A world-first clinical trial in Japan could begin as early as July 2026 to test a 3D-printed regenerative tissue implant designed to repair knee bone and cartilage. The implant could allow some patients to potentially delay or even avoid total knee replacement.

Led by Keio University, Fujita Health University, and startup Cyfuse Biomedical, the treatment uses a patient’s own fat cells to create a 3D-printed implant that can be placed into damaged areas of the knee.

The goal is to provide a long-term, restorative alternative to traditional metal knee implants. About 790,000 to 800,000 total knee replacements are performed each year in the United States, according to the American College of Rheumatology.

The trial will focus on patients with idiopathic osteonecrosis of the knee, a condition that leads to bone loss. According to Nikkei Asia’s Health Care, patients at the participating universities will receive an 8-millimeter cylindrical implant placed directly into damaged knee tissue.

The implant, made from the patient’s own cells, is designed to release nutrients that support the regeneration of bone and cartilage, researchers say.

The technology has already been successfully tested in animals, including pigs, and is now advancing to human trials. If successful, it could offer a new option for millions suffering from knee osteoarthritis.

Cyfuse’s 3D-printing approach uses cells without artificial additives, reducing the risk of rejection. The company has also used similar technology with umbilical cord cells to help regenerate peripheral nerves in patients with finger injuries.

Masahiro Sanjo, Cyfuse’s chief financial officer, said the goal is to “create a business around our unique regenerative medicine products and contribute to the expansion of this growing market.”