Precision 3D printed implants in the scan-to-surgery process can halve recovery time for patients
In 2019, it has been estimated that 600,000 implants were produced with 3D printing. Demand-driven by an ageing population, joints wearing out with sports, bone loss with trauma, and medical conditions, it is no wonder the requirement for implants is projected to grow to four million by 2027.
Additive manufacturing has been used since the 1990s to customise patient-specific implants. This technique makes surgeries easier with 3D printed surgical guides and also leads to better healing outcomes for the patient. Osseointegration is the medical term for the direct structural and functional connection between living bone and the surface of a load-bearing implant.
Because titanium alloy is around three to four times stiffer than bones, biomechanical engineers must tailor the size and shape of the implant’s lattice structure to adjust the pliability of the implant to be closer to the bone’s stiffness. Research has shown the rough texture of lattice structures in implants (that can only be made with 3D printing) promotes osseointegration and facilitates soft tissue and bone regrowth. Metal implants are 3D printed using powder bed fusion technology, including direct metal laser melting, with titanium, cobalt-chromium alloys, and stainless steel being the most suitable materials due to their excellent corrosion resistance, mechanical strength, and no cytotoxicity properties.
With advancements in technology that uses artificial intelligence to segment a patient’s radiological scan to create the computer-aided design as the precise input for the 3D printing process, surgeons are equipped with 3D visualisation tools for explaining the surgical procedures to patients, enabling more informed decision-making and peace of mind. AI-powered technology can also segment the spinal vertebrae within minutes with an accuracy rate of 95% to design custom implants. Previous segmentation methods required thousands of hours of manual identification and markups to hundreds of computerised tomography (CT) scans.
The final approved design is sent through to Additive Engineering for manufacturing. The file is checked to be suitable for 3D printing. The as-printed part is heat- treated, surface roughness and measurements checked, sterilised and sealed in tamper-resistant packaging, and sent to the surgeon within days for use in surgery.