Fit to print

RMIT University in Melbourne, Australia, is championing a groundbreaking new research project to treat tumours and bone cancer using custom-made, 3D printed implants. The five-year project – Just in Time Implants – will combine 3D printing, robotic-assisted surgery and advanced manufacturing to create tailored implants on demand for patients undergoing surgery to removed diseased bone.

The use of 3D printing in the medical arena is still in its infancy, although its application is steadily increasing from the dental implants, and hip and shoulder inserts currently used, to more complex applications, such as the spinal support recently approved by US FDA.

The Just in Time Implants project aims to revolutionise how patients are treated surgically by bringing such technology closer to – if not into – the theatre.

While patients are having their cancers removed in the operating theatre, a bespoke implant that will exactly fill the space left after the removal of diseased bone is being custom printed in the next room. The project will increase the number of surgical options available to both patients and surgeons, increasing the potential for limb-saving surgery and improving patient and healthcare results considerably.

Traditionally, implants used in surgeries are standardised in terms of their shape and size, or can take weeks to deliver if a patient is lucky enough to be receiving a customisable implant. Neither option is particularly attractive for patients or their surgeons, however – it’s not ideal to have to wait weeks for a bespoke implant or to settle for an ill-fitting, potentially uncomfortable standardised one. Even if the patient is to receive an implant specifically made for them, the process is highly manual and time-consuming. Another drawback is that it doesn’t allow anatomical changes that occur on the day, meaning a custom implant could become redundant and unusable with even the slightest body alteration.

Tailored care

In recent years, 3D printing – also known as additive manufacturing – has revolutionised the way in which doctors and medical professionals can care for their patients. The technology enables implants to be modelled on a patient’s specific CT scan or MRI and printed using medical-grade materials – such as titanium or certain polymers – much more quickly than conventional manufacture allows.

RMIT University – known as the Royal Melbourne Institute of Technology until 1992 – has joined forces with a long-term collaborator, the US-based medical technology company Stryker, and other Australian institutions and organisations, in an innovative research project aimed at exploiting the advantages of 3D printing, including its precise nature and quick turnaround time.

“RMIT is leading research in a major new project that is set to transform the way physicians surgically treat bone cancer and other tumours, and dramatically improve patient and healthcare outcomes,” explains Professor Milan Brandt, the university’s technical director advanced manufacturing precinct and director for additive manufacturing.

“The five-year project brings together the Australian Government, RMIT, the University of Technology Sydney (UTS), St Vincent’s Hospital Melbourne and Stryker.

“Worth more than A$12.1 million in research effort, the work is funded by Stryker with co-funding from the Innovative Manufacturing Cooperative Research Centre. The project brings together expertise from 3D printing and robotic surgery to create tailored implants for patients requiring tumourremoval surgery,” continues Brandt, whose expertise lies in manufacturing, materials and mechatronics, specifically in the processing of titanium.

“The aim is to bring this technology to the theatre through custom-printing an implant to precisely fill the space left after removal of the diseased bone while the patients are in the operating theatre. This process will expand the surgical options available to patients and surgeons and increase the potential for limb-saving surgery. The approach represents a major shift in the way implants are designed, manufactured and supplied, and could lead to bespoke local manufacturing.” The implants would be made from titanium alloy and printed using either selective laser or electron beam melting technology, states Brandt. This involves a layer of metal powder pre-placed on a metal platform being irradiated by a laser or electron beam based on the CAD design of the implant. The laser or electron beam melts the powder based on the implant design and fuses it to the layer below, forming a solid metallurgical bond.

This method means the implants will be customisable and feature multidensity cross-sections and surfaces. The hope is that such inserts will allow patients to retain more of their own bone structures and soft tissues, and reduce the time they have to spend in hospital.

New dimension

As 3D printing, particularly for use in implants, is still an emerging field, regulations and standards are still under discussion globally. It was only in December 2017 that the US FDA issued guidance for industry and staff regarding additive manufactured medical devices after noting rapid technological advances and increased availability of additive manufacture fabrication equipment had led to more investment and expanded use by the medical device industry.

Other discussions are currently under way regarding how 3D medical devices are classified – each device is placed in one of three classes, depending on the level of risk they pose a patient – and redefining the term ‘custom-made’ when it comes to such devices. While custom-made implants are historically low risk and few in number, the increasing complexity and volume of such items and devices means that a rethink is necessary to ensure they are subject to the same high-level scrutiny as mass-produced devices.

Brandt is optimistic about the Just in Time Implant project. “In the case of [a] one-off bone specific and patient-specific implant, the regulation allows the surgeon to implant such an implant with patient’s consent,”he explains, suggesting that there are no current regulations regarding their use.

“Such an implant, however, is not covered by any health fund, so the patient has to bear the cost. In future, 3D-printed implants will be covered by medical insurance.” It is hoped that the Just in Time Implants projects will also help to train medical engineers in additive manufacturing – a term used to describe the technologies that build 3D objects by adding layer upon layer of material, whether that be plastic, metal, concrete or – maybe one day – human tissue. This will not only make the technology more accessible in Australia, but means it is more exploitable and thus can be opened up to a wider platform, perhaps even worldwide.

Stryker – which is based in Michigan in the US, with offices around the world – and RMIT have a long-standing relationship, says Brandt. The Just in Time Implants project builds on this affiliation through the combination of RMIT patent-pending technology on implant design and Stryker’s in-depth robotic and image processing technology.

The project shows just how forward-thinking Australia’s medtech environment is, offering research partners a unique opportunity for revolutionary research projects.

Global benefit

“The benefits to each party are significant,” notes Brandt. “Stryker sees Australia as leading the way globally in developing and implementing new manufacturing models and technology in the medical space, through the combination of robotic surgery and additive manufacturing. This has the potential to deliver significant benefits to patients in Australia and across the world. The benefit to RMIT includes working with a major global supplier of medical implants capable of commercialising project intellectual property. Also, there is potential to employ project-funded researchers [after the] project and opportunity for further projects in biomedical space.”

The project will provide the foundations for advanced manufacturing capabilities that will guarantee a competitive advantage not only in Australia, but around the world. Indeed, once the project is complete, the process could be outsourced and rolled out worldwide. “One of the project partners, UTS, is examining the economics and business options for the commercialisation of the technology as the project progresses,” explains Brandt. “The project could be rolled out worldwide and this will form part of the commercialisation strategy.”

UTS believes that the project will provide direct business opportunities for Australian companies to become medical suppliers, and for the technology and manufacturing knowledge to be transferred to other local industries over time.

This project could present a major shift in the way implants are designed, manufactured and supplied, leading to a service to supply bone cancer patients with locally produced bespoke implants. It is an example of how research-led innovation in manufacturing could make a real difference to patients, offering more surgical options, better implants and processes.