Objective To develop measurement instruments of dynamic capabilities for public hospitals,providing a reference for the evaluation and enhancement of their dynamic capabilities.Methods The initial construction of the measurement instruments of dynamic capabilities for public hospitals was based on literature review and focused group discussions.Two rounds of expert consultation were conducted using the Delphi method,and the reliability and validity of the questionnaire was initially examined through pre-survey.Results The effective response rates for both rounds of consultation were above 85％,with high positive coefficient,the authority coefficients greater than 0.8,and variation coefficients less than 0.25,indicating a high level of consensus among experts.Furthermore,the reliability and validity are acceptable.After integrating expert feedback,the measurement instruments of dynamic capabilities for public hospitals were finalized,encompassing four dimensions:sensing,learning,integration capability,and innovation capabilities.Conclusion The measurement instruments of dynamic capabilities for public hospitals,developed based on the Delphi method,can be applied in the practice of evaluating and enhancing the dynamic capabilities of public hospitals.

BACKGROUND:Non-traumatic necrosis of the femoral head is a difficult joint disease,and preserving one's own femoral head is of great significance for young patients.Currently,there is a lack of regular and unified functional exercise plans.OBJECTIVE:To investigate the effect of hip abductor muscle exercise on the three-dimensional gait and collapse rate of patients with non-traumatic femoral head necrosis,and to provide theoretical basis for effective rehabilitation of patients with non-traumatic femoral head necrosis.METHODS:Totally 81 non-traumatic and non-surgical patients with femoral head necrosis(81 hips)admitted to the Third Affiliated Hospital of Guangzhou University of Chinese Medicine from June 2020 to June 2022 were included.Patients were randomly divided into a control group(n=40)and a hip abductor muscle exercise group(n=41).The control group received routine physical therapy and medication treatment.The hip abductor muscle exercise group underwent hip abductor muscle exercise on the basis of the control group.The gait status(hip joint range of motion,step length difference,and ground contact time difference)of two groups of patients was evaluated using the Tecnobody balance assessment system before and 12 weeks after treatment.The BIODEX-S4 isokinetic muscle strength testing system was used to test the peak force distance of hip abduction isokinetic muscle strength.Gluteus medius width ratio was compared between two groups.The collapse rate was compared between two groups of patients 1 year after treatment.RESULTS AND CONCLUSION:(1)There was no statistically significant difference between the hip abductor muscle exercise group and the control group in terms of age,gender,side profile,body mass index,and etiology(P＞0.05).(2)Before treatment,there was no significant statistical difference in the range of motion of the affected hip joint between the two groups(P＞0.05).After treatment,the range of motion of the affected hip joint in both groups improved compared to before treatment(P＜0.05),and the range of motion of the affected hip joint in the hip abductor muscle exercise group was significantly higher than that in the control group(P＜0.05).(3)Before treatment,there was no significant statistical difference in the step length and touchdown time between the two groups(P＞0.05).12 weeks after treatment,the difference in step length and touchdown time between the two groups decreased compared to before treatment(P＜0.05),and the difference in step length and touchdown time between the hip abductor muscle exercise group after treatment was significantly greater than that of the control group(P＜0.05).(4)Before treatment,there was no significant statistical difference in gluteus medius width ratio between the two groups(P＞0.05).12 weeks after treatment,the gluteus medius width ratio of both groups increased compared to that before treatment(P＜0.05),and the gluteus medius width ratio of the hip abductor muscle exercise group was significantly higher than that of the control group(P＜0.05).(5)At 1 year after treatment,the comparison of femoral head collapse rates between the two groups showed significant statistical significance(P＜0.05),and that in the hip abductor muscle exercise group(22％)was significantly lower than that in the control group(45％).(6)It is concluded that exercise of the hip abductor muscle effectively enhances hip joint function,improves gait,and reduces the rate of femoral head collapse in patients with non-traumatic femoral head necrosis.It is recommended to use hip abductor muscle exercise as one of the basic methods for hip preservation in non-traumatic femoral head necrosis.

BACKGROUND:Non-traumatic necrosis of the femoral head is a difficult joint disease,and preserving one's own femoral head is of great significance for young patients.Currently,there is a lack of regular and unified functional exercise plans.OBJECTIVE:To investigate the effect of hip abductor muscle exercise on the three-dimensional gait and collapse rate of patients with non-traumatic femoral head necrosis,and to provide theoretical basis for effective rehabilitation of patients with non-traumatic femoral head necrosis.METHODS:Totally 81 non-traumatic and non-surgical patients with femoral head necrosis(81 hips)admitted to the Third Affiliated Hospital of Guangzhou University of Chinese Medicine from June 2020 to June 2022 were included.Patients were randomly divided into a control group(n=40)and a hip abductor muscle exercise group(n=41).The control group received routine physical therapy and medication treatment.The hip abductor muscle exercise group underwent hip abductor muscle exercise on the basis of the control group.The gait status(hip joint range of motion,step length difference,and ground contact time difference)of two groups of patients was evaluated using the Tecnobody balance assessment system before and 12 weeks after treatment.The BIODEX-S4 isokinetic muscle strength testing system was used to test the peak force distance of hip abduction isokinetic muscle strength.Gluteus medius width ratio was compared between two groups.The collapse rate was compared between two groups of patients 1 year after treatment.RESULTS AND CONCLUSION:(1)There was no statistically significant difference between the hip abductor muscle exercise group and the control group in terms of age,gender,side profile,body mass index,and etiology(P＞0.05).(2)Before treatment,there was no significant statistical difference in the range of motion of the affected hip joint between the two groups(P＞0.05).After treatment,the range of motion of the affected hip joint in both groups improved compared to before treatment(P＜0.05),and the range of motion of the affected hip joint in the hip abductor muscle exercise group was significantly higher than that in the control group(P＜0.05).(3)Before treatment,there was no significant statistical difference in the step length and touchdown time between the two groups(P＞0.05).12 weeks after treatment,the difference in step length and touchdown time between the two groups decreased compared to before treatment(P＜0.05),and the difference in step length and touchdown time between the hip abductor muscle exercise group after treatment was significantly greater than that of the control group(P＜0.05).(4)Before treatment,there was no significant statistical difference in gluteus medius width ratio between the two groups(P＞0.05).12 weeks after treatment,the gluteus medius width ratio of both groups increased compared to that before treatment(P＜0.05),and the gluteus medius width ratio of the hip abductor muscle exercise group was significantly higher than that of the control group(P＜0.05).(5)At 1 year after treatment,the comparison of femoral head collapse rates between the two groups showed significant statistical significance(P＜0.05),and that in the hip abductor muscle exercise group(22％)was significantly lower than that in the control group(45％).(6)It is concluded that exercise of the hip abductor muscle effectively enhances hip joint function,improves gait,and reduces the rate of femoral head collapse in patients with non-traumatic femoral head necrosis.It is recommended to use hip abductor muscle exercise as one of the basic methods for hip preservation in non-traumatic femoral head necrosis.

Objective To develop measurement instruments of dynamic capabilities for public hospitals,providing a reference for the evaluation and enhancement of their dynamic capabilities.Methods The initial construction of the measurement instruments of dynamic capabilities for public hospitals was based on literature review and focused group discussions.Two rounds of expert consultation were conducted using the Delphi method,and the reliability and validity of the questionnaire was initially examined through pre-survey.Results The effective response rates for both rounds of consultation were above 85％,with high positive coefficient,the authority coefficients greater than 0.8,and variation coefficients less than 0.25,indicating a high level of consensus among experts.Furthermore,the reliability and validity are acceptable.After integrating expert feedback,the measurement instruments of dynamic capabilities for public hospitals were finalized,encompassing four dimensions:sensing,learning,integration capability,and innovation capabilities.Conclusion The measurement instruments of dynamic capabilities for public hospitals,developed based on the Delphi method,can be applied in the practice of evaluating and enhancing the dynamic capabilities of public hospitals.

Objective:To investigate the clinical characteristics and treatment of patients with perianal necrotizing fasciitis.Methods:This study was a retrospective cohort study. Twenty patients with perianal necrotizing fasciitis who met the inclusion criteria were admitted to the Department of Burn and Plastic Surgery of the First Affiliated Hospital of Guangxi Medical University (hereinafter referred to as our department) from August 2013 to September 2023, including 19 males and 1 female, aged 24-74 (56±11) years. Based on the spreading route of perianal infection to the lower abdomen, the patients were divided into perianal-inguinal-lower abdominal wall group (12 cases) and perianal-pelvic cavity-retroperitoneal group (8 cases). The following clinical data were compared between the two groups of patients: general data, including gender, age, combined underlying diseases, blood glucose level and acute physiology and chronic health evaluation Ⅱ (APACHE Ⅱ) score when admitted to our department, and laboratory risk indicator for necrotizing fasciitis (LRINEC) score when admitted to our department and at 14 d after admitted to our department; infection indicators when admitted to our department, including C-reactive protein level, white blood cell count, lymphocyte count, procalcitonin level, and lactic acid level; clinical outcome-related indicators, including time from onset to definite infection range, number of surgery, treatment in intensive care unit (ICU), length of hospital stay, treatment outcome, and recurrence of necrotizing fasciitis during follow-up; detection of pathogen and bacterial drug resistance in wound necrotic tissue specimen when admitted to our department.Results:Compared with those in perianal-inguinal-lower abdominal wall group, the APACHE Ⅱ score and lactic acid level when admitted to our department and LRINEC score at 14 d after admitted to our department (with t values of -5.98, -5.01, and -2.86, respectively, P<0.05) and ICU treatment ratio ( P<0.05) were significantly increased, the time from onset to definite infection range was significantly prolonged ( Z=-3.75, P<0.05), and the number of surgery was significantly increased ( Z=2.80, P<0.05) in patients in perianal-pelvic cavity-retroperitoneal group. There were no statistically significant differences in other data between the two groups of patients ( P>0.05). Eighteen patients were cured, and no recurrence of perianal necrotizing fasciitis was observed during follow-up of 6 months in 18 cured patients. The main bacteria were Escherichia coliand Klebsiella pneumoniae, and the fungui were Aspergillus and Candida albicans detected in wound necrotic tissue specimens in two groups of patients when admitted to our department. The ratio of multiple drug resistance of bacteria in wound necrotic tissue specimens in perianal-pelvic cavity-retroperitoneal group of patients was significantly higher than that in perianal-inguinal-lower abdominal wall group ( P<0.05). Conclusions:Perianal necrotizing fasciitis can spread to the lower abdomen through two routes: the perianal-inguinal-lower abdominal wall route and the perianal-pelvic cavity-retroperitoneal route. The latter is more insidious in disease progression and more challenging in treatment. Establishing a mechanism of multi-disciplinary team diagnosis and treatment can achieve the goal of early diagnosis and precise treatment of perianal necrotizing fasciitis.

Objectives:To investigate the application value of laparoscopic double stapler firings and double stapling technique combined with rectal eversion and total extra-abdominal resection (LDER) in the anal preservation treatment of low rectal cancer.Methods:Inclusion criteria: (1) age was 18-70; (2) the distance of the lower tumor edge from the anal verge was 4-5 cm; (3) primary tumor with a diameter ≤3 cm; (4) preoperative staging of T1~2N1~2M0; (5) "difficult pelvis", defined as ischial tuberosity diameter<10 cm or body mass index>25 kg/m 2; (6) patients with strong intention for sphincter preservation; (7) no preoperative treatment (e.g., chemotherapy, radiotherapy, molecular targeted therapy, or immunotherapy); (8) no lateral lymph node enlargement; (9) no previous anorectal surgery; (10) patients with good basic condition who could tolerate surgery. Exclusion criteria: (1) previously suffered from malignant tumors of the digestive tract or currently suffering from malignant tumors out of the digestive tract; (2) patients with preoperative anal dysfunction (Wexner score ≥ 10), or fecal incontinence. The specific surgical steps are as follows: the distal end of the rectum was dissected to the level of the interspace between internal and external sphincters of anal canal. Five centimeters proximal to the tumor, the mesorectum was ligated, and a liner stapler was used to transect the rectum. The distal rectum with the tumor were then everted and extracted through the anus. The rectum was transected 0.5-1.0 cm distal to the tumor with a linear stapler. Full thickness suture was used to reinforce the stump of the rectum, which was then brought back into the pelvic cavity. Finally, an end-to-end anastomosis between the colon and the rectum was performed. A retrospective descriptive study was performed of the clinical and pathological data of 12 patients with T1-T2 stage low rectal cancer treated with LDER at Henan Provincial People's Hospital from January 2020 to December 2022. Results:All 12 patients successfully completed LDER with sphincter preservation, without conversion to open surgery or changes in surgical approach. The median surgical time was 272 (155-320) minutes, with a median bleeding volume of 100 (50-200) mL. No protective stoma was performed, and all patients received R0 resection. The average hospital stay was 9 (7-15) days. There were no postoperative anastomotic leakage or perioperative deaths. All 12 patients received postoperative follow-up, with a median follow-up of 12 months (6-36 months) and a Wexner score of 8 (5-14) at 6 months postoperatively. There was no tumor recurrence or metastasis during the follow-up period.Conclusions:LDER is safe and effective for the treatment of low rectal cancer.

Objective:To discuss the effect of bone marrow mesenchymal stem cells(BMSCs)-derived exosomes(Exo)on isoproterenol(ISO)-induced myocardial fibrosis in the rats,and to clarify its mechanism.Methods:The Exo was isolated from the BMSCs and characterized by transmission electron microscope,nanoparticle tracking analysis,and Western blotting methods.Forty SD rats were divided into control group,model group,BMSCs-Exo group,and BMSCs-Exo+ferroptosis activator(Erastin)group,and there were 10 rats in each group.The myocardial fibrosis models were established by subcutaneous injection of ISO in all the rats except control group.The rats in BMSCs-Exo and BMSCs-Exo+Erastin groups were given BMSCs-Exo,and the rats in BMSCs-Exo+Erastin group were additionally injected with Erastin intraperitoneally.After 4 weeks,echocardiography was used to detect the left ventricular ejection fraction(LVEF),left ventricular fractional shortening(LVFS),left ventricular end diastolic diameter(LVEDD),and left ventricular end systolic diameter(LVESD)of the rats in various groups;HE staining was used to observe the pathomorphology of myocardium tissue of the rats in various groups;Masson staining was used to observe the fibrosis degrees of myocardium tissue of the rats in various groups;immunohistochemistry was used to detect the positive expression rates of α-smooth muscle actin(α-SMA),type Ⅰ collagen(COL-Ⅰ),and type Ⅲ collagen(COL-Ⅲ)in myocardium tissue of the rats in various groups;colorimetry was used to detect the Fe2+level in myocardium tissue of the rats in various groups;Western blotting method was used to detect the expression levels of acyl-CoA synthetase long chain family member 4(ACSL4),ferritin heavy chain 1(FTH1),glutathione peroxidase 4(GPX4),and solute carrier family 7 member 11(SLC7A11)proteins in myocardium tissue of the rats in various groups.Results:The particles isolated from BMSCs had a typical lipid bilayer structure,and most particle sizes distributed around 100 nm.High expression levels of CD63,CD9,tumor susceptibility gene 101(TSG101),and heat shock protein 70(HSP70)proteins confirmed the particles as Exo.Compared with control group,the LVEF and LVFS of the rats in model group were significantly decreased(P＜0.05),LVEDD and LVESD were increased(P＜0.05),the myocardial cell arrangement was disordered,some nuclear shrinkage and necrosis were seen,the collagen volume fraction(CVF)was significantly increased(P＜0.05),the positive expression rates of α-SMA,COL-Ⅰ,and COL-Ⅲ were significantly increased(P＜0.05),the Fe2+level in myocardium tissue was significantly increased(P＜0.05),the expression level of ACSL4 protein was significantly increased(P＜0.05),and the expression levels of FTH1,GPX4,and SLC7A11 proteins were significantly decreased(P＜0.05).Compared with model group,the LVEF and LVFS of the rats in BMSCs-Exo group were significantly increased(P＜0.05),the LVEDD and LVESD were significantly decreased(P＜0.05),the myocardial tissue damage was significantly alleviated,the CVF was significantly decreased(P＜0.05),the positive expression rates of α-SMA,COL-Ⅰ,and COL-Ⅲ were significantly decreased(P＜0.05),the Fe2+level in myocardium tissue was significantly decreased(P＜0.05),the expression level of ACSL4 protein was significantly decreased(P＜0.05),and the expression levels of FTH1,GPX4,and SLC7A11 proteins were significantly increased(P＜0.05).Compared with BMSCs-Exo group,the LVEF and LVFS of the rats in BMSCs-Exo+Erastin group were significantly decreased(P＜0.05),the LVEDD and LVESD were significantly increased(P＜0.05),the myocardial cell edema and necrosis were seen,the CVF was significantly increased(P＜0.05),the positive expression rates of α-SMA,COL-Ⅰ,and COL-Ⅲ were significantly increased(P＜0.05),the Fe2+level in myocardium tissue was significantly increased(P＜0.05),the expression level of ACSL4 protein was significantly increased(P＜0.05),and the expression levels of FTH1,GPX4,and SLC7A11 proteins were significantly decreased(P＜0.05).Conclusion:BMSC-derived Exo can improve the myocardial fibrosis in the rats induced by ISO,and its mechanism may be related to the inhibition of ferroptosis.

BACKGROUND:Compound Shengmai Chenggu capsule has good therapeutic effects on early steroid-induced osteonecrosis of the femoral head,but the exact mechanism of treatment is not fully understood. OBJECTIVE:To observe the effect of compound Shengmai Chenggu capsule on fucosyltransferase 8,osteogenic gene and Wnt/β-catenin in bone tissue of rats with steroid-induced osteonecrosis of the femoral head. METHODS:Sixty Sprague-Dawley rats were randomized into blank group,model group,low-,middle-,and high-dose drug groups(n=12 per group).In the latter four groups,animal models of steroid-induced osteonecrosis of the femoral head were established by subcutaneous injection of imiquimod(once every 2 weeks,2 times in total)and gluteal muscle injection of methylprednisolone(once a week,4 times in total).The low-,middle-and high-dose drug groups were given 1.89,3.78 and 7.56 g/kg per day compound Shengmai Chenggu capsule solution by gavage respectively on the second day after the last modeling.The same amount of saline was given by gavage to the model group.Administration lasted 8 weeks.After the administration,micro-CT scan,histological staining,compression test,RT-qPCR and western blot were performed on the femoral head. RESULTS AND CONCLUSION:Micro-CT scan results showed that compared with the blank group,trabecular volume fraction,trabecular number and trabecular thickness were significantly decreased(P<0.05),while trabecular separation was increased in the model group(P<0.05).Compared with the model group,the compound Shengmai Chenggu capsule could increase trabecular volume fraction,trabecular number and trabecular thickness(P<0.05),and decrease trabecular separation(P<0.05)in a dose-dependent manner.Hematoxylin-eosin staining results showed that compared with the model group,the rate of empty bone lacunae was reduced in a dose-dependent group in the low-,middle-,and high-dose compound Shengmai Chenggu capsule groups(P<0.05).Immunohistochemical staining results showed that compared with the blank group,the protein expression of fucosyltransferase 8,Runx2 and bone morphogenetic protein 2 was reduced in the model group(P<0.05);compared with the model group,the compound Shengmai Chenggu capsule increased the protein expression of fucosyltransferase 8,Runx2 and bone morphogenetic protein 2 in a dose-dependent manner(P<0.05).Results from the compression test showed that there was a dose-dependent increase in the maximum load and elastic modulus of the femoral head in the low-,middle-,and high-dose compound Shengmai Chenggu capsule groups compared with the model group(P<0.05).RT-qPCR and western blot results showed that the mRNA and protein expressions of fucosyltransferase 8,Runx2,alkaline phosphatase,osteocalcin,osteoblast-specific transcription factor and bone morphogenetic protein 2 were decreased in the model group compared with the blank group(P<0.05);compared with the model group,there was a dose-dependent increase in the mRNA and protein expressions of the above indicators in the low-,middle-,and high-dose compound Shengmai Chenggu capsule groups compared with the model group(P<0.05).Compared with the blank group,the mRNA and protein expression of Wnt2,low-density lipoprotein receptor-related protein 5 and β-catenin were decreased(P<0.05)and the mRNA and protein expressions of glycogen synthase kinase 3β were increased(P<0.05)in the model group;compared with the model group,there was a dose-dependent increase in the mRNA and protein expressions of Wnt2,low-density lipoprotein receptor-related protein 5 and β-catenin(P<0.05)but a dose-dependent decrease in the mRNA and protein expressions of lycogen synthase kinase 3β(P<0.05)in the low-,middle-,and high-dose compound Shengmai Chenggu capsule groups.To conclude,the mechanism by which the compound Shengmai Chenggu capsule treats steroid-induced osteonecrosis of the femoral head may activate the Wnt/β-catenin signaling pathway through the up-regulation of fucosyltransferase 8,thereby promoting bone formation.

BACKGROUND:The majority of studies on developmental dysplasia of the hip focus on hip malformations,but there are few reports on the effects of acetabular dysplasia on the spine. OBJECTIVE:To investigate the compensation of spinopelvic parameters in coronal and sagittal views in patients with developmental dysplasia of the hip,and to explore the correlation between acetabular development and spinopelvic parameters. METHODS:A total of 101 patients with developmental dysplasia of the hip admitted to the Third Affiliated Hospital of Guangzhou University of Chinese Medicine from January 2018 to June 2022 were selected as the trial group,and 114 healthy subjects were selected as the control group during the same period.The spinopelvic parameters of the subjects were measured through the full-length X-ray films of the coronal and sagittal spines:lumbar lordosis,anterior pelvic tilt,thoracolumbar kyphosis,Cobb angle,and the distance between the C7 plumb line and the center sacral vertical line,sacral slope,pelvic incidence,and thoracic kyphosis.The differences in spinopelvic parameters were compared between the two groups.In addition,the differences in spinopelvic parameters in patients with unilateral,bilateral and different Crowe classifications of developmental dysplasia of the hip were compared.Pearson correlation analysis was used to explore the correlation between Sharp angle and spinopelvic parameters. RESULTS AND CONCLUSION:(1)In the sagittal view,the lumbar lordosis in the trial group was significantly lower than that in the control group(P<0.05).The pelvic tilt and kyphosis angle of the thoracolumbar segment in the trial group were significantly greater than those in the control group(P<0.05).In the coronary position,the Cobb angle and the distance between the C7 plumb line and center sacral vertical line in the trial group were significantly greater than those in the control group(P<0.05).There was no significant difference in the remaining spinopelvic parameters between the two groups(P>0.05).(2)The lumbar lordosis of patients with bilateral developmental dysplasia of the hip was significantly lower than that of patients with unilateral developmental dysplasia of the hip(P<0.05).The pelvic tilt,thoracolumbar kyphosis,Cobb angle and the distance between the C7 plumb line and center sacral vertical line in bilateral developmental dysplasia of the hip patients were significantly greater than those in unilateral developmental dysplasia of the hip patients(P<0.05).(3)The lumbar lordosis decreased with the increase of Crowe classification severity(P<0.05).The pelvic tilt increased with the severity of the Crowe classification(P<0.05).(4)Pearson correlation analysis showed that Sharp angle was negatively correlated with lumbar lordosis(P<0.05),while Sharp angle was positively correlated with anterior pelvic tilt,Cobb angle,C7 plumb line and center sacral vertical line(P<0.05).(5)It is concluded that the pelvic tilt,thoracolumbar kyphosis,Cobb angle and the distance between the C7 plumb line and center sacral vertical line increase,while lumbar lordosis decreases in developmental dysplasia of the hip patients.The degree of acetabular dysplasia was significantly correlated with lumbar lordosis,pelvic tilt,Cobb angle,C7 plumb line and center sacral vertical line.

BACKGROUND:The gluteus medius not only abducts the hip joint,but also plays an important role in limiting the external movement of the femoral head.At present,there is a lack of research on the correlation between gluteus medius status and non-traumatic femoral head necrosis. OBJECTIVE:To investigate the relationship between the gluteus medius width ratio and the medial space ratio of the hip joint and the progression of non-traumatic femoral head necrosis,and to explore the effect of gluteus medius atrophy on the surface and necrotic zone stress of the femoral head necrosis through finite element analysis. METHODS:Retrospective analysis of unilateral non-traumatic femoral head necrosis patients admitted to Third Affiliated Hospital of Guangzhou University of Chinese Medicine was performed.All patients were followed up for an average of more than 2 years.They were divided into a collapsed group and a non-collapsed group based on whether there was collapse of the femoral head during the follow-up.Medial space ratio,gluteus medius width ratio,Sharp angle,gluteus medius length ratio,and gluteus medius activation angle were measured and calculated.The differences in these indicators were compared between the two groups.At the first visit and follow-up at 3,6,12,and 24 months,the medial space ratio and gluteus medius width ratio were measured and calculated to explore the changes of these two indicators in the course of non-traumatic femoral head necrosis.In addition,using three-dimensional finite element analysis,a Japanese Investigation Committee classification C1 type femoral head necrosis model was constructed based on CT data.At the same time,based on MRI data,a model of the gluteus medius muscle was constructed and divided into a gluteus medius muscle atrophy group(gluteus medius width ratio:74%-76%)and a gluteus medius muscle normal group(gluteus medius width ratio:94%-96%).Each group constructed 10 models,with 6 degrees of freedom of the distal femur constrained to zero.600 N pressures were applied along the Z-axis to the upper surface of the sacrum.The stress distribution,maximum stress values on the surface and necrotic area of the femoral head,and the maximum displacement of the necrotic area were compared between two groups of models. RESULTS AND CONCLUSION:(1)A total of 153 patients(67 males and 86 females)with 153 hips were included in this study.(2)At the 24-hour follow-up,the medial space ratio of the collapsed group was significantly higher than that of the non-collapsed group(P<0.05).The gluteus medius width ratio of the collapsed group was significantly lower than that of the non-collapsed group(P<0.05).There was no statistically significant difference in Sharp angle,gluteus medius activation angle,and gluteus medius length ratio between the two groups(P>0.05).(3)Since the follow-up time exceeded 3 months,the gluteus medius width ratio of the collapsed group was lower than that of the non-collapsed group(P<0.05).Since the follow-up time exceeded 12 months,the medial space ratio of the collapsed group was higher than that of the non-collapsed group(P<0.05).(4)Pearson correlation analysis showed a significant positive correlation between follow-up time and medial space ratio in the collapsed group(P<0.05),and a significant negative correlation between follow-up time and gluteus medius width ratio(P<0.05).The regression coefficient of gluteus medius width ratio was larger than that of medial space ratio.(5)The group with middle gluteal muscle atrophy showed significant stress concentration on the surface of the femoral head,and the stress zone was significantly located on the outside.The maximum stress on the surface of the femoral head in the group with middle gluteal muscle atrophy was significantly greater than that in the group with normal middle gluteal muscle(P<0.05).There was significant stress concentration in the necrotic area of the middle gluteal muscle atrophy group,and the maximum stress was located at the edge of the necrotic area.The maximum stress and maximum displacement in the necrotic area of the middle gluteal muscle atrophy group were significantly greater than those of the normal group(P<0.05).(6)It is indicated that gluteus medius width ratio is an effective indicator for evaluating changes in gluteal muscle atrophy.In the progression of non-traumatic femoral head necrosis,atrophy of the gluteus medius muscle first occurs,followed by widening of the medial hip joint space.The mechanical mechanism may be that the atrophy of the gluteus medius muscle affects the stability of the hip joint,leading to external displacement of the femoral head,and increasing stress and displacement on the surface and necrotic area of the femoral head.