Could 3D-Printed ‘Bone Bricks’ End Amputation?
Sana Kazilbash posted on June 30, 2020 |
Bomb injuries lead to bone-mending discovery.

These ‘bone bricks’ are pieced together to fill the gap caused by missing bone. (Image courtesy of The Conversation.)
These ‘bone bricks’ are pieced together to fill the gap caused by missing bone. (Image courtesy of The Conversation.)

Researchers at the University of Manchester have developed 3D-printed ‘bone bricks’ as a cost-effective method of repairing shattered limbs that are a result of blast explosions. These bone bricks are designed to click together like Lego bricks, creating a personalized fit for blast victims at a time of critical need at Syrian refugee camps.

Thousands of bomb blast survivors suffer jagged bone breaks which are almost impossible to fix. Lacking access to sophisticated orthopedic surgery at fully equipped hospitals, refugees are limited to infection-ridden camps with often untrained medics, making amputation the most likely outcome. Experts estimate that 100,000 Syrians have been affected by significant bone loss to date, resulting in over 30,000 amputations. Prosthetics are not available or suitable for every amputee.

Current bone repair techniques have their limitations. One method involves the harnessing of the limb in an external fixation device (a fixator) or frame (Ilizarov apparatus), enabling the bone tissue to slowly reconnect. This procedure is time-consuming, medically complicated, and not always effective. Problems often arise from metal piercing through skin and soft tissue to connect the fixator or cage to the bone. Another process involves the placement of a pin or plate implant to stabilize the bone gap and allow the tissue to regenerate.

With complex orthopedic surgery unavailable at refugee camps, a surgeon may suggest bone grafting, which involves using transplanted bone to rebuild shattered bones. However, the constant risk of infection at refugee camps makes successful bone grafts improbable.

This is where the newly conceived 3D-printed bone bricks come in. The treatment uses medical scaffolds made of polymer and ceramic materials, which can be clicked together to create a temporary structure that perfectly fills the bone gap caused by the blast injury. These bone bricks would have all the support of a normal bone in compression, while inducing the formation of new bone tissue around the structure. As the bone regenerates, the bricks dissolve. Each of these degradable bricks has pores containing antibiotic ceramic paste, which combats infection in a remarkably practical way during the healing period.

Dissolvable scaffolds enable bone tissue regeneration to mend fractures. (Image courtesy of The Conversation.)
Dissolvable scaffolds enable bone tissue regeneration to mend fractures. (Image courtesy of The Conversation.)

This limb-salvaging solution uses low-cost 3D-printing technology and can be executed in a relatively straightforward manner. All a clinician has to do is piece together a collection of ready-made bricks to create a custom-fit structure for a particular defect. The treatment is expected to cost less than USD$245 (GBP£200) for a typical 100mm fracture injury, as opposed to other methods which can cost anywhere from $330 to $1,230 (£270 to £1,000).

The bone brick project is led by Paulo Bartolo, Chair Professor of Advanced Manufacturing at the University of Manchester. Bartolo’s academic interests include biofabrication for tissue engineering, which involves constructing bone, nerve, cartilage and skin through the use of 3D printing. With Glen Cooper and Andrew Weightman as his Manchester research partners, Bartolo is collaborating with Bahattin Koc from Sabanci University in Turkey and Gordon Blunn from the University of Portsmouth. Clinical support is being provided by Amer Shoaib, a consultant orthopaedic surgeon with humanitarian experience on the frontlines of various crisis zones. The research is being funded by the Engineering and Physical Sciences Research Council, as well as the Global Challenges Research Fund which supports researchers in their quest to address challenges faced by developing countries.

Andrew Weightman (left) and Paulo Bartolo (right). (Image courtesy of The Conversation.)
Andrew Weightman (left) and Paulo Bartolo (right). (Image courtesy of The Conversation.)

The team is approaching the final stages of the project.

“We have already evaluated the modular bone bricks system in a computer simulation, created prototypes of the modular bone bricks using 3D printing technologies in the lab, and conducted in-vitro (laboratory) testing of mechanical and biological characterization of the bricks,” explains Bartolo. “We’re now in the process of integrating with the software that will link the scanning of information from the wound area with the identification of the correct type of bone bricks and assembly mechanism.”

The next steps will involve in-vivo (in a living thing) animal testing, after which the project will undergo clinical trials on human patients with significant bone loss.

Apart from advancing emergency healthcare in the developing world, the research team hopes that the proposed bone brick technique will lead to an improved patient experience in situations involving accidents and natural disasters—finally giving victims a personalized alternative to limb amputation.

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