A comprehensive review on biocompatible Mg-based alloys as temporary orthopaedic implants: Current status, challenges, and future prospects

Mg and its alloys are drawing huge attention since the last two decades as a viable option for temporary implants applications. A commendable progress has already been made in the development of these alloys. The biodegradable nature of Mg, appreciable biocompatibility of elemental Mg, and its close resemblance to natural bone in terms of density and elastic modulus make them highly preferable option amongst other available alternatives in this field. This review article presents an overview covering the recent advancements made in the field of Mg-based biodegradable implants for orthopaedic implant applications. The paper focuses on alloy development and fabrication techniques, the state of the art of important Mg-based alloy systems in terms of their mechanical properties, in-vitro and in-vivo degradation behaviour and cytotoxicity. Further, the paper reviews the current progress achieved in the clinical transition of Mg-based alloys for orthopaedic fixtures. The review also includes the degradation mechanisms of the alloys in physiological environment and highlights the mismatch existing between the rate of bone healing and alloy degradation due to rapid corrosion of the alloys in such environment, which has still restricted their widespread application. Finally, the surface coating techniques available for the alloys as an effective way to reduce the degradation rate are reviewed, followed by a discussion on the future research prospects. (C) 2021 Chongqing University. Publishing services provided by Elsevier B.V. on behalf of KeAi Communications Co. Ltd.

Automated summary

Magnesium and its alloys have gained significant attention as a viable option for temporary implants in the past two decades. Their biodegradable nature, excellent biocompatibility, and similarities to natural bone make them highly desirable in orthopedic implant applications. This review article provides an overview of recent advancements in the field of magnesium-based biodegradable implants, including alloy development, fabrication techniques, mechanical properties, degradation behavior, and clinical application progress. The article also discusses the degradation mechanisms and challenges in physiological environments, as well as surface coating techniques to reduce degradation rates.