Harald Kissel, R&D manager at Sandvik Additive Manufacturing, shares insight into how titanium powder and AM are revolutionising medical implant production.
In 1891, Professor Themistocles Glück performed the first hip replacement using a ball and socket made from ivory. Medical implant technology has since progressed, and recent developments in additive manufacturing (AM) and materials technology have even made bespoke 3D printed implants possible.
The adult human body has 206 bones, which all have an important function of providing structural support and protecting our vital organs. Because of the important jobs bones are tasked with, a damaged bone can have severe consequences to a patient’s health and quality of life.
If a bone has been severely damaged to the point where it cannot heal and function correctly, a medical implant must be inserted. This is particularly true for serious accidents that destroy areas that are complex to treat, such as the skull or spine.
Typically, creating an implant that suits the patient’s needs requires multiple medical appointments. At a time when a damaged bone could be causing the patient pain, reduce their mobility and affect their lifestyle, this long wait for an implant can be incredibly uncomfortable.
Despite the wait seeming long to the patient, the design process has actually been sped up to relieve them more quickly ― but this does result in a sub-optimal implant that isn’t tailored to their bodies. For skull injuries, this could even mean the patient is fitted with a mesh implant, which can be weak and lack precision.
Fortunately, AM and titanium powder have now allowed the production of made to measure medical implants that are biocompatible and fit to the body seamlessly. The advancement of 3D printing has even made it possible to fabricate carbon copies using anatomical data of our own skulls.
Titanium has excellent properties as it can resist corrosion while simultaneously demonstrating strength, low weight and biocompatibility. AM using titanium powder allows complex bespoke implant designs to be produced at speed, in shapes no other manufacturing technology can deliver.
The precise placement of the metal powder allows the production of a lightweight structure that reduces material waste. AM is seen as a disruptive technology in the medical sector, providing life-changing solutions to patients.
The custom designs are made using a computerised tomography (CT) scan, an imaging technique that uses x-ray measurements taken from many different angles to produce a tomographic image of the body. The technique is hailed as a way to see inside the body without surgery and goes beyond any other medical implant design method.
Sandvik manufactures its own Osprey titanium powders in its powder plant, located in Sandviken, Sweden, which was awarded the ISO 13485:2016 medical certification in the summer of 2020. The powders are now approved for use in the additive manufacturing of medical applications.
The fully automated production process at Sandvik’s plant ensures reliable titanium powder quality. In-house metallurgical capabilities allow Sandvik to conduct alloy development, alloy research and tuning of materials to the intended application.
Sandvik is taking part in an innovative research projects in the medical 3D printing sector with The Swiss M4M Center in Switzerland, a public private partnership initiated by the Swiss government. The project aims to build up and certify a complete end-to-end production line for medical applications such as implants.
This will progress medical 3D printing to a point where bespoke implants at the forefront of technology can be designed and manufactured quickly and cost-effectively. Sandvik is contributing its material expertise to facilitate the initiative. The joint venture aims to revolutionise medical devices and benefit the lives of thousands of people.
While ivory is no longer used as a medical implant material, the options available to patients have since remained limited until now. Fortunately, 3D printed implants are becoming a viable option for patients with life-changing injuries. Developments in titanium powder and AM have brought bespoke implants into reality, giving patients with damaged bones exceptional implant designs at speed.