Manufacturing of Biodegradable Intramedullary Nail With High Strength

Abstract

Intramedullary nails (INs) have significant advantages in rigid fracture fixation. Conventional metal INs for long bone fracture fixation often lead to delay union or even nonunion healing due to their stress shielding effect and lack of biological activity. Besides, undegradable metals require a second surgery to remove them, which will not only impose a potential risk to the patient but also cause additional costs. Manufacturing high-strength biodegradable INs (BINs) is still a challenge. Here, an entirely new type of high-strength bioactive magnesium-containing silicate (CSi-Mg) BIN is manufactured by using casting, freeze drying and sintering technique. It has extremely high bending strength (> 41 MPa) and stable internal and external structure. We have systematically studied the influence of parameters such as the paste component, freeze drying process, and sintering process on the mechanical strength involved in the manufacturing process. According to our manufacturing method, a wide range of inorganic ceramic implants and BINs with different sizes can also be fabricated. The CSi-Mg BIN also has good bioactivity and biodegradation property. This bioceramic BIN and manufacturing process are expected to be applied to a variety of orthopedic medical devices. This novel bioactive BIN is expected to replace the traditional metal IN and become a more effective way of treating fracture.