In the field of orthopaedics and traumatology, Mg-based implants have attracted significant attention as promising biomaterial due to their biocompatibility, biodegradability, and suitable mechanical properties. However, high corrosion rate and excessive hydrogen gas formation of pure Mg implants are still major concerns in the clinical applications. Therefore, it is important to understand the degradation behaviour of Mg-based implants and their effect on bone remodelling. In this study, we investigated i) the degradation behaviour of ZX00 (Mg<0.5wt%Zn<0.5wt%Ca) and extra high-purity Mg (XHP-Mg) implants, ii) their safety and effects on bone in-growth in Sprague Dawley rats and compared to state-of-the-art titanium implants. Our findings suggest that both Mg alloys support bone formation and remodelling but ZX00 is more favourable due to the monotonous degradation performance.