In the first surgery of its kind worldwide, an 84-year-old Chinese man has received knee surgery using 3D printing technology to fill large bone defects with tantalum, a rare metal, at a hospital in Chongqing Municipality, reported cqnews.net.

As the incidence of arthritis among people aged from 50 to 59 has reached 62 percent, the first hospital affiliated to AMU (southwest hospital) now performs about 400 knee replacement surgeries annually, according to reports.

"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," said Yang Liu, a professor at the hospital.

However, bone defects may occur around the joint due to post-operative infections or other reasons. The shape of the bone defects varies greatly, and existing modular metal cannot correct the defects.

Tantalum is used in dental and surgical implants; however, titanium alloy is more commonly used as the high melting point of tantalum exceeds the limit of most 3D printers available.

Porous tantalum has been developed to solve the technical problem. Tantalum pads are individually designed for patients by computer-aided design and precise 3D-printing technology.

The surgery is greatly simplified, avoiding many possible risks. Mr. Zhang, who received the knee surgery was able to complete some basic movements on the first day after his surgery and is expected to leave the hospital in just four to five days.