Soon, we’ll be able to 3D-print parts for knee surgery

20 Apr 2017

Knee injury. Image: Elena Kharichkina/Shutterstock

Knee surgery could be set for an overhaul as researchers have developed cartilage-mimicking, 3D-printing material in the US.

When it comes to the future of knee surgery, it appears that, one way or another, 3D printing will play a part.

A cartilage-mimicking material created by researchers at Duke University is paving the way for custom-built, replacement knee parts.


The hydrogel-based material, according to the researchers, is the first to match human cartilage in strength and elasticity, while also remaining 3D-printable and stable inside the body.

Human knees come with a pair of built-in shock absorbers called the menisci. This cartilage cushions our knees, but wear and tear can be telling.

A key concern is how little the menisci heal after humans reach adulthood, meaning synthetic substitutes are often needed.

“We’ve made it very easy now for anyone to print something that is pretty close in its mechanical properties to cartilage, in a relatively simple and inexpensive process,” said Benjamin Wiley, author of the paper.

The cartilage-mimicking material created by researchers at Duke University. Image: Feichen Yang

The cartilage-mimicking material created by researchers at Duke University. Image: Feichen Yang

Mix and match

Wiley and his team did this by taking hydrogels, long considered as possible cartilage replacements, and mixing them together – traditionally, hydrogels are either too strong or not stretchy enough, depending on the choice.

The team created a double network hydrogel by mixing one overly rigid one with a particularly stretchy variant, adding nanoparticle clay to make it 3D printable.

“This is really a young field, just starting out,” Wiley said.

“I hope that demonstrating the ease with which this can be done will help get a lot of other people interested in making more realistic printable hydrogels with mechanical properties that are even closer to human tissue.”

Pen and paper

Wiley’s approach isn’t the only novel idea when it comes to future knee surgery. It’s not even the only 3D-printing idea.

The incredible ‘Biopen’, for example, can help surgeons ‘draw’ cells onto injured body parts, with knees the first port of call.

First, a doctor extracts some cells from an upcoming patient – in this case, someone suffering from a knee cartilage injury. Then the team duplicates these cells over and over until they have enough to work with.

These incredibly fragile cells are then loaded into the Biopen, allowing the surgeon to ‘draw’ the cells, layer after layer, onto the knee.

The cells react to where they are, adapting and transforming to create the desired outcome.

Gordon Hunt was a journalist with Silicon Republic