Renishaw Case Study: Benefits of Smart Implants with Sensor and 3D Printing Technologies

One of the many reasons I am grateful to be living in the current century is a much higher quality of healthcare. In times past, blacksmiths and barbers were also medical care providers, along with healers and specialized bone setters. These archaic provider options don’t sound particularly fun to me, but thankfully, medical treatment has advanced a great deal over the years.

Research institutes and companies are constantly working to improve healthcare technology – surgeons have been using metal implants since the early 1900s for diseases like inflammatory rheumatoid arthritis and osteoarthritis, and patients can now receive 3D printed metal implants that have been made just for them.

Global metrology company Renishaw has worked on many innovative 3D printing medical projects for patients of all types, and Matt Parkes, a Senior Medical Development Engineer at Renishaw, is currently working on another one. In a recent case study, the company shares that Parkes is collaborating with Western University in Ontario to discuss how smart implants are improving the ways in which we treat bone injuries and diseases.

Traditionally manufactured implants have long caused difficulties for surgeons and patients. They can only be made in a certain number of shapes and sizes, so patients likely won’t get one with an accurate fit, and metal implants can remove stress from a patient’s bone, called stress shielding, which weakens the bone. Additionally, traditional implants, especially for those in joint replacement procedures, can loosen, sometimes as a result of poor osseointegration.

This is why researchers are working to further develop smart implants, which, first and foremost, give patients a better fit. By developing smart implants, healthcare providers can improve patient outcomes significantly. Patients equipped with smart implants, rather than conventionally manufactured ones, have a lower risk of getting a serious infection post-op, will suffer from less discomfort and pain, and could also be less likely to need revision surgeries in the future.

Two options make implants smart – either using 3D printing technology to make patient-specific implants (PSIs) from CT data, or incorporating sensors that can collect patient-specific data.

PSIs that are developed using a patient’s CT scan will encourage the implant to more fully integrate with the bone, which lowers the risk of loosening, pain, or further surgical intervention. Thanks to the inherent additive nature of 3D printing, which builds materials up rather than cutting materials away, surgeons can create PSIs that more accurately fit their patients, and the technology, as we know, is capable of creating far more complex geometries.

3D printing also makes it possible for surgeons to control different material properties, so they can manufacture implants that mimic a patient’s bone density, stiffness, and trabecular structure, which, as the case study notes, “can reduce stress shielding and improve osseointegration and physical function further.”

As previously mentioned, implants can also be made smarter with the addition of sensors, which give doctors a more accurate way to measure patient data like temperature. Advanced sensor technology could even make it possible one day to develop implants that can detect infection and automatically secrete a dose of antibiotic before it becomes an issue, which would keep patients out of the hospital.

In one example, sensors can be incorporated into bone reinforcement implants, which help fractures heal. The sensors could measure how much strain is being exerted on the implant, which shows how much the fracture has healed and gives surgeons a better idea of when to move the patient to the next stage in healing therapy.

By adding accelerometers to implants, healthcare professionals can monitor a patient’s movements and collect data remotely, which allows them to see if a patient is keeping up with their prescribed physiotherapy; non-compliance with this, and not resting enough, can also lead to implants becoming loose.

Renishaw and Western University previously set up the Additive Design in Surgical Solutions (ADEISS) Centre on the university’s campus, which brings together academics and clinicians to work on developing novel 3D printed medical devices. The institute is currently developing technology in the sensor implant field, and recently introduced its smart hip concept, which uses accelerometers and temperature sensors to collect patient data, which is later communicated to a remote device.

There are still some challenges to get past before smart implants can be adopted around the world – clinical studies need to be conducted in order to collect performance and safety data on the implants, which has to be done in line with certain regulations, depending on the country. Additionally, personal data in smart implants needs to be processed. But if we can get to widespread clinical adoption of implants with 3D printing and sensor technologies, they could benefit surgeons and patients in a myriad of ways.

You can read the full Renishaw case study here.

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[Images: Renishaw]