Objective:To explore the effect of the defect area and volume of intra-articular impacted fragments (IAIF) on the contact stress of the ankle joint surface.Methods:A 23-year-old male volunteer, 168 cm in height and 60 kg in weight, with no history of trauma or anatomic abnormality of the ankle, was selected. On the basis of a normal ankle finite-element model, IAIF-defect finite-element models were established. The first group consisted of IAIF-defect models with identical area but different volumes: on the distal tibial articular surface the defect area was 4 mm × 5 mm (20 mm 2), and the heights were 2 mm, 3 mm, 4 mm, 5 mm and 6 mm. The second group consisted of IAIF-defect models with identical defect volume but different areas. The defect volume was 90 mm 3, while the defect areas on the distal tibial articular surface were 2 mm×3 mm, 3 mm×3 mm, 3 mm×5 mm, 3 mm×6 mm, and 5 mm×6 mm, with corresponding heights of 15 mm, 10 mm, 6 mm, 5 mm, and 3 mm. Under a 600 N vertical load the contact stress of the ankle joint was calculated, and the finite-element data were recorded and analyzed. Pearson correlation analysis was used to analyze, separately for the two groups, the correlation between IAIF defect and the maximum contact stress (MCS) of the distal tibial articular surface, and simple linear regression analysis was performed to obtain regression equations. Equivalence zero testing was used to verify the correlations and to compare their differences. Results:For IAIF defects with the same area but different volumes, including 4 mm×5 mm×2 mm, 4 mm×5 mm×3 mm, 4 mm×5 mm×4 mm, 4 mm×5 mm×5 mm, and 4 mm× 5 mm×6 mm, the corresponding maximum contact stress (MCS) on the distal tibial joint surface were 3.846 MPa, 3.839 MPa, 3.835 MPa, 3.833 MPa, and 3.831 MPa, respectively, with an average of 3.837 MPa. The mean ±1% range is from 3.799 MPa to 3.875 MPa. The correlation analysis showed that the IAIF defects with the same area but different volumes were negatively correlated with contact stress ( r=-0.956, P=0.011). The linear regression equation was MCS=-0.0002×VI+3.851, where VI denotes IAIF volume. Equivalence zero testing confirmed that all measured values lay within the predefined ±1 % margin, satisfying the equivalence null hypothesis. For IAIF defects of identical volume (90 mm 3) but varying articular surface areas—2 mm×3 mm, 3 mm×3 mm, 3 mm×5 mm, 3 mm×6 mm and 5 mm×6 mm—the corresponding MCS values were 2.147 MPa, 2.812 MPa, 3.622 MPa, 4.476 MPa and 6.186 MPa, respectively (mean 3.849 MPa; equivalence band 3.811-3.887 MPa at ±1% of the mean). Correlation analysis demonstrated a strong positive relationship between identical-volume varying-area IAIF defects and contact stress ( r=0.996, P<0.001). The linear regression equation was MCS=0.168×AI+1.236, where AI denotes IAIF area. Equivalence zero testing indicated that none of the measured values fell within the predefined ±1% margin, failing to satisfy the equivalence null hypothesis. Conclusion:In posterior ankle fractures, the volume change of IAIF defects has no clinical significance in relation to MCS, showing a small negative correlation. However, the area change of IAIF defects is clinically significant in relation to MCS, demonstrating a larger positive correlation.

BACKGROUND:The reduction of contact area,edge load,and stress increase of adjacent cartilage caused by knee cartilage defect are considered to easily cause degenerative changes in this tissue,which may develop into knee osteoarthritis.Growth factors are considered to be a treatment method to promote the healing of damaged cartilage and delay the progression of degenerative arthritis.OBJECTIVE:To analyze the hotspots and prospects of growth factor-promoted knee cartilage regeneration research by bibliometric methods.METHODS:The first author retrieved 321 articles related to growth factor-promoted knee cartilage regeneration research from the Web of Science core set database.VOSviewer 1.6.19 software was used to analyze the publication volume,country,institution,keyword,and literature citation status of the articles,and investigate the research hotspots.RESULTS AND CONCLUSION:(1)From 2000 to 2024,the annual number of publications in the field of growth factor-promoted knee cartilage regeneration showed an overall upward trend,with the highest number of publications in 2021.Harvard University in the United States published the most papers.(2)Keyword analysis showed that the frequency of keywords such as growth factor,cartilage,cartilage repair,platelet-rich plasma,and cartilage regeneration was high.In addition,the keyword co-occurrence network diagram showed that growth factor was closely related to keywords such as cartilage repair and cartilage regeneration,indicating that growth factor research plays an important role in the field of cartilage regeneration.(3)The results of literature citation analysis showed that the combination of platelet-rich plasma and muscle-derived stem cells may provide a new and effective treatment strategy for patients with osteoarthritis,which can deepen the understanding of cartilage repair mechanisms by promoting stem cell proliferation and cartilage formation.Fibroblast growth factor 2,fibroblast growth factor 18,and insulin growth factor 1 play a key role in cartilage repair and can promote chondrocyte proliferation and matrix synthesis.In particular,fibroblast growth factor 18 can promote the repair of damaged cartilage,thereby alleviating patients'pain and dysfunction,which deserves further in-depth study in the future.The latest research has developed a new Polyhedrin Delivery System(PODS)that can continuously release growth factors such as bone morphogenetic protein 2 and 7,significantly promoting chondrocyte proliferation and cartilage repair.This system provides a new perspective and potential therapy for the treatment of osteoarthritis.(4)Therefore,bone morphogenetic protein 2,7,insulin growth factor 1,and recombinant human fibroblast growth factor 18 are promising growth factor therapies for promoting cartilage regeneration.In the future,further in-depth research on the mechanism of action of growth factors,optimization of treatment strategies,and strengthening of long-term efficacy and safety evaluation are needed.

Objective:To explore the effect of the defect area and volume of intra-articular impacted fragments (IAIF) on the contact stress of the ankle joint surface.Methods:A 23-year-old male volunteer, 168 cm in height and 60 kg in weight, with no history of trauma or anatomic abnormality of the ankle, was selected. On the basis of a normal ankle finite-element model, IAIF-defect finite-element models were established. The first group consisted of IAIF-defect models with identical area but different volumes: on the distal tibial articular surface the defect area was 4 mm × 5 mm (20 mm 2), and the heights were 2 mm, 3 mm, 4 mm, 5 mm and 6 mm. The second group consisted of IAIF-defect models with identical defect volume but different areas. The defect volume was 90 mm 3, while the defect areas on the distal tibial articular surface were 2 mm×3 mm, 3 mm×3 mm, 3 mm×5 mm, 3 mm×6 mm, and 5 mm×6 mm, with corresponding heights of 15 mm, 10 mm, 6 mm, 5 mm, and 3 mm. Under a 600 N vertical load the contact stress of the ankle joint was calculated, and the finite-element data were recorded and analyzed. Pearson correlation analysis was used to analyze, separately for the two groups, the correlation between IAIF defect and the maximum contact stress (MCS) of the distal tibial articular surface, and simple linear regression analysis was performed to obtain regression equations. Equivalence zero testing was used to verify the correlations and to compare their differences. Results:For IAIF defects with the same area but different volumes, including 4 mm×5 mm×2 mm, 4 mm×5 mm×3 mm, 4 mm×5 mm×4 mm, 4 mm×5 mm×5 mm, and 4 mm× 5 mm×6 mm, the corresponding maximum contact stress (MCS) on the distal tibial joint surface were 3.846 MPa, 3.839 MPa, 3.835 MPa, 3.833 MPa, and 3.831 MPa, respectively, with an average of 3.837 MPa. The mean ±1% range is from 3.799 MPa to 3.875 MPa. The correlation analysis showed that the IAIF defects with the same area but different volumes were negatively correlated with contact stress ( r=-0.956, P=0.011). The linear regression equation was MCS=-0.0002×VI+3.851, where VI denotes IAIF volume. Equivalence zero testing confirmed that all measured values lay within the predefined ±1 % margin, satisfying the equivalence null hypothesis. For IAIF defects of identical volume (90 mm 3) but varying articular surface areas—2 mm×3 mm, 3 mm×3 mm, 3 mm×5 mm, 3 mm×6 mm and 5 mm×6 mm—the corresponding MCS values were 2.147 MPa, 2.812 MPa, 3.622 MPa, 4.476 MPa and 6.186 MPa, respectively (mean 3.849 MPa; equivalence band 3.811-3.887 MPa at ±1% of the mean). Correlation analysis demonstrated a strong positive relationship between identical-volume varying-area IAIF defects and contact stress ( r=0.996, P<0.001). The linear regression equation was MCS=0.168×AI+1.236, where AI denotes IAIF area. Equivalence zero testing indicated that none of the measured values fell within the predefined ±1% margin, failing to satisfy the equivalence null hypothesis. Conclusion:In posterior ankle fractures, the volume change of IAIF defects has no clinical significance in relation to MCS, showing a small negative correlation. However, the area change of IAIF defects is clinically significant in relation to MCS, demonstrating a larger positive correlation.

BACKGROUND:The reduction of contact area,edge load,and stress increase of adjacent cartilage caused by knee cartilage defect are considered to easily cause degenerative changes in this tissue,which may develop into knee osteoarthritis.Growth factors are considered to be a treatment method to promote the healing of damaged cartilage and delay the progression of degenerative arthritis.OBJECTIVE:To analyze the hotspots and prospects of growth factor-promoted knee cartilage regeneration research by bibliometric methods.METHODS:The first author retrieved 321 articles related to growth factor-promoted knee cartilage regeneration research from the Web of Science core set database.VOSviewer 1.6.19 software was used to analyze the publication volume,country,institution,keyword,and literature citation status of the articles,and investigate the research hotspots.RESULTS AND CONCLUSION:(1)From 2000 to 2024,the annual number of publications in the field of growth factor-promoted knee cartilage regeneration showed an overall upward trend,with the highest number of publications in 2021.Harvard University in the United States published the most papers.(2)Keyword analysis showed that the frequency of keywords such as growth factor,cartilage,cartilage repair,platelet-rich plasma,and cartilage regeneration was high.In addition,the keyword co-occurrence network diagram showed that growth factor was closely related to keywords such as cartilage repair and cartilage regeneration,indicating that growth factor research plays an important role in the field of cartilage regeneration.(3)The results of literature citation analysis showed that the combination of platelet-rich plasma and muscle-derived stem cells may provide a new and effective treatment strategy for patients with osteoarthritis,which can deepen the understanding of cartilage repair mechanisms by promoting stem cell proliferation and cartilage formation.Fibroblast growth factor 2,fibroblast growth factor 18,and insulin growth factor 1 play a key role in cartilage repair and can promote chondrocyte proliferation and matrix synthesis.In particular,fibroblast growth factor 18 can promote the repair of damaged cartilage,thereby alleviating patients'pain and dysfunction,which deserves further in-depth study in the future.The latest research has developed a new Polyhedrin Delivery System(PODS)that can continuously release growth factors such as bone morphogenetic protein 2 and 7,significantly promoting chondrocyte proliferation and cartilage repair.This system provides a new perspective and potential therapy for the treatment of osteoarthritis.(4)Therefore,bone morphogenetic protein 2,7,insulin growth factor 1,and recombinant human fibroblast growth factor 18 are promising growth factor therapies for promoting cartilage regeneration.In the future,further in-depth research on the mechanism of action of growth factors,optimization of treatment strategies,and strengthening of long-term efficacy and safety evaluation are needed.

Objective To evaluate the stability,safety and immune enhancement and anti-tumor effects of Wilms'tumor gene 1(WT1)peptide combined with AddaVaxTM emulsion vaccine for acute myeloid leukemia.Methods The stability of WT1 peptide in the adjuvant vaccine was evaluated using MALDI-TOF-MS time-of-flight mass spectrometry.Female C57BL/6 mice were randomly divided into PBS group,WT1 peptide group,and WT1 peptide+AddaVaxTMemulsion adjuvant vaccine group.The immunization was performed at a dose of 50 μg/mouse for antigen and 50 μg/mouse for adjuvant,with intramuscular injection on days 0,14,and 28.HE staining was used to assess the toxicity of intramuscular vaccination on mouse organ tissues.Cytokine levels were detected by ELISA,and the number of IFN-γ-secreting splenocytes was measured by ELISpot.Flow cytometry was employed to detect the maturation of bone marrow-derived dendritic cells(BMDCs)promoted by the vaccine in vitro and the promotion for lymphocyte activation,and H-2Db WT1 tetramer was utilized to detect the proportion of specific CD8+T cells.After establishing a mouse leukemia tumor model using the C1498-mWT1 stable cell line,the anti-tumor effects of the vaccine for prevention and treatment were evaluated.Results The WT1 peptide stably existed in the vaccine without causing significant organ tissue changes in mice after intramuscular injection.Compared to the mice immunized with WT1 aqueous solution,the mice after intramuscular injection of the WT1 peptide emulsion adjuvant vaccine showed stronger immune responses of Th1 cells,including IFN-γ and TNF-α,as well as Th17 cells of IL-17A(P＜0.05),and the mice had not only promoted number of IFN-γ secreting splenocytes(P＜0.01)but also enhanced maturation of BMDCs,as indicated by an increase in the proportions of CD40+/CD11c+and CD86+CD80+/CD11c+ cells(P＜0.05).Additionally,there were increases in both the proportion of CD4+/CD3+T and CD69+/CD8+T cells(P＜0.05)and the proportion of specific CD8+T cells(P＜0.05).In the anti-tumor effect study using the C1498-mWT1 mouse model,the median survival time of the WT1+AddaVaxTM group was extended by 6 d compared to the WT1 aqueous solution group.At day 50,the survival rate of mice in the WT1+AddaVaxTM group was still 28.5％,while all mice in the other groups had died(P＜0.05).Conclusion The vaccine with the WT1 peptide and AddaVaxTM emulsion adjuvant exhibits good immunological and anti-tumor effects.