When a 35-year old patient was admitted to the Tokuda Hospital for tonsillitis treatment, he and his doctors were surprised to discover the man also had a neoplasm in the rib. A neoplasm is an abnormal mass of tissue, or tumour, in the body. In this case, the neoplasm was benign but nether-the-less it was determined it needed removing to prevent future medical problems, such as difficulty breathing and general discomfort.
The neoplasm was discovered during X-rays of the chest area. The treatment for a neoplasm in the rib is to remove the bone and replace it with an implant to rebuild the chest. Implants have to be a perfect physical replacement of the original rib. These are usually manufactured in titanium. However, the cost to manufacture titanium implants is extremely high. In this case, the rib had to be a perfect representation of the original rib shape, both in terms of its thickness and curvature, and 3D printing was chosen to achieve this.
On the right side – the patient, Ivaylo Josifov, on the left side – the cardiac surgeon.
3D printing a rib
Work on the 3D printed rib started in Bulgaria. The bone was digitally scanned at the hospital to create a 3D visualisation of it. This scan was then sent onto the design team. The 3D scan was sliced so as to be compatible with the 3DGence 3D printer. The file was then prepared for 3D printing and reviewed by medical experts to ensure it was up to specification. The rib was then printed using a Food and Drug Administration (FDA) certified polyamide. The FDA has certified a number of 3D printable materials as suitable for human application. The polyamide in this case is unspecified.
“Our 3D printers ensure high 3D dimensional accuracy which was crucial in this particular medical procedure.” says Filip Turzyński, Quality Development Manager at 3DGence. “Individually designed rib model allowed for a very accurate implementation of the new element in place of the removed bone. Replacing the missing rib with a 3D printed segment with the same shape, curve, width, and thickness was possible with the use of 3DGence 3D printer.”
Before implantation, the rib implant was drilled and prepared. 3 mm holes were drilled into the new implant to facilitate broaching and tissue proliferation. The model was then sterilised in stages. First using ethylene oxide, then gamma radiation, then in an autoclave at 140 °C. Once this process was completed, the implant was ready for implantation. It was delivered to surgeons and the patient was put under anaesthesia so the surgery could begin.
The surgery went smoothly and the patient, now a few months on since, is in good health. The 3D printed rib has taken to his body perfectly and his doctors are happy with the progress he is making. They hope it will pave the way for more surgeries like it from other medical teams in the future. The doctors are also already planning new projects using implants printed in 3D technology in their own hospital, such as an implant of 3 ribs with a sternum, which is obviously a more complex project than printing one rib.
“This is a new era in thoracic wall reconstruction for patients with tumours that require bone-cartilage structures to be removed.” said Prof. Minchev, Head of the Cardiothoracic Surgery Department at Tokuda Hospital, “The material used has proven tissue compatibility and the accuracy of reproduction allows for large chest wall resections and their single substitution with individually designed implants.”
3D printing is already being used in a wide range of medical applications, from making bionic hands to artificial hearts. The most obvious application is 3D printing low-cost prosthetics. We can also 3D print extremely accurate medical models and structures, as well as medical equipment and tools. Although the technology hasn’t revolutionised medicine yet, slowly but surely it is being introduced across the medical field.
3D Printer: 3DGence F340.
Material: Unspecified FDA certified polyamide.
This information and all embedded photos were first published on the 3DGence website. If you liked this case study, you can find more like it at our medical page. We recommend reading this one next, which covers the story of a man receiving a 3D printed jaw.