Due to their good properties of elastic modulus, degradability and ability to promote bone repair, magnesium alloys have become a research hotspot in research of orthopedic implants. Nevertheless, most of the biomedical magnesium alloys currently available fail to meet the requirements in orthopedics because of their rapid degradation after implantation. Rare earth-magnesium alloys possess excellent corrosion resistance and are expected to become important materials as clinical orthopedic implants. This review summarizes the recent progress in studies of the physiological functions of rare earth elements, the effects of supplementation of rare earth elements on biomechanical properties and the in vitro and in vivo biocompatibility of magnesium alloys, and their contribution to tendon-bone healing, addressing also the current clinical orthopedic applications of different rare earth-magnesium alloys, challenges, and future strategies for improving these alloys.
Alloys/chemistry* ; Magnesium/chemistry* ; Metals, Rare Earth/chemistry* ; Humans ; Biocompatible Materials ; Prostheses and Implants

The evaluation of blood compatibility of biomaterials is crucial for ensuring the clinical safety of implantable medical devices. To address the limitations of traditional testing methods in real-time monitoring and electrical property analysis, this study developed a portable electrical impedance tomography (EIT) system. The system uses a 16-electrode design, operates within a frequency range of 1 to 500 kHz, achieves a signal to noise ratio (SNR) of 69.54 dB at 50 kHz, and has a data collection speed of 20 frames per second. Experimental results show that the EIT system developed in this study is highly consistent with a microplate reader ( R ²=0.97) in detecting the hemolytic behavior of industrial-grade titanium (TA3) and titanium alloy-titanium 6 aluminum 4 vanadium (TC4) in anticoagulated bovine blood. Additionally, with the support of a multimodal image fusion Gauss-Newton one-step iterative algorithm, the system can accurately locate and monitor in real-time the dynamic changes in blood permeation and coagulation caused by TC4 in vivo. In conclusion, the EIT system developed in this study provides a new and effective method for evaluating the blood compatibility of biomaterials.
Electric Impedance ; Animals ; Tomography/instrumentation* ; Biocompatible Materials ; Materials Testing/instrumentation* ; Cattle ; Titanium ; Alloys ; Prostheses and Implants

OBJECTIVE: To evaluate the effect of biodegradable magnesium alloy materials in promoting tendon-bone healing during rotator cuff tear repair and to investigate their potential underlying biological mechanisms. METHODS: Forty-eight 8-week-old Sprague Dawley rats were taken and randomly divided into groups A, B, and C. Rotator cuff tear models were created and repaired using magnesium alloy sutures in group A and Vicryl Plus 4-0 absorbable sutures in group B, while only subcutaneous incisions and sutures were performed in group C. Organ samples of groups A and B were taken for HE staining at 1 and 2 weeks after operation to evaluate the safety of magnesium alloy, and specimens from the supraspinatus tendon and proximal humerus were harvested at 2, 4, 8, and 12 weeks after operation. The specimens were observed macroscopically at 4 and 12 weeks after operation. Biomechanical tests were performed at 4, 8, and 12 weeks to test the ultimate load and stiffness of the healing sites in groups A and B. At 2, 4, and 12 weeks, the specimens were subjected to the following tests: Micro-CT to evaluate the formation of bone tunnels in groups A and B, HE staining and Masson staining to observe the regeneration of fibrocartilage at the tendon-bone interface after decalcification and sectioning, and Goldner trichrome staining to evaluate the calcification. Immunohistochemical staining was performed to detect the expressions of angiogenic factors, including vascular endothelial growth factor (VEGF) and bone morphogenetic protein 2 (BMP-2), as well as osteogenic factors at the tendon-bone interface. Additionally, immunofluorescence staining was used to examine the expressions of Arginase 1 and Integrin beta-2 to assess M1 and M2 macrophage polarization at the tendon-bone interface. The role of the phosphatidylinositol 3-kinase (PI3K)/protein kinase B (AKT) signaling pathway in tendon-bone healing was further analyzed using real-time fluorescence quantitative PCR. RESULTS: Analysis of visceral sections revealed that magnesium ions released during the degradation of magnesium alloys did not cause significant toxic effects on organs such as the heart, liver, spleen, lungs, and kidneys, indicating good biosafety. Histological analysis further demonstrated that fibrocartilage regeneration at the tendon-bone interface in group A occurred earlier, and the amount of fibrocartilage was significantly greater compared to group B, suggesting a positive effect of magnesium alloy material on tendon-bone interface repair. Additionally, Micro-CT analysis results revealed that bone tunnel formation occurred more rapidly in group A compared to group B, further supporting the beneficial effect of magnesium alloy on bone healing. Biomechanical testing showed that the ultimate load in group A was consistently higher than in group B, and the stiffness of group A was also greater than that of group B at 4 weeks, indicating stronger tissue-carrying capacity following tendon-bone interface repair and highlighting the potential of magnesium alloy in enhancing tendon-bone healing. Immunohistochemical staining results indicated that the expressions of VEGF and BMP-2 were significantly upregulated during the early stages of healing, suggesting that magnesium alloy effectively promoted angiogenesis and bone formation, thereby accelerating the tendon-bone healing process. Immunofluorescence staining further revealed that magnesium ions exerted significant anti-inflammatory effects by regulating macrophage polarization, promoting their shift toward the M2 phenotype. Real-time fluorescence quantitative PCR results demonstrated that magnesium ions could facilitate tendon-bone healing by modulating the PI3K/AKT signaling pathway. CONCLUSION Biodegradable magnesium alloy material accelerated fibrocartilage regeneration and calcification at the tendon-bone interface in rat rotator cuff tear repair by regulating the PI3K/AKT signaling pathway, thereby significantly enhancing tendon-bone healing.
Animals ; Rotator Cuff Injuries/metabolism* ; Rats, Sprague-Dawley ; Signal Transduction ; Wound Healing/drug effects* ; Alloys/pharmacology* ; Rats ; Proto-Oncogene Proteins c-akt/metabolism* ; Rotator Cuff/metabolism* ; Macrophages/metabolism* ; Magnesium/pharmacology* ; Phosphatidylinositol 3-Kinases/metabolism* ; Vascular Endothelial Growth Factor A/metabolism* ; Male ; Biocompatible Materials ; Bone Morphogenetic Protein 2/metabolism*

OBJECTIVE: We aimed to investigate the patterns of fasting blood glucose (FBG) trajectories and analyze the relationship between various occupational hazard factors and FBG trajectories in male steelworkers. METHODS: The study cohort included 3,728 workers who met the selection criteria for the Tanggang Occupational Cohort (TGOC) between 2017 and 2022. A group-based trajectory model was used to identify the FBG trajectories. Environmental risk scores (ERS) were constructed using regression coefficients from the occupational hazard model as weights. Univariate and multivariate logistic regression analyses were performed to explore the effects of occupational hazard factors using the ERS on FBG trajectories. RESULTS: FBG trajectories were categorized into three groups. An association was observed between high temperature, noise exposure, and FBG trajectory ( P < 0.05). Using the first quartile group of ERS1 as a reference, the fourth quartile group of ERS1 had an increased risk of medium and high FBG by 1.90 and 2.21 times, respectively (odds ratio [ OR] = 1.90, 95% confidence interval [ CI]: 1.17-3.10; OR = 2.21, 95% CI: 1.09-4.45). CONCLUSION An association was observed between occupational hazards based on ERS and FBG trajectories. The risk of FBG trajectory levels increase with an increase in ERS.
Humans ; Male ; Adult ; Blood Glucose/analysis* ; China ; Prospective Studies ; Occupational Exposure/adverse effects* ; Risk Factors ; Middle Aged ; Steel ; Fasting/blood* ; Metal Workers ; East Asian People

OBJECTIVE: To evaluate the short-term effectiveness of Ilizarov technique combined with steel needle internal fixation in treating Charcot neuroarthropathy (CN) of the foot and ankle. METHODS: Between June 2020 and December 2023, 12 patients with Eichenholtz stage Ⅲ CN of the foot and ankle were treated with Ilizarov technique and steel needle internal fixation. There were 9 males and 3 females with an average age of 48.6 years (range, 19-66 years). The disease duration ranged from 1 to 16 months (mean, 6.8 months). Ankle joint involvement predominated in 7 cases, while midfoot involvement occurred in 5 cases; 3 cases presented with skin ulceration and soft tissue infection. Preoperative American Orthopedic Foot and Ankle Society (AOFAS) score was 31.2±9.0, 36-Item Short-Form Health Survey (SF-36)-Physical Component Summary (PCS) score was 32.6±6.8, and Mental Component Summary (MCS) score was 47.8±8.4. Postoperative assessments included wound healing, regular X-ray film/CT evaluations of fusion status, and effectiveness via AOFAS and SF-36-PCS, MCS scores. RESULTS: All operations were successfully completed without neurovascular complication. Two patients experienced delayed wound healing requiring intervention, and the others achieved primary healing. All patients were followed up 15-43 months (mean, 23.3 months). Imaging confirmed successful joint fusion within 13-21 weeks (mean, 16.8 weeks). At last follow-up, the AOFAS score was 72.5±6.4, and the SF-36-PCS and MCS scores were 63.2±8.4 and 76.7±5.3, respectively, all of which improved compared to preoperative levels, with significant differences ( P<0.05). CONCLUSION Ilizarov technique combined with steel needle internal fixation effectively restores walking function and achieves satisfactory short-term effectiveness in CN of the foot and ankle.
Humans ; Middle Aged ; Male ; Female ; Adult ; Ilizarov Technique ; Arthropathy, Neurogenic/surgery* ; Aged ; Ankle Joint/surgery* ; Treatment Outcome ; Needles ; Fracture Fixation, Internal/instrumentation* ; Steel ; Young Adult ; Foot Joints/surgery*

OBJECTIVE: To explore the effectiveness of additional anti-rotation steel plate assisted intramedullary nail technology in treatment of aseptic femoral non-union patients. METHODS: A retrospective analysis was conducted on 21 patients with aseptic femoral non-union who admitted between September 2020 and October 2024 and treated with additional anti-rotation steel plate assisted intramedullary nail technology. There were 17 males and 4 females, aged 25-67 years (mean, 44 years). There were 19 cases of femoral anterograde intramedullary nail fixation, 1 case of femoral retrograde intramedullary nail fixation, and 1 case of steel plate fixation with fatigue fracture. There were 9 cases of hypertrophic non-union and 12 cases of atrophic non-union. All patients had varying degrees of fracture end atrophy/sclerosis. Among them, 20 patients who were fixed with intramedullary nails underwent removal of soft tissue and hardened bone at the fracture end, and cortical treatment resulted in the appearance of "chili sign" at the fracture end. Iliac bone grafting and anti-rotation steel plate fixation were performed. One patient with steel plate fixation was removed the steel palte and fixed with a retrograde intramedullary nail, while the hardened bone at the fracture end was removed, iliac bone grafting and anti-rotation steel plate fixation were performed. Postoperative follow-up observation included the incision healing, maximum knee flexion range of motion, bone healing, length of lower limbs, and subjective satisfaction. The lower extremity functional scale (LEFS) score was used to evaluate the lower limb function. RESULTS: All incisions healed by first intention. All patients were followed up 7-26 months (mean, 15.5 months). At last follow-up, the femoral fracture healed with the obvious callus formation at the fracture end; the maximum knee flexion range of motion was 95°-127° (mean, 112.67°). The LEFS score increased from 29.9±6.7 before operation to 75.9±3.0 at last follow-up, and the difference was significant (t=-29.622, P<0.001). Except for 1 patient who underwent intramedullary nail dynamic treatment before operation and had a lower limb shortening of about 0.9 cm, the other patients had bilateral lower limbs of equal length. All patients had no postoperative infections, mal-union of fractures, deep vein thrombosis, joint stiffness, or other complications. CONCLUSION The use of additional anti-rotation steel plate assisted intramedullary nail technology in the treatment of aseptic femoral non-union not only overcomes the drawbacks of insufficient stability at the fracture end of intramedullary nails, but also overcomes the shortcomings of biased fixation with steel plates. It has the advantages of minimal trauma, effective maintenance of fracture stability, and ideal postoperative functional recovery, making it an effective treatment for aseptic femoral non-union.
Humans ; Male ; Fracture Fixation, Intramedullary/instrumentation* ; Female ; Bone Plates ; Middle Aged ; Adult ; Femoral Fractures/surgery* ; Retrospective Studies ; Bone Nails ; Aged ; Fractures, Ununited/surgery* ; Treatment Outcome ; Bone Transplantation/methods* ; Steel ; Fracture Healing

OBJECTIVE: To review the application progress of customized steel plates in osteotomy and orthopedic treatment for knee osteoarthritis (KOA), and provide reference for orthopedic surgeons and researchers. METHODS: Extensive review of the literature on customized steel plates for osteotomies and knee-preserving surgeries for KOA, 2015-2025, with an overview of the principles of customized steel plate design, clinical applications, and future directions, describing their advantages and shortcomings. RESULTS: Customized steel plates have demonstrated many advantages in osteotomy and orthopedic treatment of KOA, which not only enhance surgical outcomes and optimize mechanical properties, but also reduce the incidence of postoperative complications. However, high cost, long manufacturing period, and selection of patient indications are still important factors restricting their use. CONCLUSION Customized steel plates show promising potential in treating KOA. Not only do they reduce surgical duration and enhance postoperative healing outcomes, but they also effectively lower the incidence of postoperative complications, thereby improving patients' quality of life.
Humans ; Osteoarthritis, Knee/surgery* ; Osteotomy/methods* ; Bone Plates ; Postoperative Complications/epidemiology* ; Steel ; Quality of Life ; Treatment Outcome ; Knee Joint/surgery*

OBJECTIVE: To investigate the biocompatibility of porous WE43 magnesium alloy scaffolds manufactured by 3D printing technology and to observe its effect in treating femoral defects in New Zealand white rabbits. METHODS: In vitro cytotoxicity test was performed using bone marrow mesenchymal stem cells from Sprague Dawley (S-D) rats. According to the different culture media, the cells were divided into 100% extract group, 50% extract group, 10% extract group and control group. After culturing for 1, 3 and 7 days, the cell activity of each group was determined by cell counting kit-8 (CCK-8). In the in vivo experiment, 3.0-3.5 kg New Zealand white rabbits were randomly divided into three groups: Experimental group, bone cement group and blank group, with 9 rabbits in each group. Each rabbit underwent surgery on the left lateral femoral condyle, and a bone defect with a diameter of 5 mm and a depth of 6 mm was created using a bone drill. The experimental group was implanted with WE43 magnesium alloy scaffolds, the bone cement group was implanted with calcium sulfate bone cement, and the blank group was not implanted. Then 4, 8 and 12 weeks after surgery, 3 rabbits in each group were euthanized by carbon dioxide anesthesia, and the femur and important internal organs were sampled. Micro-computed tomography (Micro-CT) scanning was performed on the left lateral femoral condyle. Sections of important internal organs were prepared and stained with hematoxylin-eosin (HE). Hard tissue sections were made from the left lateral femoral condyle and stained with methylene blue acid fuchsin and observed under a microscope. RESULTS: In the cytotoxicity test, the cell survival rate in the 100% extract group was higher than that in the control group (140.56% vs. 100.00%, P < 0.05) on 1 day of culture; there was no statistically significant difference (P>0.05) in cell survival rate among the groups on 3 days of culture; the cell survival rate in the 100% extract group was lower than that in the control group (68.64% vs. 100.00%, P < 0.05) on 7 days of culture. Micro-CT scanning in the in vivo experiment found that most of the scaffolds in the experimental group had been degraded in 4 weeks, with very few high-density scaffolds remaining. In 12 weeks, there was no obvious stent outline. In 4 weeks, a certain amount of gas was generated around the WE43 magnesium alloy scaffold, and the gas was significantly reduced from 8 to 12 weeks. Hard tissue sections showed that a certain amount of extracellular matrix and osteoid were generated around the scaffolds in the experimental group in 4 weeks. In the bone cement group, most of the calcium sulfate bone cement had been degraded. In 8 weeks, the osteoid around the scaffold and its degradation products in the experimental group increased significantly. In 12 weeks, new bone was in contact with the scaffold around the scaffold in the experimental group. There was less new bone in the bone cement group and the blank group. CONCLUSION The porous WE43 magnesium alloy scaffold fabricated by 3D printing process has good biocompatibility and good osteogenic properties, and has the potential to become a new material for repairing bone defects.
Animals ; Rabbits ; Printing, Three-Dimensional ; Alloys/chemistry* ; Tissue Scaffolds/chemistry* ; Magnesium/chemistry* ; Rats, Sprague-Dawley ; Biocompatible Materials ; Mesenchymal Stem Cells/cytology* ; Femur/surgery* ; Rats ; Absorbable Implants ; Male ; Bone Regeneration ; Tissue Engineering/methods* ; Cells, Cultured

In this paper, a preliminary stress/strain analysis of the design structure of a nickel-titanium alloy patent foramen ovale occluder is conducted with the finite element simulation analysis method. In the analysis, solid structure modeling is carried out on three different specifications of domestic patent foramen ovale occluders. Referring to the test method of fatigue performance in inspection standard YY/T 1553-2017, an initial installation deformation is applied to the model, and then the fatigue displacement of 2 mm is applied to the sample to make the model fatigue deformation. The fatigue safety factors of each type of occluder are obtained by strain simulation analysis. The results indicate that the minimum fatigue safety factors of the three specifications of domestic patent foramen ovale occluders are 2.09, 2.35 and 2.06 respectively, which all meet the design of fatigue safety factor greater than 1. Among them, 1818 and 3030 specifications of patent foramen ovale occluders have close values in minimum fatigue safety factors, and both are lower than that of 1825 model. Therefore, it is recommended to carry out physical fatigue tests on both 1818 and 3030 specifications to further verify the fatigue performance of the products.
Finite Element Analysis ; Titanium ; Nickel ; Alloys ; Foramen Ovale, Patent ; Materials Testing ; Septal Occluder Device ; Stress, Mechanical

Vascular stents are an essential tool in cardiovascular interventional therapy, and their demand is growing with the increasing incidence of cardiovascular diseases. Compared with permanent stents, which are prone to in-stent restenosis, and drug-eluting stents, which may cause late stent thrombosis, biodegradable stents offer advantages. After providing early radial support to prevent elastic recoil, biodegradable stents gradually degrade, allowing the vessel to regain its natural physiological contractility and undergo positive remodeling. A review of the current mainstream biodegradable metal stents, magnesium-based, iron-based, and zinc-based alloys, shows promising findings in both preclinical and clinical research. Magnesium-based stents exhibit good operability and low thrombosis rates, but their limitations include rapid degradation, hydrogen evolution, and significant pH changes in the microenvironment. Iron-based stents demonstrate excellent mechanical strength, formability, biocompatibility, and hemocompatibility, but their slow corrosion rate hampers broader clinical application; accelerating degradation remains key. Zinc-based alloys have a moderate degradation rate but relatively low mechanical strength; enhancing stent strength by alloying with other elements is the main improvement direction for zinc-based stents.
Humans ; Absorbable Implants ; Stents ; Alloys/chemistry* ; Magnesium/chemistry* ; Biocompatible Materials/chemistry* ; Zinc/chemistry* ; Drug-Eluting Stents ; Iron/chemistry* ; Metals/chemistry*