[Research progress in surgical treatment of avascular necrosis of talus].

Objective: To summarize the surgical treatment methods for avascular necrosis of the talus. Methods: The recent domestic and international literature related to avascular necrosis of the talus was extensively conducted. The pathogenesis, surgical treatment methods, and prognosis were summarized. Results: The clinical symptoms of avascular necrosis of the talus at early stage are not obvious, and most patients have progressed to Ficat-Arlet stages Ⅲ-Ⅳ and require surgical treatment. Currently, surgical treatments for this disease include core decompression, vascularized bone flap transplantation, arthroplasty, and arthrodesis, etc. Early avascular necrosis of the talus can be treated conservatively, and if treatment fails, core decompression can be considered. Arthrodesis is a remedial surgery for patients with end-stage arthritis and collapse, and in cases of severe bone loss, tibiotalocalcaneal arthrodesis and bone grafting are required. Vascularized bone flap transplantation is effective and plays a role in all stages of avascular necrosis of the talus, but the appropriate donor area for the flap still needs further to be studied. Conclusion: The surgical treatment and the system of treatment for different stages of avascular necrosis of the talus still need to be refined.

Boosted charge transfer in a naturally formed Ca(Al2Si2O8)/Fe2O3 heterojunction for piezocatalytical formation of H2O2 and solidification of U(VI).

Energy and environmental issues make the generation of H2O2 and the separation of U(VI) from water very important topics. In this work, we disclosed a low-cost, high-efficiency method for separating U(VI) from water based on the naturally formed catalyst (red volcanic stone powders, RVSP) of Ca(Al2Si2O8)/Fe2O3 heterojunction through a piezocatalytic pathway induced by ultrasonication. The charges were found to be elevatedly separated due to the formation of the heterojunction. It is found that under ultrasonication, charges were effectively separated and then reacted with water to form H2O2 with a high yield of 196.7 µmol·g-1 in 4 h, which further solidifies U(VI) to form a solid of UO2O2. The removal rate of U(VI) in water reached 96 % (50 ppm) within 150 min. Furthermore, the results calculated by VASP show that the cyclic variation of the conduction bands under a cyclic force field facilitates the charge separation, and thus may promote piezocatalysis. Most importantly, the application study in real seawater indicates that U(VI) piezocatalysis based on natural minerals has great potential. This work presents a comprehensive investigation of U(VI) piezocatalysis by Ca(Al2Si2O8)/Fe2O3 and provides a new idea for piezocatalytic extraction of uranium.

Principles and clinical applications of transcutaneous laser-assisted drug delivery: A narrative review.

Introduction: Transcutaneous laser-assisted drug delivery (LADD) is recognized as a developing therapy for skin disorders. Method: Current literature was reviewed to summarize current applications for LADD. Discussion: 12 clinical applications for this therapy are currently reported. Conclusion: LADD has potential for wide application in skin disorder treatment. Lay Summary: Laser assisted drug delivery improves drug bioavailability for treatment of skin disorders. This technique is being assessed clinically in disorders ranging from skin cancers to alopecia.

Extracellular vesicles derived from mesenchymal stem cells mediate extracellular matrix remodeling in osteoarthritis through the transport of microRNA-29a.

BACKGROUND: Knee osteoarthritis (KOA) is a common orthopedic condition with an uncertain etiology, possibly involving genetics and biomechanics. Factors like changes in chondrocyte microenvironment, oxidative stress, inflammation, and immune responses affect KOA development. Early-stage treatment options primarily target symptom relief. Mesenchymal stem cells (MSCs) show promise for treatment, despite challenges. Recent research highlights microRNAs (miRNAs) within MSC-released extracellular vesicles that can potentially promote cartilage regeneration and hinder KOA progression. This suggests exosomes (Exos) as a promising avenue for future treatment. While these findings emphasize the need for effective KOA progression management, further safety and efficacy validation for Exos is essential. AIM: To explore miR-29a's role in KOA, we'll create miR-29a-loaded vesicles, testing for early treatment in rat models. METHODS: Extraction of bone marrow MSC-derived extracellular vesicles, preparation of engineered vesicles loaded with miR-29a using ultrasonication, and identification using quantitative reverse transcription polymerase chain reaction; after establishing a rat model of KOA, rats were randomly divided into three groups: Blank control group injected with saline, normal extracellular vesicle group injected with normal extracellular vesicle suspension, and engineered extracellular vesicle group injected with engineered extracellular vesicle suspension. The three groups were subjected to general behavioral observation analysis, imaging evaluation, gross histological observation evaluation, histological detection, and immunohistochemical detection to compare and evaluate the progress of various forms of arthritis. RESULTS: General behavioral observation results showed that the extracellular vesicle group and engineered extracellular vesicle group had better performance in all four indicators of pain, gait, joint mobility, and swelling compared to the blank control group. Additionally, the engineered extracellular vesicle group had better pain relief at 4 wk and better knee joint mobility at 8 wk compared to the normal extracellular vesicle group. Imaging examination results showed that the blank control group had the fastest progression of arthritis, the normal extracellular vesicle group had a relatively slower progression, and the engineered extracellular vesicle group had the slowest progression. Gross histological observation results showed that the blank control group had the most obvious signs of arthritis, the normal extracellular vesicle group showed signs of arthritis, and the engineered extracellular vesicle group showed no significant signs of arthritis. Using the Pelletier gross score evaluation, the engineered extracellular vesicle group had the slowest progression of arthritis. Results from two types of staining showed that the articular cartilage of rats in the normal extracellular vesicle and engineered extracellular vesicle groups was significantly better than that of the blank control group, and the engineered extracellular vesicle group had the best cartilage cell and joint surface condition. Immunohistochemical detection of type II collagen and proteoglycan showed that the extracellular matrix of cartilage cells in the normal extracellular vesicle and engineered extracellular vesicle groups was better than that of the blank control group. Compared to the normal extracellular vesicle group, the engineered extracellular vesicle group had a better regulatory effect on the extracellular matrix of cartilage cells. CONCLUSION: Engineered Exos loaded with miR-29a can exert anti-inflammatory effects and maintain extracellular matrix stability, thereby protecting articular cartilage, and slowing the progression of KOA.

Advances in the Application of Bone Transport Techniques in the Treatment of Bone Nonunion and Bone Defects.

Bone nonunion and bone defects frequently occur following high-energy open injuries or debridement surgeries, presenting complex challenges to treatment and significantly affecting patients' quality of life. At present, there are three primary treatment options available for addressing bone nonunion and bone defects: vascularized bone grafts, the Masquelet technique, and the Ilizarov technique. The Ilizarov technique, also known as distraction osteogenesis, is widely favored by orthopedic surgeons because of several advantages, including minimal soft tissue requirements, low infection risk, and short consolidation time. However, in recent years, the application of the Masquelet technique has resulted in novel treatment methods for managing post-traumatic bone infections when bone defects are present. Although these new techniques do not constitute a panacea, they continue to be the most commonly employed options for treating complex large bone nonunion and bone defects. This review evaluates the currently available research on the Ilizarov and Masquelet bone transport techniques applied at various anatomical sites. Additionally, it explores treatment durations and associated complications to establish a theoretical foundation that can guide clinical treatment decisions and surgical procedures for the management of bone nonunion and bone defects.

Cataract, glaucoma, and diabetic retinopathy are independent risk factors affecting falls in the older adult with eye diseases.

OBJECTIVES: Falls are the leading cause of injury-related hospitalization in older adult, presenting a significant public health concern. To examine the specific eye diseases for risk factors of falls in the older adult. METHODS: A total of 775 older adults admitted to tertiary care hospitals were divided into a fall or non-fall group based on a questionnaire. Logistic regression analysis was used to identify factors associated with falls. RESULTS: With 208 falls, 775 participants were recruited. The major associated factors of falls were older age (Odds ratios [OR]: 1.05), female (OR: 1.91), cardiovascular diseases (OR: 1.65), more outdoor activities (OR: 2.81), cataract (OR: 1.65), glaucoma (OR: 1.63), diabetic retinopathy (OR: 2.72). CONCLUSIONS: Our study demonstrates that cataract, glaucoma, and diabetic retinopathy in the older adult with eye diseases are independent risk factors of falls, which may shed light on the prevention of falls in the older adult with eye diseases.

Identification of retinal thickness and blood flow in age-related macular degeneration with reticular pseudodrusen.

AIM: To investigate thickness characteristics and vascular plexuses in retinas with reticular pseudodrusen (RPD) as an early detection strategy for age-related macular degeneration (AMD). METHODS: This retrospective study included 24 subjects (33 eyes) with RPD and 25 heathy control subjects (34 eyes). The superficial capillary plexus (SCP) and the deep capillary plexus (DCP) of the retinal posterior poles were investigated with optical coherence tomography angiography (OCTA). Retinal thicknesses and vessel densities were analyzed statistically. RESULTS: The general retinal thicknesses of RPD eyes were significantly decreased (95%CI -14.080, -0.655; P=0.032). The vessel densities of DCP in RPD eyes were significantly increased in the global (95%CI 1.067, 7.312; P=0.027), parafoveal (95%CI 0.417, 5.241; P=0.022), and perifoveal (95%CI 0.181, 6.842; P=0.039) quadrants. However, the vessel densities of the SCP were rarely increased in the eyes with RPD. CONCLUSION: The thinning of retinas in the RPD group suggests a reduction in the number of cells. Additionally, the increased vessel density of the DCP in retinas with RPD indicates a greater demand for blood supply, possibly due to the hypoxia induced RPD compensation caused by RPD in the outer retina. This study highlights the pathological risks associated with RPD and emphasizes the importance of early intervention to retard the progression of AMD.

Systemic Risk Factors for Vitreous Hemorrhage Secondary to Polypoidal Choroidal Vasculopathy.

INTRODUCTION: It remains unclear whether systemic factors are associated with an increased risk of vitreous hemorrhage (VH) secondary to polypoidal choroidal vasculopathy (PCV), and there is no method to predict the possibility of VH occurrence in patients with PCV. This study aimed to investigate and visualize systemic risk factors for VH in patients with PCV. METHODS: Data on the sex, age, history of systematic diseases, best-corrected visual acuity, intraocular pressure, and laboratory data of patients with PCV were collected from the medical record system. Univariate and multivariate binary logistic regression analyses were applied to investigate independent risk factors for VH in patients with PCV. Receiver operating characteristic analysis and nomograms were used to visualize the independent risk factors. RESULTS: The patient population comprised 115 patients with VH secondary to PCV and 181 patients with PCV without VH. Binary logistic regression analyses showed that higher white blood cell count [WBC; odds ratios (OR) 1.247], higher aspartate aminotransferase/alanine aminotransferase ratio (AST/ALT; OR 2.339), and longer activated partial thromboplastin time (APTT; OR 1.196) were independent risk factors of VH in patients with PCV. Integrated application of APTT, AST/ALT, and WBC as markers showed the best performance for distinguishing patients with VH, with an area under the curve of 0.723. The nomogram was created for doctors to calculate the possibility of VH in a patient with PCV. CONCLUSIONS: Higher WBC, higher AST/ALT, and longer APTT are independent serum risk factors of VH secondary to PCV, which may shed light on VH prevention in patients with PCV.

Efficacy and safety of 1565-nm nonablative fractional laser combined with mucopolysaccharide polysulfate cream for erythematous acne scars.

PURPOSE: To evaluate the efficacy and safety of 1565-nm nonablative fractional laser (NAFL) combined with mucopolysaccharide polysulfate (MPS) cream in the treatment of erythematous acne scars. METHODS: A total of 28 subjects with erythematous acne scars from June 2021 to April 2022 were enrolled. One side of each subject's face was randomly assigned to be treated with 1565-nm NAFL (at 2 sessions with four-week intervals) combined with MPS cream (twice daily) for 8 weeks, and the other side with 1565-nm NAFL combined with placebo cream. CBS® images and parameters, dermoscopic images and the quantitative data processed by ImageJ software, and quantitative global scarring grading system (GSS) score were obtained at baseline and after treatment. Subjects' satisfaction assessment was performed after treatment. Adverse events were recorded during treatment. RESULTS: In CBS® parameters, the red area, red area concentration, and smoothness were improved more significantly on the 1565-nm NAFL combined with MPS cream side than on the 1565-nm NAFL combined with placebo cream side after treatment (p = 0.015, p = 0.013, and p = 0.021). For dermoscopy, both scar area and scar redness achieved a significantly greater percentage of improvement on the side of 1565-nm NAFL combined with MPS cream than the side of 1565-nm NAFL combined with placebo cream after treatment (p = 0.005 and p = 0.041). The reduction of quantitative GSS score and Subjects' satisfaction assessment were similarly superior on the 1565-nm NAFL combined with MPS cream side. Temporary erythema was experienced by all subjects after each 1565-nm NAFL treatment. No subject reported intolerance or allergy to the cream during follow-up. CONCLUSIONS: The combined application of 1565-nm NAFL and MPS cream could be an effective and safe treatment for erythematous acne scars. ImageJ software enables quantitative evaluation of dermoscopic images of acne scars.

TACC diagnosed by transoesophageal endoscopic ultrasonography: A case report.

BACKGROUND: Primary adenoid cystic carcinoma in the trachea (TACC) is a rare tumour. Tracheal bronchoscopy is always chosen as a routine approach to obtain a pathological diagnosis, but it can be associated with an increased risk of asphyxia. CASE SUMMARY: We describe a case of TACC in a patient evaluated by chest computed tomography (CT) with three-dimensional reconstruction imaging and diagnosed by transoesophageal endoscopic ultrasonography. The pathological diagnosis confirmed tracheal adenoid cystic carcinoma. CONCLUSION: We highlight the importance of CT and provide a successful exploration of transoesophageal biopsy as a safe alternative approach.

The continuing discovery on the evidence for RNA editing in SARS-CoV-2.

Recent studies have presented strong evidence that C-to-U RNA editing is the driving force that fuels severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) evolution. The findings finally ended the long-term debate on the evolutionary driving force behind SARS-CoV-2 evolution. Here, we would first acknowledge the breakthroughs made by the recent works, such as using the global SARS-CoV-2 data to demonstrate the major mutation source of this virus. Meanwhile, we would raise a few concerns on the accuracy of their interpretation on C-to-U RNA editing. By re-analysing the SARS-CoV-2 population data, we found that the editing frequency on C-to-U sites did not perfectly correlate with the binding motif of the editing enzyme APOBEC, suggesting that there might be false-positive sites among the C-to-U mutations or the original data did not fully represent the novel mutation rate. We hope our work could help people understand the molecular basis underlying SARS-CoV-2 mutation and also be useful to guide future studies on SARS-CoV-2 evolution.

Combination therapy with BMSCs­exosomes and porous tantalum for the repair of femur supracondylar defects.

In the field of orthopedics, defects in large bones have proven challenging to resolve. The aim of the present study was to address this problem through the combination of tantalum metal (pTa) with exosomes derived from bone marrow mesenchymal stem cells (BMSCs), which have the potential to enhance regeneration of full thickness femoral bone defects in rats. Cell culture results demonstrated that exosomes improved the proliferation and differentiation of BMSCs. Following establishment of a supracondylar femoral bone defect, exosomes and pTa were implanted into the defect area. Results demonstrated that pTa acts as a core scaffold for cell adhesion and exhibits good biocompatibility. Moreover, micro­CT scan results as well as histological examination demonstrated that pTa had a significant effect on osteogenesis, with the addition of exosomes further promoting bone tissue regeneration and repair. In conclusion, this novel composite scaffold can effectively promote bone regeneration in large bone defect areas, providing a new approach for the treatment of large bone defects.

Treatment of Acetabular Bone Defect in Revision of Total Hip Arthroplasty Using 3D Printed Tantalum Acetabular Augment.

OBJECTIVE: The treatment of acetabular defects is one of the most difficult challenges of revision of total hip arthroplasty (RTHA), and tantalum is regarded as a promising bone substitute material. This study aims to investigate the effectiveness of 3D printed acetabular augment used in RTHA for the treatment of acetabular bone defect. METHODS: A retrospective analysis of the clinical data of seven patients who had undergone RTHA was carried out using 3D printed acetabular augment from January 2017 to December 2018. The CT data of the patients were exported to Mimics 21.0 software (Materialise, Leuven, Belgium), and the acetabular bone defect augment were designed, printed and then implanted during operation. The postoperative Harris score, visual analogue scale (VAS) score and prosthesis position were observed to evaluate the clinical outcome. A I-test was used for preoperative and postoperative comparison of the paired-design dataset. RESULTS: A firm attachment of the bone augment to the acetabulum during operation without any complications was found during the follow-up time 2.8-4.3 years. The VAS score of all patients was found 6.9 ± 1.4 before operation and was 0.7 ± 0.7 at the last follow-up (P ≤ 0.001), and the Harris hip scores, were 31.9 ± 10.3 and 73.3 ± 12.8 before operation, and at the last follow-up (P ≤ 0.001), respectively. Moreover, no loosening sign between the bone defect augment and the acetabulum was observed during the entire implantation period. CONCLUSION: 3D printed acetabular augment is effective in reconstructing the acetabulum following an acetabular bone defect revision, which enhances the hip joint function and eventually makes a satisfactory stable prosthetic.

Clinical Outcomes of Cardiac Shockwave Therapy in Severe Coronary Artery Disease Patients after Coronary Artery Bypass Grafting.

Cardiac shockwave therapy (CSWT) is a noninvasive treatment for patients with refractory angina or myocardial ischemia. This study aims to evaluate the potential beneficial effect and safety of CSWT in patients with severe coronary artery disease (CAD) who have undergone coronary artery bypass grafting (CABG).This was a single-arm prospective cohort study. A total of 30 patients with severe CAD who were not suitable for coronary revascularization and who had undergone CABG were enrolled. All patients received CSWT for nine sessions. Evaluation was performed before and after CSWT, including the Canadian Cardiovascular Society (CCS) classification, New York Heart Association (NYHA) classification, 6-minute walk test (6MWT), Seattle Angina Questionnaire (SAQ) score, nitroglycerin dosage, echocardiography, myocardial perfusion imaging (MPI), and safety parameters. All patients were followed up at both 1 month and 9 months after CSWT.After treatment, CSWT significantly improved CCS classification (P < 0.05), NYHA classification (P < 0.05), nitroglycerin dosage (P < 0.001), and 6MWT (P < 0.05) at 1 month and 9 months after CSWT. SAQ score (P < 0.05) and left ventricular ejection fraction (LVEF; P = 0.037) by echocardiography significantly improved at 1 month after CSWT. Significant decreases in summed stress score (SSS), summed difference score (SDS), ischemic area stress, and ischemic area difference by MPI were observed at 1 month and 9 months after CSWT (P < 0.01). There were no changes in safety parameters before and after CSWT.CSWT may have a beneficial effect on improving myocardial perfusion, clinical symptoms, exertional capacity, and quality of life and is a safe alternative treatment for patients with severe CAD who have undergone CABG.

Evidence Supporting That C-to-U RNA Editing Is the Major Force That Drives SARS-CoV-2 Evolution.

Mutations of DNA organisms are introduced by replication errors. However, SARS-CoV-2, as an RNA virus, is additionally subjected to rampant RNA editing by hosts. Both resources contributed to SARS-CoV-2 mutation and evolution, but the relative prevalence of the two origins is unknown. We performed comparative genomic analyses at intra-species (world-wide SARS-CoV-2 strains) and inter-species (SARS-CoV-2 and RaTG13 divergence) levels. We made prior predictions of the proportion of each mutation type (nucleotide substitution) under different scenarios and compared the observed versus the expected. C-to-T alteration, representing C-to-U editing, is far more abundant that all other mutation types. Derived allele frequency (DAF) as well as novel mutation rate of C-to-T are the highest in SARS-CoV-2 population, and C-T substitution dominates the divergence sites between SARS-CoV-2 and RaTG13. This is compelling evidence suggesting that C-to-U RNA editing is the major source of SARS-CoV-2 mutation. While replication errors serve as a baseline of novel mutation rate, the C-to-U editing has elevated the mutation rate for orders of magnitudes and accelerates the evolution of the virus.

A novel biomimetic trabecular bone metal plate for bone repair and osseointegration.

Fracture is one of the most common traumatic diseases in clinical practice, and metal plates have always been the first choice for fracture treatment because of their high strength. However, the bone plates have high elastic modulus and do not match the biomechanics of human bone, which adversely affects callus formation and fracture healing. Moreover, the complex microenvironment in the human body can induce corrosion of metallic materials and release toxic ions, which reduces the biocompatibility of the bone plate, and may necessitate surgical removal of the implant. In this study, tantalum (Ta) was deposited on porous silicon carbide (SiC) scaffolds by chemical vapor deposition technology to prepare a novel porous tantalum (pTa) trabecular bone metal plate. The function of the novel bone plate was evaluated by implantation in an animal fracture model. The results showed that the novel bone plate was effective in fracture fixation, without breakage. Both X-ray and microcomputed tomography analysis showed indirect healing by both pTa trabecular bone metal plates and titanium (Ti) plates; however, elastic fixation and obvious callus formation were observed after fixation with pTa trabecular bone metal plates, indicating better bone repair. Histology showed that pTa promoted the formation of new bone and integrated well with the host bone. Therefore, this novel pTa trabecular bone metal plate has good prospects for application in treating fractures.

Development and validation of a deep learning system to classify aetiology and predict anatomical outcomes of macular hole.

AIMS: To develop a deep learning (DL) model for automatic classification of macular hole (MH) aetiology (idiopathic or secondary), and a multimodal deep fusion network (MDFN) model for reliable prediction of MH status (closed or open) at 1 month after vitrectomy and internal limiting membrane peeling (VILMP). METHODS: In this multicentre retrospective cohort study, a total of 330 MH eyes with 1082 optical coherence tomography (OCT) images and 3300 clinical data enrolled from four ophthalmic centres were used to train, validate and externally test the DL and MDFN models. 266 eyes from three centres were randomly split by eye-level into a training set (80%) and a validation set (20%). In the external testing dataset, 64 eyes were included from the remaining centre. All eyes underwent macular OCT scanning at baseline and 1 month after VILMP. The area under the receiver operated characteristic curve (AUC), accuracy, specificity and sensitivity were used to evaluate the performance of the models. RESULTS: In the external testing set, the AUC, accuracy, specificity and sensitivity of the MH aetiology classification model were 0.965, 0.950, 0.870 and 0.938, respectively; the AUC, accuracy, specificity and sensitivity of the postoperative MH status prediction model were 0.904, 0.825, 0.977 and 0.766, respectively; the AUC, accuracy, specificity and sensitivity of the postoperative idiopathic MH status prediction model were 0.947, 0.875, 0.815 and 0.979, respectively. CONCLUSION: Our DL-based models can accurately classify the MH aetiology and predict the MH status after VILMP. These models would help ophthalmologists in diagnosis and surgical planning of MH.

Effects of angiotensin II combined with asparaginase and dexamethasone on the femoral head in mice: A model of steroid-induced femoral head osteonecrosis.

Background: To study the pathogenesis of steroid-induced femoral head osteonecrosis, an ideal animal model is very important. As experimental animals, mice are beneficial for studying the pathogenesis of disease. However, there are currently few mouse models of steroid-induced femoral head osteonecrosis, and there are many questions that require further exploration and research. Purposes: The purpose of this study was to establish a new model of osteonecrosis in mice using angiotensin II (Ang II) combined with asparaginase (ASP) and dexamethasone (DEX) and to study the effects of this drug combination on femoral head osteonecrosis in mice. Methods: Male BALB/c mice (n = 60) were randomly divided into three groups. Group A (normal control, NC) was treated with physiological saline and given a normal diet. Group B (DEX + ASP, DA) was given free access to food and water (containing 2 mg/L DEX) and subjected to intraperitoneal injection of ASP (1200 IU/kg twice/week for 8 weeks). Group C (DEX + ASP + Ang II, DAA) was treated the same as group B, it was also given free access to food and water (containing 2 mg/L DEX) and subjected to intraperitoneal injection of ASP (1200 IU/kg twice/week for 8 weeks), but in the 4th and 8th weeks, subcutaneous implantation of a capsule osmotic pump (0.28 mg/kg/day Ang II) was performed. The mice were sacrificed in the 4th and 8th weeks, and the model success rate, mouse mortality rate, body weight, blood lipids, coagulation factors, histopathology, and number of local vessels in the femoral head were evaluated. Results: DAA increased the model success rate [4th week, 30% (DA) vs. 40% (DAA) vs. 0% (NC); 8th week, 40% (DA) vs. 70% (DAA) vs. 0% (NC)]. There was no significant difference in mortality rate between the groups [4th week, 0% (DA) vs. 0% (DAA) vs. 0% (NC); 8th week, 5% (DA) vs. 10% (DAA) vs. 0% (NC)]. DAA affected mouse body weight and significantly affected blood lipids and blood coagulation factors. DAA reduces the number of blood vessels in the femoral head and destroys the local blood supply. Conclusion: Angiotensin II combined with asparaginase and dexamethasone can obviously promote the necrosis of femoral head and provide a new idea for the model and treatment of osteonecrosis.