Biodegradable Magnesium (Mg) Implantation Does Not Impose Related Metabolic Disorders in Rats with Chronic Renal Failure

Implantable Dental Barrier Membranes as Regenerative Medicine in Dentistry: A Comprehensive Review

BACKGROUND

Periodontitis and bone loss in the maxillofacial and dental areas pose considerable challenges for both functional and aesthetic outcomes. To date, implantable dental barrier membranes, designed to prevent epithelial migration into defects and create a favorable environment for targeted cells, have garnered significant interest from researchers. Consequently, a variety of materials and fabrication methods have been explored in extensive research on regenerative dental barrier membranes.

METHODS

This review focuses on dental barrier membranes, summarizing the various biomaterials used in membrane manufacturing, fabrication methods, and state-of-the-art applications for dental tissue regeneration. Based on a discussion of the pros and cons of current membrane strategies, future research directions for improved membrane designs are proposed.

RESULTS AND CONCLUSION

To endow dental membranes with various biological properties that accommodate different clinical situations, numerous biomaterials and manufacturing methods have been proposed. These approaches provide theoretical support and hold promise for advancements in dental tissue regeneration.

The Recent Developments of Thermomechanical Processing for Biomedical Mg Alloys and Their Clinical Applications

Magnesium (Mg) alloys have gained much attention for biomedical applications, due to their attractive properties, such as high specific strength, low density, low elasticity modulus, high damping capacity, biodegradation, and relatively good cytocompatibility. However, the biomedical use of Mg alloys also faces several challenges, primarily due to their low corrosion resistance and insufficient strength. Therefore, improving the strength and corrosion resistance of biomedical Mg alloys has become a critical issue. This review briefly summarizes the selection of appropriate alloying elements for biomedical Mg alloys, which is the fundamental factor in determining their microstructure, cytocompatibility, mechanical properties, and corrosion performance. It also discusses typical thermomechanical processing methods, including hot extrusion, hot rolling and hot forging, and examines the influence of deformation mode on microstructure, mechanical properties, and degradation behavior. Specifically, combining different thermomechanical processing methods could be an optimal choice, as it leverages the high efficiency and effectiveness of each method. Finally, the clinical application of biomedical Mg alloys in various fields are summarized and discussed to highlight their potential prospect and corresponding challenges. This review aims to provide insights for the rationale design and development of high-performance biomedical Mg alloys for widespread clinical applications.

Chronic kidney disease: a contraindication for using biodegradable magnesium or its alloys as potential orthopedic implants?

Magnesium (Mg) has gained widespread recognition as a potential revolutionary orthopedic biomaterial. However, whether the biodegradation of the Mg-based orthopedic implants would pose a risk to patients with chronic kidney disease (CKD) remains undetermined as the kidney is a key organ regulating mineral homeostasis. A rat CKD model was established by a 5/6 subtotal nephrectomy approach, followed by intramedullary implantation of three types of pins: stainless steel, high pure Mg with high corrosion resistance, and the Mg-Sr-Zn alloy with a fast degradation rate. The long-term biosafety of the biodegradable Mg or its alloys as orthopedic implants were systematically evaluated. During an experimental period of 12 weeks, the implantation did not result in a substantial rise of Mg ion concentration in serum or major organs such as hearts, livers, spleens, lungs, or kidneys. No pathological changes were observed in organs using various histological techniques. No significantly increased iNOS-positive cells or apoptotic cells in these organs were identified. The biodegradable Mg or its alloys as orthopedic implants did not pose an extra health risk to CKD rats at long-term follow-up, suggesting that these biodegradable orthopedic devices might be suitable for most target populations, including patients with CKD.

Magnesium implantation as a continuous hydrogen production generator for the treatment of myocardial infarction in rats

Molecular hydrogen is an emerging broad-spectrum antioxidant molecule that can be used to treat myocardial infarction (MI). However, with hydrogen inhalation, the concentration that can be reached within target organs is low and the duration of action is short, which makes it difficult to achieve high dose targeted delivery of hydrogen to the heart, seriously limiting the therapeutic potential of hydrogen for MI. As a result of reactions with the internal environment of the body, subcutaneous implantation of magnesium slices leads to continuous endogenous hydrogen production, leading to a higher hydrogen concentration and a longer duration of action in target organs. In this study, we propose magnesium implant-based hydrogen therapy for MI. After subcutaneous implantation of magnesium slices in the dorsum of rats, we measured hydrogen production and efficiency, and evaluated the safety of this approach. Compared with hydrogen inhalation, it significantly improved cardiac function in rats with MI. Magnesium implantation also cleared free radicals that were released as a result of mitochondrial dysfunction, as well as suppressing cardiomyocyte apoptosis.

Evolution and conservation genetics of pangolins

Pangolins (Pholidota, Manidae) are classified as an evolutionarily distinct and globally endangered mammal due to their unique morphology (nail-like scales and a myrmecophagous diet) and being the victim of heavy poaching and worldwide trafficking. As such, pangolins serve as a textbook example for studying the special phenotypic evolutionary adaptations and conservation genetics of an endangered species. Recent years have demonstrated significant advancements in the fields of molecular genetics and genomics, which have translated to a series of important research achievements and breakthroughs concerning the evolution and conservation genetics of pangolins. This review comprehensively presents the hitherto advances in phylogeny, adaptive evolution, conservation genetics, and conservation genomics that are related to pangolins, which will provide an ample understanding of their diversity, molecular adaptation mechanisms, and evolutionary potentials. In addition, we highlight the priority of investigating species/population diversity among pangolins and suggest several avenues of research that are highly relevant for future pangolin conservation.

Brushite-coated Mg-Nd-Zn-Zr alloy promotes the osteogenesis of vertebral laminae through IGF2/PI3K/AKT signaling pathway

Biodegradable magnesium (Mg) alloys have been extensively investigated in orthopedic implants due to their suitable mechanical strength and high biocompatibility. However, no studies have reported whether Mg alloys can be used to repair lamina defects, and the biological mechanisms regulating osteogenesis are not fully understood. The present study developed a lamina reconstruction device using our patented biodegradable Mg-Nd-Zn-Zr alloy (JDBM), and brushite (CaHPO₄·2H₂O, Dicalcium phosphate dihydrate, DCPD) coating was developed on the implant. Through in vitro and in vivo experiments, we evaluated the degradation behavior and biocompatibility of DCPD-JDBM. In addition, we explored the potential molecular mechanisms by which it regulates osteogenesis. In vitro, ion release and cytotoxicity tests revealed that DCPD-JDBM had better corrosion resistance and biocompatibility. We found that DCPD-JDBM extracts could promote MC3T3-E1 osteogenic differentiation via the IGF2/PI3K/AKT pathway. The lamina reconstruction device was implanted on a rat lumbar lamina defect model. Radiographic and histological analysis showed that DCPD-JDBM accelerated the repair of rat lamina defects and exhibited lower degradation rate compared to uncoated JDBM. Immunohistochemical and qRT-PCR results showed that DCPD-JDBM promoted osteogenesis in rat laminae via IGF2/PI3K/AKT pathway. This study shows that DCPD-JDBM is a promising biodegradable Mg-based material with great potential for clinical applications.

Applications of Biodegradable Magnesium-Based Materials in Reconstructive Oral and Maxillofacial Surgery: A Review

Reconstruction of defects in the maxillofacial region following traumatic injuries, craniofacial deformities, defects from tumor removal, or infections in the maxillofacial area represents a major challenge for surgeons. Various materials have been studied for the reconstruction of defects in the maxillofacial area. Biodegradable metals have been widely researched due to their excellent biological properties. Magnesium (Mg) and Mg-based materials have been extensively studied for tissue regeneration procedures due to biodegradability, mechanical characteristics, osteogenic capacity, biocompatibility, and antibacterial properties. The aim of this review was to analyze and discuss the applications of Mg and Mg-based materials in reconstructive oral and maxillofacial surgery in the fields of guided bone regeneration, dental implantology, fixation of facial bone fractures and soft tissue regeneration.

Research status of biodegradable metals designed for oral and maxillofacial applications: A review

The oral and maxillofacial regions have complex anatomical structures and different tissue types, which have vital health and aesthetic functions. Biodegradable metals (BMs) is a promising bioactive materials to treat oral and maxillofacial diseases. This review summarizes the research status and future research directions of BMs for oral and maxillofacial applications. Mg-based BMs and Zn-based BMs for bone fracture fixation systems, and guided bone regeneration (GBR) membranes, are discussed in detail. Zn-based BMs with a moderate degradation rate and superior mechanical properties for GBR membranes show great potential for clinical translation. Fe-based BMs have a relatively low degradation rate and insoluble degradation products, which greatly limit their application and clinical translation. Furthermore, we proposed potential future research directions for BMs in the oral and maxillofacial regions, including 3D printed BM bone scaffolds, surface modification for BMs GBR membranes, and BMs containing hydrogels for cartilage regeneration, soft tissue regeneration, and nerve regeneration. Taken together, the progress made in the development of BMs in oral and maxillofacial regions has laid a foundation for further clinical translation.

Controlled biodegradation of magnesium alloy in physiological environment by metal organic framework nanocomposite coatings

Magnesium-based implants (MBIs) have recently attracted great attention in bone regeneration due to elastic modulus similar to bone. Nevertheless, the degradation rate and hydrogen release of MBIs in the body have to be tackled for practical applications. In the present study, we present a metal–organic framework (MOF) nanoplates to reduce the degradation rate of AZ91 magnesium alloy. Zeolitic imidazolate frameworks (ZIF-8) with a specific surface area of 1789 m² g⁻¹ were prepared by solvothermal methods, and after dispersion in a chitosan solution (10% w/w), the suspension was electrospun on the surface of AZ91 alloy. Studying the degradation rate in simulated body fluid (SBF) by electrochemical analysis including potentiodynamic polarization and electrochemical impedance spectroscopy reveals that the degradation rate of the surface-modified implants decreases by ~ 80% as compared with the unmodified specimens. The reduced alkalization of the physiological environment and hydrogen release due to the implant degradation are shown. In vitro studies by fibroblasts and MG63 osteosarcoma cells exhibit improved cell adhesion and viability. The mechanisms behind the improved degradation resistance and enhanced bioactivity are presented and discussed. Surface modification of MBIs by MOF-chitosan coatings is a promising strategy to control the biodegradation of magnesium implants for bone regeneration.

Early osteoimmunomodulatory effects of magnesium-calcium-zinc alloys

Today, substantial attention is given to biomaterial strategies for bone regeneration, and among them, there is a growing interest in using immunomodulatory biomaterials. The ability of a biomaterial to induce neo vascularization and macrophage polarization is a major factor in defining its success. Magnesium (Mg)-based degradable alloys have attracted significant attention for bone regeneration owing to their biodegradability and potential for avoiding secondary removal surgeries. However, there is insufficient evidence in the literature regarding the early inflammatory responses to these alloys in vivo. In this study, we investigated the early body responses to Mg-0.45wt%Zn-0.45wt%Ca pin-shaped alloy (known as ZX00 alloy) in rat femora 2, 5, and 10 days after implantation. We used 3D micro computed tomography (µCT), histological, immunohistochemical, histomorphometrical, and small angle X-ray scattering (SAXS) analyses to study new bone formation, early macrophage polarization, neo vascularization, and bone quality at the implant bone interface. The expression of macrophage type 2 biological markers increased significantly after 10 days of Mg alloy implantation, indicating its potential in stimulating macrophage polarization. Our biomineralization results using µCT as well as histological stained sections did not indicate any statistically significant differences between different time points for both groups. The activity of alkaline phosphatase (ALP) and Runt-related transcription factor 2 (Runx 2) biological markers decreased significantly for Mg group, indicating less osteoblast activity. Generally, our results supported the potential of ZX00 alloy to enhance the expression of macrophage polarization in vivo; however, we could not observe any statistically significant changes regarding biomineralization.

In vivo evaluation of bending strengths and degradation rates of different magnesium pin designs for oral stapler

Magnesium alloys have been potential biodegradable implants in the areas of bone, cardiovascular system, gastrointestinal tract, and so on. The purpose of this study is to evaluate Mg-2Zn alloy degradation as a potential suture material. The study included Sprague-Dawley (SD) rats in vivo. In 24 male SD rats, tests in the leg muscle were conducted using traditional surgical incision and insertion of magnesium alloys of different designs into the tissue. The material degradation topography, elemental composition, and strength of the pins were analyzed. This paper explores magnesium pins with different cross-sectional shapes and diameters to establish a suitable pin diameter and shape for use as an oral stapler, which must have a good balance of degradation rate and strength. The results showed there were good bending strengths over different degradation periods in groups with diameters of 0.8 mm and 0.5 mm, and no significantly different bending strength between the groups of triangle and round cross-section shapes with same diameter of 0.3 mm, although the degradation rate still needs to be improved.

Biodegradable Magnesium-Based Implants in Orthopedics-A General Review and Perspectives

Biodegradable Mg-based metals may be promising orthopedic implants for treating challenging bone diseases, attributed to their desirable mechanical and osteopromotive properties. This Review summarizes the current status and future research trends for Mg-based orthopedic implants. First, the properties between Mg-based implants and traditional orthopedic implants are compared on the following aspects: in vitro and in vivo degradation mechanisms of Mg-based implants, peri-implant bone responses, the fate of the degradation products, and the cellular and molecular mechanisms underlying the beneficial effects of Mg ions on osteogenesis. Then, the preclinical studies conducted at the low weight bearing sites of animals are introduced. The innovative strategies (for example, via designing Mg-containing hybrid systems) are discussed to address the limitations of Mg-based metals prior to their clinical applications at weight-bearing sites. Finally, the available clinical studies are summarized and the challenges and perspectives of Mg-based orthopedic implants are discussed. Taken together, the progress made on the development of Mg-based implants in basic, translational, and clinical research has laid down a foundation for developing a new era in the treatment of challenging and prevalent bone diseases.

Engineered bio-nanocomposite magnesium scaffold for bone tissue regeneration

Porous magnesium based materials are gaining intensive potential as a substitute scaffold material in the field of biomedical engineering as their mechanical properties such as compressive strength and elastic modulus are quite similar to that of human bone. Considering the poor mechanical integrity of ceramic and polymeric materials, metallic implants such as magnesium based alloy foams can be used as a promising scaffold material for bone tissue engineering. Magnesium foams also have properties like excellent biocompatibility and biodegradability so that revision surgery can be completely eliminated after implantation in orthopaedic applications. Against this background, porous Mg alloy based bioactive nano-composite foams were developed. Nano-hydroxyapatite (n-HA) was used as bioactive reinforcement which was anticipated to enhance bone tissue regenerations. Magnesium based alloy compositions were developed by incorporating selective alloying elements, while the bioactive nano-composite foams were fabricated using powder metallurgy route. The powder metallurgy route involved sequential stages of mixing and compaction of all powders with carbamide powder as a space holding material, followed by sintering of the green compacts. The microstructures of these nano-ceramic reinforced metal matrix foams were studied by scanning electron microscopy (SEM) in combination with energy dispersive X-ray spectroscopy (EDS), X-ray diffraction (XRD) and X-ray micro computed tomography (X-ray micro CT). Further, mechanical properties of the nanocomposite foams were evaluated. SEM and EDS results confirmed a homogeneous distribution of pores, alloying elements and n-HA. Structure-property correlations were established through the microstructural characterizations. The study therefore demonstrated that selected Mg alloy based composite foam can be an excellent candidate material for bone tissue engineering.

Treatment of trauma-induced femoral head necrosis with biodegradable pure Mg screw-fixed pedicle iliac bone flap

Introduction

The avascular necrosis of the femoral head represents the death of bone tissue due to the lack of blood supply. The disease has a progressive evolution; it leads to femoral head collapse and severe arthritis when left untreated. The application of a pedicled bone flap graft is an effective treatment for femoral head necrosis. A pure Mg screw is a kind of degradable screw that can fix the grafted bone flap and prevent long-term stress occlusion and secondary dissection.

Case presentation

The report shows the results of the treatment of traumatic femoral head necrosis with a pedicled bone flap with pure Mg screw. A patient had avascular necrosis of the femoral head after 2 years of internal fixation of the femoral neck fracture. We removed the patient's internal fixation hollow nail, cleaned the necrotic bone tissue and took part of the same ipsilateral pedicle iliac bone graft in the femoral head defect with biodegradable pure Mg screw fixation. Within 2 years after the surgery, the patients had no significant progressive necrosis of the femoral head. Postoperative Harris scores showed that the patient's left hip function was significantly improved compared with his preoperative state. The pure Mg screw in the body had gradually degraded. After 2 years, the screw's diameter had been significantly reduced compared with 3 days after the surgery. The postoperative Harris score showed that the patient's left hip function was significantly improved compared with the second preoperative examination.

Discussion

The discussion includes the reasons for the choices of surgical approaches, the mode of pure Mg screw degradation and the postoperative functional assessment of the patient's left hip.

Conclusion

Pure Mg screw fixation pedicled bone flap transplantation is an effective surgical treatment for femoral head necrosis in young patients. Pure Mg screw is a biodegradable internal fixation device with good biocompatibility, which has a good clinical application prospects.

The translational potential of this article

Degradable pure Mg screw has the potential to preserve hip joint therapy for the treatment of femoral head necrosis.

Magnesium (Mg) based interference screws developed for promoting tendon graft incorporation in bone tunnel in rabbits

How to enhance tendon graft incorporation into bone tunnels for achieving satisfactory healing outcomes in patients with anterior cruciate ligament reconstruction (ACLR) is one of the most challenging clinical problems in orthopaedic sports medicine. Several studies have recently reported the beneficial effects of Mg implants in bone fracture healing, indicating the use potential of Mg devices in promoting the tendon graft osteointegration. Here, we developed an innovative Mg-based interference screws for fixation of the tendon graft in rabbits underwent ACLR and investigated the biological role of Mg-based implants in the graft healing. The titanium (Ti) interference screw was used as the control. We demonstrated that Mg interference screw significantly accelerated the incorporation of the tendon graft into bone tunnels via multiscale analytical methods including scanning electronic microscopy/energy dispersive spectrometer (SEM/EDS), micro-hardness, micro-Fourier transform infrared spectroscopy (μFTIR), and histology. Our in vivo study showed that Mg implants enhanced the recruitment of bone marrow stromal stem cells (BMSCs) towards peri-implant bone tissue, which may be ascribed to the upregulation of local TGF-β1 and PDGF-BB. Besides, the in vitro study revealed that higher Mg ions was beneficial to the improvement of capability in cell adhesion and osteogenic differentiation of BMSCs. Thus, the enhancement in cell migration, cell adhesion and osteogenic differentiation of BMSCs may contribute to an improved tendon graft osteointegration in the Mg group. Our findings in this work may further facilitate clinical applications of Mg-based interference screws for enhancing tendon graft-bone junction healing in patients indicated for ACLR.

STATEMENT OF SIGNIFICANCE

How to promote tendon-bone junction healing is one of the major challenging issues for satisfactory clinical outcomes in patients after ACL reconstruction. The improvement of bony ingrowth into the tendon graft-bone interface can enhance the tendon graft osteointegration. In this study, we applied Mg based interference screws to fix the tendon graft in rabbits and found the use of Mg screws could accelerate and significantly increase mineralized matrix formation at the tendon-bone interface in animals when compared to those with Ti screws. We elucidated the mechanism behind the favorable effects of Mg screws on the graft healing in both in vitro and in vivo studies from multiscale technologies. The optimized interface structure and function in Mg group may be ascribed to the improved cell migration capability, enhanced cell adhesion strength and promoted osteogenic differentiation ability of BMSCs under the stimuli of Mg ions degraded from implanted Mg screws. Our findings may help us broaden our thinking in the application potential of Mg interference screws in future clinical trials.

The potential of isotopically enriched magnesium to study bone implant degradation in vivo

This pilot study highlights the substantial potential of using isotopically enriched (non-radioactive) metals to study the fate of biodegradable metal implants. It was possible to show that magnesium (Mg) release can be observed by combining isotopic mass spectrometry and isotopic pattern deconvolution for data reduction, even at low amounts of Mg released a from slowly degrading ²⁶Mg enriched (>99%) Mg metal. Following implantation into rats, structural in vivo changes were monitored by μCT. Results showed that the applied Mg had an average degradation rate of 16±5μmyear^-1, which corresponds with the degradation rate of pure Mg. Bone and tissue extraction was performed 4, 24, and 52weeks after implantation. Bone cross sections were analyzed by laser ablation inductively coupled plasma mass spectrometry (ICP-MS) to determine the lateral ²⁶Mg distribution. The ²⁶Mg/²⁴Mg ratios in digested tissue and excretion samples were analyzed by multi collector ICP-MS. Isotope pattern deconvolution in combination with ICP-MS enabled detection of Mg pin material in amounts as low as 200ppm in bone tissues and 20ppm in tissues up to two fold increased Mg levels with a contribution of pin-derived Mg of up to 75% (4weeks) and 30% (24weeks) were found adjacent to the implant. After complete degradation, no visual bone disturbance or residual pin-Mg could be detected in cortical bone. In organs, increased Δ²⁶Mg/²⁴Mg values up to 16‰ were determined compared to control samples. Increased Δ²⁶Mg/²⁴Mg values were detected in serum samples at a constant total Mg level. In contrast to urine, feces did not show a shift in the ²⁶Mg/²⁴Mg ratios. This investigation showed that the organism is capable of handling excess Mg well and that bones fully recover after degradation.

STATEMENT OF SIGNIFICANCE

Magnesium alloys as bone implants have faced increasing attention over the past years. In vivo degradation and metabolism studies of these implant materials have shown the promising application in orthopaedic trauma surgery. With advance in Mg research it has become increasingly important to monitor the fate of the implant material in the organism. For the first time, the indispensible potential of isotopically enriched materials is documented by applying ²⁶Mg enriched Mg implants in an animal model. Therefore, the spatial distribution of pin-Mg in bone and the pin-Mg migration and excretion in the organism could be monitored to better understand metal degradation as well as Mg turn over and excretion.

Novel Bio-functional Magnesium Coating on Porous Ti6Al4V Orthopaedic Implants: In vitro and In vivo Study

Titanium and its alloys with various porous structures are one of the most important metals used in orthopaedic implants due to favourable properties as replacement for hard tissues. However, surface modification is critical to improve the osteointegration of titanium and its alloys. In this study, a bioactive magnesium coating was successfully fabricated on porous Ti6Al4V by means of arc ion plating, which was proved with fine grain size and high film/substrate adhesion. The surface composition and morphology were characterized by X-ray diffraction and SEM equipped with energy dispersive spectroscopy. Furthermore, the in vitro study of cytotoxicity and proliferation of MC3T3-E1 cells showed that magnesium coated porous Ti6Al4V had suitable degradation and biocompatibility. Moreover, the in vivo studies including fluorescent labelling, micro-computed tomography analysis scan and Van-Gieson staining of histological sections indicated that magnesium coated porous Ti6Al4V could significantly promote bone regeneration in rabbit femoral condylar defects after implantation for 4 and 8 weeks, and has better osteogenesis and osteointegration than the bare porous Ti6Al4V. Therefore, it is expected that this bioactive magnesium coating on porous Ti6Al4V scaffolds with improved osteointegration and osteogenesis functions can be used for orthopedic applications.

Biodegradable Magnesium Screws Accelerate Fibrous Tissue Mineralization at the Tendon-Bone Insertion in Anterior Cruciate Ligament Reconstruction Model of Rabbit

The incorporation of tendon graft into bone tunnel is one of the most challenging clinical issues in anterior cruciate ligament (ACL) reconstruction. As a biodegradable metal, Mg has appropriate mechanical strength and osteoinductive effects, thus may be a promising alternative to commercialized products used for graft fixation. Therefore, it was hypothesized that Mg based interference screws would promote tendon graft-bone junction healing when compared to Ti screws. Herein, we compared the effects of Mg and Ti screws on tendon graft healing in rabbits with ACL reconstruction via histological, HR-pQCT and mechanical analysis. The histological results indicated that Mg screws significantly improved the graft healing quality via promoting mineralization at the tendon graft enthesis. Besides, Mg screws significantly promoted bone formation in the peri-screw region at the early healing stage. Importantly, Mg screws exhibited excellent corrosion resistance and the degradation of Mg screws did not induce bone tunnel widening. In tensile testing, there were no significant differences in the load to failure, stress, stiffness and absorption energy between Mg and Ti groups due to the failure mode at the midsubstance. Our findings demonstrate that Mg screws can promote tendon graft healing after ACL reconstruction, implying a potential alternative to Ti screws for clinical applications.

Current status on clinical applications of magnesium-based orthopaedic implants: A review from clinical translational perspective

As a new generation of medical metallic material, magnesium (Mg) and its alloys with or without surface coating have attracted a great deal of attention due to its biodegradability and potential for avoiding a removal operation after the implant has fulfilled its function for surgical fixation of injured musculoskeletal tissues. Although a few clinical cases on Mg-based orthopaedic implants were reported more than a century ago, it was not until recently that clinical trials using these implants with improved physicochemical properties were carried out in Germany, China and Korea for bone fracture fixation. The promising results so far suggest a bright future for biodegradable Mg-based orthopaedic implants and would warrant large scale phase II/III studies. Given the increasing interest on this emerging biomaterials and intense effort to improve its properties for various clinical applications, this review covers the evolution, current strategies, and future perspectives in the development of Mg-based orthopaedic implants. We also highlight a few clinical cases performed in China that may be unfamiliar to the general orthopaedic community.