Plates made from magnesium alloy with a long period stacking ordered structure promote bone formation in a rabbit fracture model

Operative treatment is an option for fractures when the fracture is unstable or the patient wishes to return early to daily life or social activities. Metal plates such as titanium and stainless steel are often used in fracture surgery, but the metal plate lacks bone-healing activity and is not bioabsorbable, requiring a second surgery to remove it after bone union. Here we show that a magnesium (Mg) plate made from an alloy of yttrium, zinc, and aluminum with magnesium as the main component in a long-period stacking ordered structure promotes bone formation in a rabbit tibia fracture model and is also bioabsorbable. We show that the Mg plate significantly promoted bone and callus formation compared to a titanium plate in the rabbit tibia fracture model. Moreover, the Mg plate was mostly bioabsorbed once bone union was achieved, but rabbits showed no evidence of biotoxic effects, such as weight loss or increased blood magnesium levels. We also demonstrate that treatment with exogenous magnesium significantly enhanced calcium deposition in an in vitro osteoblast culture system. Magnesium is an essential element, and its radiolucency facilitates observation of the fracture site during Mg plate fixation, while its lack of magnetic properties allows its use in patients who require MRI scans. Accordingly, we propose that a use of a Mg plate could be beneficial in treating bone fracture.