1.Xiaozheng Zhitong Paste Alleviates Bone Cancer Pain by Regulating PD-1/PD-L1-induced Osteoclast Formation
Lu SHANG ; Juanxia REN ; Guangda ZHENG ; Linghan MENG ; Lingyun WANG ; Changlin LI ; Dongtao LI ; Yaohua CHEN ; Guiping YANG ; Yanju BAO
Chinese Journal of Experimental Traditional Medical Formulae 2026;32(5):72-79
ObjectiveThis study aims to investigate the action mechanism by which Xiaozheng Zhitong paste (XZP) alleviates bone cancer pain (BCP) by regulating programmed death protein 1 (PD-1)/programmed death-ligand 1 (PD-L1) pathway-induced osteoclast formation. MethodsThirty female C57BL/6 mice were randomly allocated into the following groups (n=6 per group): normal control group, model group, low‑dose XZP group (31.5 g·kg-1), high‑dose XZP group (63 g·kg-1), and PD‑1 inhibitor (Niv) group. A bone cancer pain (BCP) model was established by injecting Lewis lung carcinoma cells. Mice in the normal control and model groups received topical application of a blank paste matrix at the wound site. Mice in the low‑ and high‑dose XZP groups were treated with XZP applied topically twice daily. Mice in the Niv group were topically administered the blank paste matrix and additionally received Niv via tail‑vein injection every two days. All interventions were continued for 21 days. During this period, behavioral tests were performed to assess mechanical, motor, and thermal nociceptive sensitivities. After 21 days, all mice were euthanized, and bone tissue from the operated side was collected for sectioning and preservation. Tartrate‑resistant acid phosphatase (TRAP) staining was used to evaluate osteoclast expression in the lesioned bone tissue. Immunohistochemistry was performed to detect the expression of Runt‑related transcription factor 2 (Runx2) in the lesioned bone tissue. Immunofluorescence was employed to assess the expression of PD‑1 and PD‑L1 in the lesioned bone tissue. ResultsCompared with the normal group, the model group showed significantly decreased limb mechanical withdrawal threshold, spontaneous paw flinching, and thermal withdrawal latency (P<0.01), increased number of osteoclasts in the lesioned bone tissue (P<0.01), and reduced expression of Runx2 (P<0.01). Compared with the model group, the BCP mice in the XZP low-dose group, XZP high-dose group, and Niv group exhibited increased limb mechanical withdrawal threshold, movement scores, and thermal withdrawal latency (P<0.01). The XZP low-dose group showed no significant changes in osteoclast number or Runx2 expression, while the XZP high-dose group and Niv group demonstrated significantly reduced osteoclast numbers (P<0.01) and significantly increased Runx2 expression (P<0.01). In the lesioned bone tissue of BCP mice, the XZP low-dose group showed no significant decrease in the percentage of PD-1 expression, but a decrease in the percentage of PD-L1 expression (P<0.05). In contrast, both the XZP high-dose group and the Niv group exhibited significant reductions in the percentages of PD-1 and PD-L1 expression (P<0.01). ConclusionXZP alleviates the pain of mice with BCP by blocking the PD-1/PD-L1 pathway to inhibit osteoclastogenesis.
2.Xiaozheng Zhitong Paste Relieves Bone Cancer Pain in Mice by Alleviating Activation of Microglia in Spinal Cord and Damage to Neurons via Blocking PAR2/NF-κB/NLRP3 Pathway
Guangda ZHENG ; Linghan MENG ; Lu SHANG ; Juanxia REN ; Dongtao LI ; Haixiao LIU ; Lingyun WANG ; Changlin LI ; Yaohua CHEN ; Guiping YANG ; Yanju BAO
Chinese Journal of Experimental Traditional Medical Formulae 2026;32(5):91-100
ObjectiveTo investigate the effects and underlying mechanisms of Xiaozheng Zhitong Paste (XZP) on bone cancer pain (BCP). MethodsThirty female BALB/c mice were randomly divided into five groups: a Sham group, a BCP group, a BCP+low-dose XZP group, a BCP+high-dose XZP group, and a BCP+high-dose XZP + protease-activated receptor 2 (PAR2) agonist GB-110 group. BCP mice model was constructed by injecting Lewis lung carcinoma cells into the femoral cavity of the right leg, which was followed by being treated with XZP for 21 d. After 21 d, the mice were sacrificed. Nissl staining was used to evaluate the survival of spinal cord neurons. Immunofluorescence staining was conducted to localize ionized calcium-binding adapter molecule 1 (Iba1) and neuronal nuclear antigen (NeuN) in spinal cord tissue, thereby assessing microglial activation and neuronal survival. Enzyme-linked immunosorbent assay (ELISA) was employed to measure the levels of interleukin-1β (IL-1β), tumor necrosis factor-α (TNF-α), interleukin-6 (IL-6), transforming growth factor-β (TGF-β), interleukin-4 (IL-4), and interleukin-10 (IL-10) in spinal cord tissue. Real-time quantitative polymerase chain reaction (Real-time PCR) was used to detect mRNA expression levels associated with M1/M2 polarization of microglia. Western blot analysis was performed to examine the expression of proteins related to microglial polarization as well as those involved in the PAR2/nuclear factor kappa B (NF-κB)/NOD-like receptor protein 3 (NLRP3) signaling pathway in the spinal cord. ResultsCompared with the Sham group, the spinal cord neurons were damaged, the number of Nissl-positive spinal cord neurons in the spinal cord tissue was significantly reduced (P<0.01), and the rate of NeuN-positive cells was significantly decreased (P<0.01). The spinal cord microglia were activated, the inflammatory level of the spinal cord tissue was enhanced, and Iba1 staining was significantly enhanced (P<0.01). The levels of IL-1β, TNF-α, IL-6, TGF-β, IL-4 and IL-10 were significantly increased (P<0.01). The mRNA expressions of IL-1β, TNF-α and inducible nitric oxide synthase (iNOS) were significantly increased (P<0.01), and the expression of PAR2, NLRP3, ASC and NF-κB p65 proteins in the spinal cord tissue of the BCP mice was significantly enhanced (P<0.01). Compared with the BCP group, high-dose XZP treatment significantly increased the number of Nissl-positive spinal cord neurons in the BCP mice (P<0.01), significantly enhanced the rate of NeuN-positive cells in the spinal cord tissue, and significantly weakened Iba1 staining (P<0.01). In addition, the levels of IL-1β, TNF-α, and IL-6 were significantly decreased, while the levels of TGF-β, IL-4, and IL-10 were significantly increased (P<0.05, P<0.01). The mRNA expression levels of IL-1β, TNF-α, and iNOS were decreased, whereas those of cluster of differentiation 206 (CD206), arginase-1 (Arg-1), and YM1/2 were significantly increased (P<0.05, P<0.01). Low-dose and high-dose XZP treatment significantly decreased the expression of PAR2, NLRP3, ASC, and NF-κB p65 proteins in the spinal cord tissue (P<0.05, P<0.01). These effects could all be significantly eliminated by the PAR2 agonist GB-110. ConclusionXZP can mitigate BCP in mice, which may be achieved through blocking the activated PAR2/NF-κB/NLRP3 pathway.
3.Xiaozheng Zhitong Paste Alleviates Bone Cancer Pain of Mice by Reducing Ferroptosis in Spinal Cord Tissue and Neuronal Damage via Regulating Nrf2/HO-1/GPX4/SLC7A11 Signaling Pathway
Juanxia REN ; Lu SHANG ; Guangda ZHENG ; Linghan MENG ; Lingyun WANG ; Changlin LI ; Dongtao LI ; Yaohua CHEN ; Guiping YANG ; Yanju BAO
Chinese Journal of Experimental Traditional Medical Formulae 2026;32(5):101-113
ObjectiveThe paper aims to investigate the action mechanism by which the Xiaozheng Zhitong paste (XZP) relieves bone cancer pain (BCP). MethodsA model of mice with BCP was established by using Lewis tumor cells. The therapeutic effects of XZP, the ferroptosis inhibitor Ferrostatin-1 (Fer-1), and the nuclear factor erythroid 2-related factor 2 (Nrf2) inhibitor Brusatol (Bru) on BCP were examined. Mice were randomly divided into the Sham operation group, BCP group, BCP+XZP-L group, BCP+XZP-H group, BCP+Fer-1 group, and BCP+XZP-H+Bru group, with six mice in each group. Pain behavior tests were conducted on the mice to assess pain levels. Colorimetric assays were employed to measure ferroptosis-related factors in serum and spinal cord tissue including Fe, malondialdehyde (MDA), reactive oxygen species (ROS), and superoxide dismutase (SOD). Immunofluorescence staining was used to assess ROS production in spinal cord tissue. Transmission electron microscopy was used to observe the ultrastructure of mitochondria in lumbar spinal cord tissue. Quantitative real-time polymerase chain reaction (Real-time PCR) was employed to detect mRNA expression of Nrf2, heme oxygenase-1 (HO-1), glutathione peroxidase 4 (GPX4), and solute carrier family 7 member 11 (SLC7A11) in spinal cord neuron tissue. The protein expression of Nrf2, HO-1, GPX4, and SLC7A11 in spinal cord neurons was measured by Western blot. ResultsCompared with the Sham group, mice in the BCP group exhibited significantly reduced limb usage scores, mechanical foot withdrawal thresholds, and thermal foot withdrawal thresholds (P<0.01). Serum and lumbar spinal cord tissue levels of Fe, MDA, and reactive oxygen species (ROS) were significantly elevated (P<0.05), while superoxide dismutase (SOD) levels were significantly decreased (P<0.05). Lumbar spinal cord mitochondrial structural damage was observed, and mRNA and protein expression of Nrf2, HO-1, GPX4, and SLC7A11 were significantly downregulated (P<0.01). Compared with the BCP group, both low- and high-dose XZP groups improved the aforementioned pain behavioral indicators (P<0.05,P<0.01), reduced ferroptosis-related biomarkers including Fe, MDA, and ROS levels (P<0.05), increased SOD levels (P<0.05,P<0.01), alleviated mitochondrial damage, and upregulated Nrf2, HO-1, GPX4, SLC7A11 mRNA and protein expression (P<0.05,P<0.01). The high-dose XZP group exhibited comparable efficacy to Fer-1 in alleviating pain and inhibiting ferroptosis. Following Bru administration, XZP's effects on pain behavioral indicators, regulation of ferroptosis-related markers, mitochondrial structural protection, and activation of the Nrf2/HO-1/GPX4/SLC7A11 pathway were significantly reversed (P<0.05,P<0.01). ConclusionExternal application of XZP alleviates pain symptoms in BCP mice by activating the Nrf2/HO-1/GPX4/SLC7A11 pathway, thereby inhibiting ferroptosis and neuronal damage in spinal cord neurons.
4.Discussion on Treatment of Cancer Pain with Modified Wumeiwan Based on Jueyin Syndrome
Haixiao LIU ; Linghan MENG ; Guangda ZHENG ; Dongtao LI ; Lu SHANG ; Juanxia REN ; Changlin LI ; Lingyun WANG ; Yanju BAO
Chinese Journal of Experimental Traditional Medical Formulae 2026;32(5):124-128
Pain, as one of the most common symptoms in cancer patients, seriously affects the survival quality of patients. The three-step pain relief program currently used in clinical practice cannot completely relieve pain in cancer patients and is accompanied by many problems. From the perspective of Jueyin syndrome in traditional Chinese medicine (TCM), this paper believed that the core pathogenesis of cancer pain was declined healthy Qi and cold and heat in complexity, and used Wumeiwan as the main formula with modification according to syndrome for clearing the upper, warming the lower part of the body, and harmonizing the cold and heat. It can regulate the pathological environment of deficiency, cold, stasis, toxicity, and heat, and restore the physiological function of Yang transforming Qi while Yin constituting form, so as to prevent, relieve, and even eliminate cancer pain, having achieved good clinical efficacy. It can not only help cancer patients relieve pain, but also control tumor and eliminate tumor, achieving a dual benefit of pain relief and tumor suppression. It gives full play to the characteristics and advantages of syndrome differentiation and treatment in TCM, and expands the scope of ZHANG Zhongjing's treatment for Jueyin syndrome, which provides ideas for the clinical diagnosis and treatment of cancer pain from the perspective of deficiency-excess in complexity and cold and heat in complexity.
5.Characteristics of 150 patients with spinal cord injury complicated with spasticity
Xiaolei LU ; Yiji WANG ; Genlin LIU ; Ying ZHENG ; Chunxia HAO ; Ying ZHANG ; Haiqiong KANG ; Bo WEI ; Qianru MENG ; Hongjun ZHOU
Chinese Journal of Rehabilitation Theory and Practice 2026;32(4):393-398
ObjectiveTo analyze the characteristics of 150 patients with spinal cord injury complicated with spasticity. MethodsA cross-sectional survey was conducted on 150 patients with spinal cord injury accompanied by spasticity from September, 2019 to December, 2024. Their age, gender, cause of injury, injury site, severity of injury, spasticity severity and other indicators were recorded. The relationships between different characteristics were analyzed, and a correlation analysis of disease duration, spasticity grade, injury level, injury severity and age were conducted. ResultsThere was no significant difference in age distribution between patients with tetraplegia and paraplegia (Z = 0.806, P = 0.420). The proportions of trauma (χ2 = 3.982, P = 0.046) and tetraplegia (χ2 = 10.559, P = 0.010) were higher in males than in females. Trauma was the main cause of injury in both tetraplegia and paraplegia patients; the proportion of tetraplegia was higher than paraplegia in trauma patients, while paraplegia was higher than tetraplegia in non-trauma patients (χ2 = 11.885, P < 0.001). Patients with tetraplegia was dominated by incomplete injury, whereas patients with paraplegia was dominated by complete injury (χ2 = 10.885, P = 0.012). Grade A injury was predominant in trauma patients (P = 0.003). Spasticity grade showed a very weak positive correlation with disease duration (r = 0.175, P = 0.032) and age (r = 0.168, P = 0.040). Injury severity showed a very weak positive correlation with age (r = 0.183, P = 0.025). ConclusionCharacteristics of patients with spinal cord injury complicated with spasticity is different with gender, cause of injury, injury level, injury severity.
6.The Role and Regulatory Mechanisms of FOXO1 in Hepatic Lipid Deposition
Meng JIA ; Fang-Hui LI ; Shi-Zhan YAN ; Ai-Ju LI ; Yi-Le WANG ; Pin-Shi NI ; Jia-Han HE ; Yin-Lu LI
Progress in Biochemistry and Biophysics 2026;53(4):905-919
Metabolic associated fatty liver disease (MAFLD) is fundamentally driven by an imbalance in hepatic fatty-acid flux: the influx of fatty acids exceeds the liver’s capacity for disposal, resulting in excessive hepatic lipid accumulation, predominantly in the form of triglycerides (TGs). The occurrence and progression of MAFLD depend on disordered regulation across multiple metabolic steps, including fatty-acid uptake, de novo lipogenesis (DNL), fatty-acid oxidation (FAO), and very low-density lipoprotein (VLDL) export. Forkhead box protein O1 (FOXO1) is a key transcriptional regulator within the hepatic network coordinating glucose and lipid metabolism. Under metabolic stress and insulin resistance (IR), FOXO1 expression is frequently increased, whereas its inhibitory phosphorylation is reduced. These changes enhance FOXO1 nuclear localization and transcriptional activity, thereby reprogramming the expression of genes related to metabolism in the liver. Because hepatic lipid deposition is the central pathological feature of MAFLD, the functional status of FOXO1 directly influences hepatic lipid homeostasis. Growing evidence suggests that FOXO1 can exert bidirectional, environment-dependent effects on hepatic lipid accumulation; however, the molecular basis for this functional switch remains incompletely understood. This review systematically summarizes the biological functions and regulatory mechanisms of FOXO1 and its roles in hepatic lipid metabolism, with a particular focus on its crosstalk with insulin signaling. FOXO1 expression is shaped by RNA modifications and epigenetic regulation mediated by non-coding RNAs. Its transcriptional output is precisely governed by post-translational modifications—such as phosphorylation and acetylation—as well as by coordinated nucleocytoplasmic shuttling. Notably, these regulatory patterns vary markedly across nutritional states, degrees of insulin resistance, and stages of disease. In the fed state, insulin/IGF-1 signaling activates the PI3K-AKT pathway, promoting the inhibitory phosphorylation of FOXO1 and facilitating additional modifications, including acetylation, methylation, and ubiquitination. Together, these events drive FOXO1 export from the nucleus and dampen its transcriptional activity, suppressing gluconeogenesis and constraining lipogenic programs. Conversely, during fasting or when insulin signaling is weakened, FOXO1 inhibition is relieved. FOXO1 accumulates in the nucleus, binds to DNA, and regulates the transcription of downstream target genes. Mechanistically, FOXO1 can aggravate hepatic lipid accumulation by activating genes involved in TG synthesis while repressing FAO-related pathways, thereby favoring storage over oxidation. However, under specific conditions, FOXO1 may also alleviate the hepatic lipid burden by promoting TG hydrolysis and enhancing VLDL secretion, thereby reducing the net hepatic lipid load. In addition, lipotoxic signals mediated by ceramides and diacylglycerols (Cer/DAG) activate atypical protein kinase C (aPKC), further exacerbating the disruption of the AKT-FOXO1 axis. This vicious cycle ultimately produces a metabolic paradox in which increased hepatic glucose output coexists with persistent, insulin-independent lipogenesis, accelerating MAFLD progression. Importantly, FOXO1 regulation is not uniform: during early metabolic overload, insulin-mediated suppression may remain effective, whereas in advanced insulin resistance, the loss of AKT control permits sustained FOXO1 activity. Such stage-dependent dynamics may help explain why FOXO1 can either promote steatosis or, in certain contexts, support programs that facilitate lipid turnover. Accordingly, interventions should be liver-specific and tuned to the disease stage, aiming to curb maladaptive FOXO1 signaling while preserving its capacity to promote triglyceride hydrolysis and VLDL secretion when advantageous. Overall, this review offers an important perspective on MAFLD pathogenesis, emphasizing FOXO1 as a potential therapeutic target and providing a theoretical basis for developing liver-specific, disease-course-dependent precision interventions.
7.Establishment and Preliminary Analysis of GP73 Interactome Using Proximity-dependent Labeling Technology
Mu-Yi LIU ; Chang ZHANG ; Meng-Xin YANG ; Xin-Long YAN ; Lu-Ming WAN ; Cong-Wen WEI
Progress in Biochemistry and Biophysics 2026;53(3):711-723
ObjectiveProtein-protein interactions (PPIs) are fundamental to the execution of biological functions within living cells. However, traditional biochemical methods, such as co-immunoprecipitation (Co-IP), often fail to capture transient, weak, or membrane-associated interactions due to the stringent detergent requirements for cell lysis. Proximity labeling (PL) has emerged in recent years as a transformative technology for mapping the proteomes of specific subcellular compartments and identifying dynamic interactomes in situ. Golgi protein 73 (GP73, also known as GOLPH2), a resident type II Golgi transmembrane protein, is a well-recognized clinical biomarker for liver diseases, including hepatocellular carcinoma (HCC). Despite its clinical significance, the comprehensive physiological and pathological functions of GP73 remain partially understood. This study aims to establish an APEX2-mediated proximity labeling system specifically targeting GP73 to map its interactome in a living cellular environment, thereby providing new insights into its molecular roles and regulatory mechanisms. MethodsTo achieve spatial specificity, we first constructed a stable cell line expressing a fusion protein consisting of GP73 and the engineered soybean peroxidase APEX2. The localization of the GP73-APEX2 fusion protein was validated to ensure it correctly targeted the Golgi apparatus. The proximity labeling reaction was initiated by incubating the cells with biotin-phenol (BP) for 30 min, followed by a brief (1 min) treatment with1 mmol/L hydrogen peroxide (H2O2). This catalytic reaction converts BP into highly reactive, short-lived biotin-phenoxyl radicals that covalently attach to endogenous proteins within a small labeling radius of the GP73-APEX2 enzyme. Subsequently, the cells were quenched, and biotinylated proteins were enriched using high-affinity streptavidin-coated magnetic beads. The captured “neighbor” proteins were subjected to on-bead digestion and analyzed via liquid chromatography-tandem mass spectrometry (LC-MS/MS) for high-throughput identification. Rigorous bioinformatics analysis, including Gene Ontology (GO) enrichment, Kyoto Encyclopedia of Genes and Genomes (KEGG) pathway analysis, and protein-protein interaction network mapping, was performed to interpret the biological significance of the identified candidates. ResultsOur results demonstrate the successful establishment of a robust and sensitive APEX2-based proximity labeling system for GP73. We identified a total of 95 high-confidence interacting proteins that were significantly enriched in the GP73 proximity proteome compared to control groups. Bioinformatics analysis revealed that these interactors were predominantly associated with biological processes such as vesicular transport, protein localization, and, most notably, molecular functions related to “ribosome binding” and “translation regulation”. This suggested an unexpected role for the Golgi-resident GP73 in the cellular translation machinery. To validate these findings, we performed targeted biochemical assays which confirmed a direct interaction between GP73 and the subunits of the eukaryotic translation initiation factor 3 (eIF3) complex, specifically EIF3G and EIF3I. Furthermore, functional validation using the surface sensing of translation (SUnSET) assay—a non-radioactive method to monitor protein synthesis—revealed that the overexpression of GP73 significantly promoted global protein translation levels in the cell, whereas its depletion or inhibition resulted in reduced translation efficiency. ConclusionThis study successfully utilized APEX2-mediated proximity labeling to provide the first systematic map of GP73 interactome in living cells. Our findings uncover a novel, unconventional function of GP73 as a regulator of cellular protein translation, likely mediated through its interaction with the eIF3 complex. This discovery significantly broadens our understanding of the biological roles of GP73 beyond its traditional function in the Golgi apparatus and suggests that it may act as a bridge between Golgi-related trafficking and the protein synthesis machinery. Furthermore, the technical framework established in this study provides a valuable template for investigating other complex organelle-associated protein networks and resolving transient macromolecular interactions in various physiological and pathological contexts.
8.Surgical treatment of hepatic alveolar echinococcosis: challenges and innovations
Pei ZHANG ; Lu ZHAO ; Yunfei FANG ; Hui YANG ; Yifan WANG ; Yanqiong MA ; Yu MENG
Organ Transplantation 2026;17(3):512-518
Hepatic alveolar echinococcosis is a highly invasive zoonotic parasitic disease with poor prognosis. Surgical intervention serves as the pivotal approach to achieve radical cure and improve the prognosis of hepatic alveolar echinococcosis patients. In recent years, with the popularization of the concept of precision surgery and the development of the multidisciplinary diagnosis and treatment model, the surgical treatment strategies for hepatic alveolar echinococcosis have been continuously enriched, and the selection of surgical procedures has become increasingly diversified. Although key surgical techniques such as radical hepatectomy, autologous liver transplantation and allogeneic liver transplantation have achieved remarkable progress in clinical application, many insurmountable challenges still remain. Therefore, by sorting out the latest evidence-based advances in the field of surgical treatment for hepatic alveolar echinococcosis, this article focuses on discussing the application status and bottlenecks of radical hepatectomy, autologous liver transplantation and allogeneic liver transplantation in hepatic alveolar echinococcosis, aiming to provide a reference for the clinical treatment of hepatic alveolar echinococcosis.
9.Finite element analysis of stress distribution of anchors at different implantation depths under different bone density conditions in rotator cuff tears
Meng WANG ; Tan LU ; Minjie LI ; Zhicheng LIU ; Xiaoyong GUO
Chinese Journal of Tissue Engineering Research 2026;30(3):561-569
BACKGROUND:Arthroscopic anchor repair has become the main treatment method for rotator cuff tears at present.Among them,the insertion status of the anchor is a key factor in the success or failure of the operation.However,currently,the impact of the insertion depth of the anchor on the stress of the bone tunnel and the anchor under different bone density conditions remains unclear.OBJECTIVE:To explore the stress distribution of the bone tunnel and the anchor when the insertion depth of the anchor varies under different bone density conditions by using three-dimensional finite element analysis technology.METHODS:The CT image data of the humerus of volunteers were collected,and the models of the humerus and the anchor were constructed by using Mimics,3-Matic,and Solidworks software.In 3-Matic,holes with distances of 0,2,4,6,and 8 mm from the surface of the humerus were respectively created at the same position of the humerus and assembled with the anchor.In Mimics,values were assigned based on the CT gray value to obtain a model with normal bone mass(T value ≥-1.0).The parameters were changed to construct models with reduced bone mass(-2.5<T value<-1.0)and osteoporosis(T value<-2.5).In each model,a 70 N pulling force was applied to the anchor along the direction tangent to the inner edge of the bone tunnel.The stress distribution and magnitude of the bone tunnel and the anchor when inserted at different depths under different bone density conditions were observed.RESULTS AND CONCLUSION:(1)When the insertion depth was the same,as the bone density decreased,the maximum equivalent stress of the anchor increased,while the maximum equivalent stress of the bone tunnel decreased.(2)When the bone density was the same,as the insertion depth of the anchor increased,the maximum equivalent stress of the anchor decreased.When the insertion depth was 4 mm,the stress of the bone tunnel was the smallest and the distribution was relatively uniform.The stress of the anchor was mainly distributed around the lower anchor hole and the proximal thread,and the stress of the bone tunnel was mainly at the part in contact with the proximal thread.The increase in the insertion depth would change the uniformity and pattern of the stress distribution,while the bone density had a relatively small impact on the stress distribution pattern.(3)It is concluded that the bone density of the humerus is crucial for the anchor repair of rotator cuff tears.It is recommended that clinicians measure the bone density of the greater tuberosity of the humerus before the operation.Excessive insertion depth of the anchor does not significantly increase its stability.Clinicians can conduct personalized preoperative assessments by using the finite element analysis method in combination with the actual situation of patients to achieve the best surgical results.
10.Finite element analysis of stress distribution of anchors at different implantation depths under different bone density conditions in rotator cuff tears
Meng WANG ; Tan LU ; Minjie LI ; Zhicheng LIU ; Xiaoyong GUO
Chinese Journal of Tissue Engineering Research 2026;30(3):561-569
BACKGROUND:Arthroscopic anchor repair has become the main treatment method for rotator cuff tears at present.Among them,the insertion status of the anchor is a key factor in the success or failure of the operation.However,currently,the impact of the insertion depth of the anchor on the stress of the bone tunnel and the anchor under different bone density conditions remains unclear.OBJECTIVE:To explore the stress distribution of the bone tunnel and the anchor when the insertion depth of the anchor varies under different bone density conditions by using three-dimensional finite element analysis technology.METHODS:The CT image data of the humerus of volunteers were collected,and the models of the humerus and the anchor were constructed by using Mimics,3-Matic,and Solidworks software.In 3-Matic,holes with distances of 0,2,4,6,and 8 mm from the surface of the humerus were respectively created at the same position of the humerus and assembled with the anchor.In Mimics,values were assigned based on the CT gray value to obtain a model with normal bone mass(T value ≥-1.0).The parameters were changed to construct models with reduced bone mass(-2.5<T value<-1.0)and osteoporosis(T value<-2.5).In each model,a 70 N pulling force was applied to the anchor along the direction tangent to the inner edge of the bone tunnel.The stress distribution and magnitude of the bone tunnel and the anchor when inserted at different depths under different bone density conditions were observed.RESULTS AND CONCLUSION:(1)When the insertion depth was the same,as the bone density decreased,the maximum equivalent stress of the anchor increased,while the maximum equivalent stress of the bone tunnel decreased.(2)When the bone density was the same,as the insertion depth of the anchor increased,the maximum equivalent stress of the anchor decreased.When the insertion depth was 4 mm,the stress of the bone tunnel was the smallest and the distribution was relatively uniform.The stress of the anchor was mainly distributed around the lower anchor hole and the proximal thread,and the stress of the bone tunnel was mainly at the part in contact with the proximal thread.The increase in the insertion depth would change the uniformity and pattern of the stress distribution,while the bone density had a relatively small impact on the stress distribution pattern.(3)It is concluded that the bone density of the humerus is crucial for the anchor repair of rotator cuff tears.It is recommended that clinicians measure the bone density of the greater tuberosity of the humerus before the operation.Excessive insertion depth of the anchor does not significantly increase its stability.Clinicians can conduct personalized preoperative assessments by using the finite element analysis method in combination with the actual situation of patients to achieve the best surgical results.

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