3D Printing Human Vertebrae

A surgical team in Australia has implanted the world’s first 3D printed vertebrae.

by Eric Butterman
May 15, 2017

The vertebrae are among the most delicate parts of the body. One small problem can lead to a lifetime of pain, perhaps even being confined to a wheelchair. But, when the problem involves the extremely rare cancer chordoma, the results can be fatal.

Neurosurgeon Ralph Mobbs was once faced with operating on a patient with the ailment, and chose a 3D printed implant for this potentially life-altering surgery. There’s pressure to begin with when someone’s future may hang in the balance, but the pressure is even greater when it’s the world’s first vertebrae implantation.

“3D printing is at the forefront of medicine, where it can do everything from something minor to even saving a life,” Mobbs says. “I’m a big proponent of it for certain situations and here was a chance to put it to work for someone who needed this badly.”

Marrying Material and Body

Mobbs, who works at The Neurospine Clinic in Sydney, Australia, explains that attempting to remove the cancer is only part of the battle. “It’s a very complicated area. After taking the tumor out, there’s the reconstruction of the hole you make. It’s difficult to replace,” he says. “The reconstruction options were never good in the past and had poor outcomes. Printing a vertebrae that was custom was a route which could have strong success, but you need material that will marry with the human body and be strong enough to have the biomechanics that are needed.”

A 3D printed vertebra. Image: Ralph Mobbs

The team took a model of the metastasis and made another model for the operation. They used porous titanium for the reconstruction implant and employed CAD in part to create the final product. “Titanium can be a great material because it has mechanical properties that, if used in the right way, can provide structural support,” he says. “It also allows you to be extremely fine in detail.”

Despite his enthusiasm for the technology involved, the pressure was increased by the fact that he couldn’t simply take part of the tumor out and then come back for the rest another time, he says. But he had to do what he could and perform the surgery. “I’m happy to say the process of implanting went well. The hole was the same as had been preplanned and it went perfectly, like a key into a lock,” he says.

There weren’t any complications from the implant, materials, or mechanics, he adds. “But there were in terms of speech because we had to go through the mouth,” he says. “But the tumor, thankfully, was removed.”

With 3D printing having encouraging results, Mobbs says a new challenge may be patient expectations and wanting a perfect image of how things were before surgery, something that isn’t always possible.

Still, he looks forward to the time when his profession can perfect the technology and says his team has more options open to them in Australia, where they don’t have the same regulatory constraints as other parts of the world. “It’s gratifying to see this implantation through 3D printing be a possible choice,” he says. “Defining a problem and finding the solution, that’s what it’s all about for so many in my field. This is the future, and patients can find improved lives from it.”

Eric Butterman is an independent technical writer.