BACKGROUND:Studies have shown that different durations of pressure application on normal muscles can produce varying physiological responses.OBJECTIVE:To explore the expression levels of inflammatory factors tumor necrosis factor α and nuclear κB in skeletal muscle under different pressure durations.METHODS:Twenty healthy male SPF-grade Sprague-Dawley rats were randomly divided into four groups:control group,10-second pressure group,20-second pressure group,and 30-second pressure group.The right leg of each rat was used for the experiment.The control group received no intervention,while rats in each pressure group were anesthetized by intraperitoneal injection of 2%pentobarbital sodium(35 mg/kg),and the thin femoral muscle of the rats was pressed continuously at a constant pressure of 200 kPa using a homemade mechanical pressure device for 10,20,and 30 seconds,respectively.Muscle tissue at the pressing site of the right hind limb was collected immediately after pressure.Hematoxylin-eosin staining was used to observe the morphological changes of skeletal muscle tissues and changes in the cross-sectional area of muscle fibers,and immunohistochemistry was used to detect the expression levels of tumor necrosis factor α and nuclear factor κB in rat skeletal muscle.RESULTS AND CONCLUSION:Hematoxylin-eosin staining results revealed that the pressure groups showed loosely arranged skeletal muscle fibers,reduced cross-sectional area and diameter,and enlarged intermuscular spaces.Compared with the control group,the cross-sectional area of muscle fibers was significantly reduced in the pressure groups(P<0.05),but there was no significant difference between the three pressure groups(P>0.05).The 10-second pressure group showed no significant presence of red blood cells in the interstitial spaces,while the 20-second pressure group exhibited a small amount of red blood cells,and the 30-second pressure group showed capillary dilation with red blood cells in the interstitial spaces.The expression level of tumor necrosis factor α in the 30-second pressure group was significantly higher than that in the control group(P<0.05).The expression level of nuclear factor κB in skeletal muscle showed no significant difference among groups(P>0.05).To conclude,skeletal muscle undergoes morphological changes and reduced cross-sectional area after pressure at 200 kPa,but there is no significant difference among the 10-,20-,and 30-second pressure groups.As the duration of pressure increases to 30 seconds,the inflammatory factor tumor necrosis factor α is activated,but nuclear factor κB remains unaffected,suggesting that inflammatory factors may express under short-term pressure,while transcription factors show no significant change.

Objective:To investigate the risk factors and their predictive efficacy for early postoperative infection in elderly patients with intertrochanteric femur fracture.Methods:A retrospective cohort study was conducted to analyze the clinical data of 286 elderly patients with intertrochanteric femur fracture admitted to Zhengzhou Orthopedic Hospital between August 2021 and August 2024, including 154 males and 132 females, aged 60-80 years [(72.5±5.8)years]. Fracture involved the left side in 148 patients and the right side in 138 patients. Internal fixation was performed on 214 patients and joint replacement on 72. Based on the occurrence of infection within two weeks postoperatively, the patients were divided into infection group ( n=25) and non-infection group ( n=261). Data were collected from the two groups, including basic information [gender, age, body mass index (BMI), cause of injury, fracture side], admission data (fasting blood glucose, diastolic blood pressure, systolic blood pressure), preoperative data [American Society of Anesthesiologists (ASA) classification, AO classification, serum C-reactive protein (CRP), serum albumin (Alb), serum CRP/Alb ratio, time from injury to surgery], and treatment-related information (surgical type, duration of surgery, intraoperative blood loss, quality of intraoperative reduction, postoperative antibiotic use). Univariate analysis and multivariate Logistic stepwise regression analysis were used to identify independent risk factors for early postoperative infection in elderly patients with intertrochanteric femur fracture. The receiver operating characteristic (ROC) curve was plotted and the area under the curve (AUC) was calculated to evaluate the predictive efficacy of each factor. Results:Univariate analysis showed significant differences between the two groups in fasting blood glucose on admission, preoperative serum CRP, preoperative serum Alb, preoperative serum CRP/Alb ratio, and duration of surgery ( P<0.01). There were no significant differences between the two groups in the remaining variables ( P>0.05). Multivariate Logistic stepwise regression analysis indicated that fasting blood glucose on admission ( OR=2.65, 95% CI 1.32, 5.32, P<0.01), preoperative serum CRP ( OR=1.10, 95% CI 1.04, 1.18, P<0.01), preoperative serum Alb ( OR=0.79, 95% CI 0.70, 0.90, P<0.01), preoperative serum CRP/Alb ( OR=143.78, 95% CI 4.46, 46.77, P<0.01), and duration of surgery ( OR=1.07, 95% CI 1.02, 1.11, P<0.01) were significantly associated with early postoperative infection in elderly patients with intertrochanteric femur fracture. ROC curve analysis showed that the sensitivity and specificity of preoperative serum CRP/Alb in predicting early postoperative infection in elderly patients with intertrochanteric femur fracture were 88.00% and 88.10%, and that the AUC of preoperative serum CRP/Alb prediction was 0.92, significantly greater than the AUC predicted separately by fasting blood glucose at admission, preoperative serum CRP, preoperative serum Alb and duration of surgery (0.76, 0.75, 0.77, 0.76, respectively). The optimal cut-off value for the preoperative serum CRP/Alb ratio was 1.78. Conclusions:Fasting blood glucose on admission, preoperative serum CRP, Alb, CRP/Alb ratio, and duration of surgery are independent risk factors for early postoperative infection in elderly patients with intertrochanteric femur fracture. These factors all possess certain predictive value for early postoperative infection, but the preoperative serum CRP/Alb ratio demonstrates the best predictive efficacy.

BACKGROUND:Studies have shown that different durations of pressure application on normal muscles can produce varying physiological responses.OBJECTIVE:To explore the expression levels of inflammatory factors tumor necrosis factor α and nuclear κB in skeletal muscle under different pressure durations.METHODS:Twenty healthy male SPF-grade Sprague-Dawley rats were randomly divided into four groups:control group,10-second pressure group,20-second pressure group,and 30-second pressure group.The right leg of each rat was used for the experiment.The control group received no intervention,while rats in each pressure group were anesthetized by intraperitoneal injection of 2%pentobarbital sodium(35 mg/kg),and the thin femoral muscle of the rats was pressed continuously at a constant pressure of 200 kPa using a homemade mechanical pressure device for 10,20,and 30 seconds,respectively.Muscle tissue at the pressing site of the right hind limb was collected immediately after pressure.Hematoxylin-eosin staining was used to observe the morphological changes of skeletal muscle tissues and changes in the cross-sectional area of muscle fibers,and immunohistochemistry was used to detect the expression levels of tumor necrosis factor α and nuclear factor κB in rat skeletal muscle.RESULTS AND CONCLUSION:Hematoxylin-eosin staining results revealed that the pressure groups showed loosely arranged skeletal muscle fibers,reduced cross-sectional area and diameter,and enlarged intermuscular spaces.Compared with the control group,the cross-sectional area of muscle fibers was significantly reduced in the pressure groups(P<0.05),but there was no significant difference between the three pressure groups(P>0.05).The 10-second pressure group showed no significant presence of red blood cells in the interstitial spaces,while the 20-second pressure group exhibited a small amount of red blood cells,and the 30-second pressure group showed capillary dilation with red blood cells in the interstitial spaces.The expression level of tumor necrosis factor α in the 30-second pressure group was significantly higher than that in the control group(P<0.05).The expression level of nuclear factor κB in skeletal muscle showed no significant difference among groups(P>0.05).To conclude,skeletal muscle undergoes morphological changes and reduced cross-sectional area after pressure at 200 kPa,but there is no significant difference among the 10-,20-,and 30-second pressure groups.As the duration of pressure increases to 30 seconds,the inflammatory factor tumor necrosis factor α is activated,but nuclear factor κB remains unaffected,suggesting that inflammatory factors may express under short-term pressure,while transcription factors show no significant change.

Objective:To investigate the risk factors and their predictive efficacy for early postoperative infection in elderly patients with intertrochanteric femur fracture.Methods:A retrospective cohort study was conducted to analyze the clinical data of 286 elderly patients with intertrochanteric femur fracture admitted to Zhengzhou Orthopedic Hospital between August 2021 and August 2024, including 154 males and 132 females, aged 60-80 years [(72.5±5.8)years]. Fracture involved the left side in 148 patients and the right side in 138 patients. Internal fixation was performed on 214 patients and joint replacement on 72. Based on the occurrence of infection within two weeks postoperatively, the patients were divided into infection group ( n=25) and non-infection group ( n=261). Data were collected from the two groups, including basic information [gender, age, body mass index (BMI), cause of injury, fracture side], admission data (fasting blood glucose, diastolic blood pressure, systolic blood pressure), preoperative data [American Society of Anesthesiologists (ASA) classification, AO classification, serum C-reactive protein (CRP), serum albumin (Alb), serum CRP/Alb ratio, time from injury to surgery], and treatment-related information (surgical type, duration of surgery, intraoperative blood loss, quality of intraoperative reduction, postoperative antibiotic use). Univariate analysis and multivariate Logistic stepwise regression analysis were used to identify independent risk factors for early postoperative infection in elderly patients with intertrochanteric femur fracture. The receiver operating characteristic (ROC) curve was plotted and the area under the curve (AUC) was calculated to evaluate the predictive efficacy of each factor. Results:Univariate analysis showed significant differences between the two groups in fasting blood glucose on admission, preoperative serum CRP, preoperative serum Alb, preoperative serum CRP/Alb ratio, and duration of surgery ( P<0.01). There were no significant differences between the two groups in the remaining variables ( P>0.05). Multivariate Logistic stepwise regression analysis indicated that fasting blood glucose on admission ( OR=2.65, 95% CI 1.32, 5.32, P<0.01), preoperative serum CRP ( OR=1.10, 95% CI 1.04, 1.18, P<0.01), preoperative serum Alb ( OR=0.79, 95% CI 0.70, 0.90, P<0.01), preoperative serum CRP/Alb ( OR=143.78, 95% CI 4.46, 46.77, P<0.01), and duration of surgery ( OR=1.07, 95% CI 1.02, 1.11, P<0.01) were significantly associated with early postoperative infection in elderly patients with intertrochanteric femur fracture. ROC curve analysis showed that the sensitivity and specificity of preoperative serum CRP/Alb in predicting early postoperative infection in elderly patients with intertrochanteric femur fracture were 88.00% and 88.10%, and that the AUC of preoperative serum CRP/Alb prediction was 0.92, significantly greater than the AUC predicted separately by fasting blood glucose at admission, preoperative serum CRP, preoperative serum Alb and duration of surgery (0.76, 0.75, 0.77, 0.76, respectively). The optimal cut-off value for the preoperative serum CRP/Alb ratio was 1.78. Conclusions:Fasting blood glucose on admission, preoperative serum CRP, Alb, CRP/Alb ratio, and duration of surgery are independent risk factors for early postoperative infection in elderly patients with intertrochanteric femur fracture. These factors all possess certain predictive value for early postoperative infection, but the preoperative serum CRP/Alb ratio demonstrates the best predictive efficacy.