BACKGROUND:The most common complication of traumatic femoral neck fractures after internal fixation is femoral head necrosis.Currently,many studies have reported on the risk factors that affect the occurrence and development of postoperative femoral head necrosis,but there is still a lack of tools to predict the risk of femoral head necrosis after internal fixation of femoral neck fractures.OBJECTIVE:To develop a predictive model that estimates the risk of femoral head necrosis shortly after patients with femoral neck fractures receive cannulated screw internal fixation.METHODS:A retrospective analysis reviewed clinical records of 172 patients who underwent cannulated screw internal fixation for femoral neck fractures at Department of Orthopedics of Mianyang Central Hospital from January 2013 to June 2023.Patients were categorized into two groups based on the presence or absence of femoral head necrosis within one year post-operation:the necrosis group and the non-necrosis group.Univariate analysis,Lasso regression,and multivariate Logistic regression techniques were employed to identify the determinants of femoral head necrosis.A nomogram prediction model was constructed using R language's"rms"package,version 4.0.The receiver operating characteristic curve was used to evaluate the discriminatory ability of the model.The Hosmer-Lemeshow test was used to evaluate the goodness of fit of the model,and the decision curve analysis was used to determine its clinical application benefits.Internal validation of the study was conducted using the Bootstrap method,involving 1 000 repeated samplings.To delve deeper into the primary factors influencing femoral head necrosis post-internal fixation of the femoral neck,this paper employed the SHAP method for data set analysis.RESULTS AND CONCLUSION:(1)The risk factors leading to femoral head necrosis in the short term after cannulated screw fixation of femoral neck fractures include:smoking,diabetes,Garden classification,fracture line location,reduction quality,age,and operation time.(2)The prediction model demonstrated robust performance,evidenced by an area under the curve of 0.940(95％Confidence Interval:0.903 to 0.977),indicating a high level of prediction accuracy.The model achieved a sensitivity of 90.2％and a specificity of 87.6％,indicating that its diagnostic performance was stable.The Hosmer-Lemeshow goodness-of-fit test yielded a chi-square value of 6.593 with a P-value of 0.581,confirming that the model's predictions closely align with the observed outcomes.(3)The calibration curve of the model also performed well,and its overall trend was very close to the ideal curve,further proving the high accuracy of the model.(4)The internal validation was carried out by the Bootstrap method with 1 000 repeated samplings,and the area under the curve of the model internal validation was still as high as 0.939,proving that the model had good stability.(5)Through the decision curve,it is found that within the probability threshold range of 1％to 92％,the model can obtain the maximum net benefit value.(6)The SHAP analysis results show that among the risk factors analyzed in this study,the location of the fracture line serves as the most significant predictor of femoral head necrosis following internal fixation with cannulated screws in femoral neck fractures,and subcapital fractures are extremely prone to femoral head necrosis after surgery.(7)It is concluded that the validated prediction model demonstrates strong discriminative power and reliability,offering practical clinical utility.It serves as a useful reference tool for short-term risk assessment of femoral head necrosis following internal fixation of femoral neck fractures.

BACKGROUND:Studies have shown that there is a close relationship between pyroptosis,inflammatory factors and osteoporosis.OBJECTIVE:To review the effects of pyroptosis and inflammatory factors on the pathogenesis of osteoporosis from the perspectives of osteogenic differentiation and osteoclastic differentiation,based on an overview of pyroptosis in relation to the interaction of relevant inflammatory factors.METHODS:The first author used the computer to search the literature published by each database until 2024,and searched CNKI,WanFang,VIP and PubMed databases with the search terms of"pyroptosis,inflammatory factors,osteoporosis,osteoblast,osteoclast,bone metabolism,signaling pathway,review"in Chinese and English.A total of 79 papers were finally included according to the inclusion criteria.RESULTS AND CONCLUSION:The progression of osteoporosis is closely related to inflammation,in which pyroptosis plays a key role.Immune cells induce pyroptosis through apoptosis pathway,promote the secretion of inflammatory factors such as interleukin-18,interleukin-1β and NLRP3,build an inflammatory immune microenvironment,and regulate bone metabolism through complex signaling pathways,resulting in enhanced bone absorption and reduced bone formation,thereby leading to osteoporosis.Previous studies have shown that inhibiting pyroptosis is anti-inflammatory and slows the progression of osteoporosis,and it has been shown to improve inflammatory bone loss in vitro and in animal models.At present,research on pyroptosis and osteoporosis is limited.On the one hand,the exact mechanism of osteoporosis and the pathogenesis of pyroptosis are unknown,and the specific pathways and regulatory mechanisms remain to be understood.On the other hand,therapeutic strategies targeting pyroptosis are still theoretical,not clinically proven,and drug side effects are unknown.In the future,the research focus is to further explore the pathogenesis,especially the mechanism of pyroptosis,identify potential therapeutic targets,further study the pyroptosis signaling pathway and Gasdermin protein,and develop new drugs to improve the therapeutic effect in patients with osteoporosis.

OBJECTIVE:Patients with osteoporotic vertebral compression fractures still have residual back pain after vertebral augmentation.The current research is characterized by limited sample size,complex confounding factors,and inconsistent research results.To gain a deeper understanding of this phenomenon,the aim of this study was to identify and evaluate the risk factors for residual back pain after surgery through a systematic review and meta-analysis.METHODS:A comprehensive search was conducted in CNKI,VIP,WanFang,CBMdisc,PubMed,The Cochrane Library,Embase,and Web of Science for case-control studies on residual back pain after vertebral body augmentation for osteoporotic vertebral compression fractures from database inception to July 2024.The search terms were a combination of subject terms and free terms.The basic information,patient characteristics,surgical-related indicators,and risk factors for surgical back pain of the included studies were extracted.After evaluating the bias risk of all included studies,a meta-analysis was conducted using Stata 14.0 software on the relevant indicators.RESULTS:(1)21 case-control studies with a total of 8 043 patients were included.Among them,965 patients developed back pain.The quality score of all 21 studies was ≥7.(2)The meta-analysis results showed that age(WMD=0.98,95％CI:0.40-1.56,P=0.010),bone mineral density(WMD=-0.28,95％CI:-0.34 to-0.21,P=0.000),the number of vertebral fractures(OR=3.50,95％CI:2.65-4.62,P=0.000),thoracolumbar fracture index(OR=3.65,95％CI:2.61-5.11,P=0.000),cement volume(OR=6.89,95％CI:2.62-18.17,P=0.000),and cement distribution(OR=2.38,95％CI:1.93-2.93,P=0.000)were risk factors for the development of back pain after vertebral body augmentation in patients with osteoporotic vertebral compression fractures.CONCLUSION:Current evidence indicates that age,bone mineral density,the number of vertebral fractures,thoracolumbar fracture index,bone cement injection volume,and the distribution of bone cement are risk factors for low back pain.Specifically,bone mineral density,the number of vertebral fractures,thoracolumbar fracture index,and non-uniform distribution of bone cement are identified as independent risk factors for low back pain.Patients exhibiting these high-risk factors require vigilant monitoring and prompt intervention to mitigate the occurrence of clinical low back pain,thereby enhancing patient outcomes and quality of life.

BACKGROUND:Developing a material that promotes alveolar bone regeneration and has good properties is of great significance for the treatment of alveolar bone defects.OBJECTIVE:To summarize the research on alveolar bone defect regeneration and repair in the past 5 years,classify and introduce new materials and drugs,so as to grasp the latest progress in related fields.METHODS:"Alveolar bone,alveolar bone defect,alveolar bone regeneration,mechanism,biomaterials,nanoscaffolds,hydrogels,medications,anti-inflammatory drugs,simvastatin,metformin,traditional Chinese medicine,growth factor,stem cell"were used as search terms in Chinese and English for literature retrieval in CNKI and PubMed,respectively.A total of 117 articles were finally obtained for review and analysis.RESULTS AND CONCLUSION:The application of biomaterials provides a scaffold structure for alveolar bone regeneration and can also be used as a bone substitute to repair bone defects.Topical and systemic applications of Western and Chinese medicines can control inflammation and promote bone regeneration.Materials loaded with various growth factors have the effect of osteogenesis and can promote the repair of alveolar bone defects.In stem cell tissue engineering,the seed cells are osteogenic and fibrogenic,which can differentiate into osteoblasts to generate new bone.In recent years,research has been keen on the combination of the above to develop new,biocompatible,and slow-release drugs or materials to promote the regeneration and repair of alveolar bone defects.

BACKGROUND:Bone tissue loss caused by tumors and trauma can have an adverse effect on postoperative rehabilitation.Therefore,scaffold materials are usually implanted during treatment.However,the existing implant materials are relatively simple and lack antibacterial properties.Early implantation may lead to iatrogenic autoinfection and have an adverse effect on osteogenesis.OBJECTIVE:To construct a KR-12-a5 polypeptide-nanohydroxyapatite-small intestinal submucosa composite scaffold and evaluate its feasibility as a material for promoting bone defect repair.METHODS:The small intestinal submucosa scaffold and the small intestinal submucosa scaffold containing 25,50,and 100 mg/mL nanohydroxyapatite(referred to as nHA-SIS scaffold)were prepared by 1-ethyl-3-(3-dimethylaminopropyl)carbodiimide hydrochloride/N-hydroxysuccinimide cross-linking method.The appropriate scaffold was screened for subsequent experiments by mechanical property testing.The antibacterial properties of KR-12-a5 polypeptide solution against Staphylococcus aureus,Streptococcus gordonii,and Fusobacterium nucleatum were detected.The nHA-SIS scaffolds were immersed in 250,500,and 1 000 μg/mL KR-12-a5 peptide solutions for 24 hours,and then freeze-dried to obtain peptide-loaded nanohydroxyapatite-porcine small intestinal submucosa composite scaffolds(denoted as P-nHA-SIS scaffolds).The sustained-release properties of the three groups of scaffolds were characterized.The nHA-SIS scaffolds and the three groups of P-nHA-SIS scaffolds were co-cultured with Staphylococcus aureus,Streptococcus gordonii,and Fusobacterium nucleatum for 24 hours or 48 hours.The scaffolds with strong antibacterial ability were screened by live and dead bacteria staining and scanning electron microscopy for subsequent experiments.The degradation properties and water absorption rates of the uncross-linked small intestinal submucosa scaffolds,cross-linked small intestinal submucosa scaffolds,nHA-SIS scaffolds,and P-nHA-SIS scaffolds were characterized.The extracts of cross-linked small intestinal submucosal scaffolds,nHA-SIS scaffolds,and P-nHA-SIS scaffolds were co-cultured with MC3T3-E1 cells.CCK-8 assay and live-dead cell staining were performed.The effects of the extracts of the three scaffolds on the migration of MC3T3-E1 cells were detected by Transwell chamber assay.RESULTS AND CONCLUSION:(1)The elastic modulus and compressive strength of 25,50,and 100 mg/mL nHA-SIS scaffolds were higher than those of small intestinal submucosal scaffolds(P＜0.05),among which the elastic modulus and compressive strength of 25 mg/mL nHA-SIS scaffolds were the highest,and this group of scaffolds were selected for subsequent experiments to load peptides.(2)KR-12-a5 peptide had strong antibacterial activity against common bacteria in bone defects(Staphylococcus aureus,Streptococcus gordonii,and Fusobacterium nucleatum).The three groups of P-nHA-SIS scaffolds all had sustained release properties.With the increase of peptide mass concentration,the antibacterial property of P-nHA-SIS scaffold was enhanced.Among them,the P-nHA-SIS scaffold loaded with 500 μg/mL peptide had achieved a satisfactory antibacterial effect,and this group of scaffolds would be selected in the future.(3)The degradation rate of the three groups of cross-linked scaffolds was lower than that of the uncross-linked scaffolds,and the water absorption rate was greater than that of the uncross-linked scaffolds.P-nHA-SIS scaffolds could promote the proliferation and migration of MC3T3-E1 cells without affecting the activity of MC3T3-E1 cells.(4)The results show that P-nHA-SIS scaffolds have strong antibacterial properties and the ability to promote the proliferation and migration of MC3T3-E1 cells,and are expected to be used in bone defect repair.

BACKGROUND:Mineralized collagen is the fundamental unit of bone structure and function and a major component of the extracellular matrix.Biomimetic methods have been developed to fabricate mineralized collagen with a natural bone nanostructure.Currently,mineralized collagen has been approved by regulatory authorities and applied clinically,playing a positive role in bone defect repair.OBJECTIVE:To present the integration strategies of bioactive factors with mineralized collagen,summarize schemes to enhance the osteogenic potential of mineralized collagen,emphasize the multifunctional coordination applications of mineralized collagen,and finally discuss current research focuses and future trends.METHODS:The authors searched for relevant literature in databases such as PubMed,Web of Science,Medline,WanFang,and CNKI,from 2009 to 2023,using keywords"mineralized collagen,biomimetic,functionalization,bioactive factors,osteogenesis,multi-functional coordination,bone tissue repair"in English and"mineralized collagen,biomimetic,functionalization"in Chinese.Out of 375 initially identified articles,57 were included for review after screening.RESULTS AND CONCLUSION:(1)Mineralized collagen,with its porous structure and large surface area,containing nano-hydroxyapatite,makes it an effective carrier for cells,various growth factors,and drugs.(2)Single or multiple bioactive factors can be efficiently and orderly released through different loading methods or combinations,achieving the multifunctionalization of mineralized collagen.The impact of physicochemical conditions on the bioactivity of factors and their effects on the degradability,hydroxylapatite crystal morphology,nanostructure,and content of mineralized collagen should be considered.Moreover,calcium ions in mineralized collagen can be substituted with various inorganic non-metal ions,enhancing its osteogenic,angiogenic,immunomodulatory,and anti-infective properties.(3)Ultimately,during in situ bone regeneration,functionalized mineralized collagen serves as a scaffold material,providing structural support for bone defects,and as a drug delivery system,continuously delivering various bioactive factors locally,playing roles in anti-infection,immunomodulation,promoting angiogenesis and osteogenesis,and repairing various complex bone defects.

BACKGROUND:With the development of oral implantology,implant restoration has gradually become the first choice of restoration after missing teeth,and bone augmentation procedures have led to the expansion of implant indications and the improvement of the success rate of implant restoration.However,the long-term stability of bone height,width and volume after bone augmentation surgery has been one of the clinical difficulties for oral implantologists.OBJECTIVE:To measure and analyze the bone width,height,and volume of different sites in the bone augmentation area at different time points using cone-beam CT and an automatic image alignment program.METHODS:Seventeen patients with severe bone defects in the upper anterior region who underwent Onlay bone block grafting in the external oblique region were recruited from the Department of Stomatology,Zhejiang Tongde Hospital.There were 10 males and 7 females,with a mean age of(45.88±12.47)years.The cone-beam CT scans of the patients' Onlay bone grafts were taken at five time points:preoperatively,immediately postoperatively,6 months postoperatively,immediately post implantation,and 6 months post implantation,and then were statistically analyzed for alveolar bone volume,width,and height in the bone augmentation area,as well as for the difference in the alveolar bone volume of the bone incremental area between patients of different sexes and age.RESULTS AND CONCLUSION:(1)The alveolar bone volume in the bone augmentation area was higher immediately and 6 months after bone grafting than before bone grafting(P＜0.05)as well as was higher immediately after bone grafting than 6 months after bone grafting(P＜0.05).The alveolar bone height in the bone augmentation area was higher immediately and 6 months after bone grafting than before bone grafting(P＜0.05).The horizontal width of the alveolar bone at various sites in the bone augmentation area immediately and 6 months after bone grafting was higher than that before bone grafting(P＜0.05).(2)There was no significant difference in the volume of bone graft resorption at various sites in the bone augmentation area between males and females immediately and 6 months after bone grafting(P＞0.05).Pearson correlation analysis showed a positive correlation between age and the change in bone augmentation area volume immediately and 6 months after bone grafting,but the difference was not statistically significant(P＞0.05).(3)Twenty-five dental implants with completed implant restorations functioned normally,and the survival rate of the implants was 100％.To conclude,Onlay bone graft implant restoration in the upper anterior region can significantly improve insufficient bone with favorable outcomes.However,there is some amount of bone resorption in the bone augmentation area at 6 months after Onlay bone grafting and it is necessary to open up the second surgical area.Clinicians should consider different bone augmentation procedures in accordance with the specific circumstances.

BACKGROUND:Cellular senescence,which triggers the aging process of physiological decline in the body,is closely related to osteoporosis.With the development of aging research,significant progress has been made in the study of targeted clearance of senescent cells.Accordingly,senolytic cell therapy for osteoporosis based on this has attracted increasing attention.Current research on the association between aging and osteoporosis shows the characteristic of multidisciplinary intersection.However,existing reviews are mostly based on a single database(such as PubMed)and lack a systematic comparative analysis of Chinese and English literature.Therefore,it is of great academic value to integrate resources from multiple databases and systematically reveal the research status and hot trends of aging in the field of osteoporosis research.OBJECTIVE:To summarize the development,current status,hotspots,and future trends of research on aging in the field of osteoporosis over the past 20 years,so as to provide references for future related research.METHODS:We searched for research literature on the correlation between aging and osteoporosis in CNKI,WanFang,VIP and Web of Science Core Database.The search time span was from August 1,2004 to September 24,2024.Then,we used NoteExpress 4.0 for data cleaning and CiteSpace 6.3R1(Advanced)and Excel(2024)for literature analysis.RESULTS AND CONCLUSION:Since 2004,research on the correlation between aging and osteoporosis has shown a significant growth trend.Bibliometric analysis shows that(as of September 2024),and 1 275 English documents and 151 Chinese documents have been published,with the highest number of publications in China and the United States.In terms of publishing institutions,the Mayo Clinic ranked first,followed by Shanghai Jiao Tong University and the University of California system.As for core authors,Sundeep Khosla and Joshua Nicholas Farr were the authors with the most publications and citations,while Pei Lingpeng and Hui Bodi were the most worthy of attention in Chinese literature.After the keywords"aging"and"osteoporosis"and their synonyms were excluded,it was found that cellular senescence,senescence-associated secretory phenotype,signaling pathways,and targeted senolytic cell clearance therapy haven been the current research hotspots and theoretical frontiers.

BACKGROUND:Chimeric antigen receptor T cell therapy is a cutting-edge approach for the treatment of B cell hematological malignancies.These cells efficiently and specifically recognize and kill tumor cells,unrestricted by major histocompatibility complex limitations.OBJECTIVE:To elucidate the structure,developmental history,and marketed progress of chimeric antigen receptor T cells,summarize their long-term efficacy in B cell hematological malignancies treatments,and discuss associated toxicities,recurrence,and mitigation strategies.Additionally,it reviews the advancement of potential targets in B cell hematological malignancies treatments.METHODS:Searches were conducted in PubMed,CNKI,and WanFang databases using the terms"CAR-T,B cell hematological malignancies,toxic side effects,immunotherapy"in Chinese and English,focusing on articles regarding chimeric antigen receptor T cell targets in B-cell malignant tumor treatments.RESULTS AND CONCLUSION:(1)The U.S.Food and Drug Administration and National Medical Products Administration have approved 11 chimeric antigen receptor T cell products,primarily targeting CD19 and B cell maturation antigen targets in B cell hematological malignancies.(2)Long-term follow-up data indicate that chimeric antigen receptor T cell therapy provides a high remission rate and enduring responses in B cell hematological malignancies patients,albeit with recurrence issues due to antigen loss or downregulation.(3)Chimeric antigen receptor T cell therapy is associated with significant toxicities,a high recurrence rate,and drug resistance,constraining its broad application.(4)Future research should concentrate on developing new targets,combined therapies,and strategies to enhance chimeric antigen receptor T cell persistence and antitumor activity.

BACKGROUND:Abutment screw loosening is one of the most common mechanical complications in implant restoration.Mechanical wear,as a potential cause of thread loosening,warrants attention due to its impact on mechanical performance and long-term stability.However,studies on the mechanical effects of thread wear in abutment screws remain limited,and no definitive conclusions have been reached.OBJECTIVE:To investigate the effect of different degrees of mechanical wear on the spatial stress distribution of the Morse taper connection implant system,with a view to providing a theoretical basis for the clinical assessment of the long-term stability of dental implants.METHODS:Three-dimensional finite element models of Morse taper implants with central screw thread wear levels of 0,0.1,1,10,and 100 μm were established using SolidWorks software,and simulation analysis with Ansys Workbench software was performed.The implant models were inserted into artificial bone blocks(simulating type Ⅱ bone,with a cortical bone thickness of 2 mm on the outer layer and cancellous bone inside).An alternating load of 300 N in the buccolingual direction was applied at the centroid of the abutment(forming an angle of 30° with the long axis of the implant).The von Mises stress,principal stress,displacement,and fatigue life of the abutment,central screw,implant,and bone tissue in the five groups of models were analyzed.RESULTS AND CONCLUSION:(1)As the degree of mechanical wear on the central screw thread increased,the von Mises stress,principal stress,and strain in the implant and abutment also increased.The stress in the model was concentrated at the top of the implant,at the shoulder level of the implant,at the neck of the abutment,and at the bottom edge of the abutment.(2)Under moderate wear conditions(≥ 10 μm),the fatigue life of the implant system decreased by 30％,and the maximum von Mises stress of the central screw decreased by 37％,with the stress still primarily concentrated at the transition area between the head and the body of the central screw.(3)Under significant wear conditions(≥ 100 μm),the von Mises stress of the central screw decreased by 98％,with the stress concentrated at the screw head,and the fatigue life of the implant system decreased by 63％.Therefore,when the wear level of the central screw thread reaches ≥ 10 μm,the risk of screw loosening is significantly increased,and the fatigue life of the implant system is markedly reduced,warranting clinical attention.