing his surgeons to plan the removal with extreme accuracy, and Anatomics to design an implant that would fit like a glove.
“As you could imagine, the [standard] 3D printer wasn’t quite up to the challenge,” says CSIRO. “Instead, we relied on our $1.3 million Arcam printer to build up the implant layer-by-layer with its electron beam, resulting in a brand new implant which was promptly couriered to Spain.”
Electron-beam “printers” don’t extrude material like you might imagine, but rather work by melting fine-grain particles of metal, here surgical titanium, using an 3,000-watt electron gun. Titanium doesn’t even begin to melt until it reaches 1,650 degrees Celsius (3,002 degrees Fahrenheit), so you can see why all that energy is necessary. Layer upon layer of particles are melted on top of each other, forming the desired shape from the ground, up. It’s the same process that was used to make a mini jet engine back in May.
“We were able to create a design that sits over the bones, and you screw through it. So it’s attached really securely,” says Kingsbury. The patient was discharged just 12 days after surgery, and appears to be recovering well.
IMAGES: CSIRO, Anatomics, NetFabb