A hospital in China known as First Hospital has completed what is believed to be the first knee replacement surgery using a 3D printed implant made of tantalum, a metal commonly alloyed with titanium.
“Tantalum is a rare, blue-gray metal, with an extremely high melting point of over 3,000 degrees Celsius. Researchers have mixed it with titanium alloys to improve the stress absorption of 3D printed implants. Because the melting point of tantalum metal is too high to produce using most 3D printers on the market, 3D printed metal implants are more likely to be made using a metal like titanium.”
According to their proponents, custom 3D printed tantalum implants offer some unique positive characteristics. “They are more compact, which can help make the implants more stable, thus reducing the risk of surgical complication and time in the operating room, as well as making the surgery itself simpler,” they state.
According to CQNEWS.net, a website based out of the Chinese municipality of Chongqing, the percentage of osteoarthritis of the knee is increasing among the country’s adults, particularly in ages 50 to 59. First Hospital in Chongqing performs roughly 400 knee replacement surgeries each year.
“We’ve seen 3D printed implants for knee replacement surgeries fabricated out of metals such as cobalt-chromium and nylon titanium, while porous tantalum is more often used to 3D print patient-specific implants for spinal implants and hip replacements” wrote Sarah Saunders for 3Dprint.com.
Yang Liu, M.D., head of the surgical department at First Hospital, explained, “Total knee replacement is the most effective way to treat late-stage knee diseases, as it can reduce the pain for patients and improve their quality of life.” Professor Liu, who works on an implantation research project with the National Key Research and Development Program of China, also collaborates with several domestic companies to 3D print porous tantalum joints. Professor Liu used CAD, 3D printing technology, and tantalum metal to make the implant itself, while tantalum pads were used to fill the patient’s large bone defects. The implant is said to be the world’s first 3D printed tantalum knee joint.
