Objective: To evaluate the feasibility of dynamic contrast-enhanced MRI (DCE-MRI) in differentiating tumor deposits (TDs) from metastatic lymph nodes (MLNs) in rectal cancer. Materials and Methods: A retrospective analysis was conducted on 70 patients with rectal cancer, including 168 lesions (70 TDs and 98 MLNs confirmed by histopathology), who underwent pretreatment MRI and subsequent surgery between March 2019 and December 2022. The morphological characteristics of TDs and MLNs, along with quantitative parameters derived from DCE-MRI (K trans , kep, and v e) and DWI (ADCmin, ADCmax, and ADCmean), were analyzed and compared between the two groups.Multivariable binary logistic regression and receiver operating characteristic (ROC) curve analyses were performed to assess the diagnostic performance of significant individual quantitative parameters and combined parameters in distinguishing TDs from MLNs. Results: All morphological features, including size, shape, border, and signal intensity, as well as all DCE-MRI parameters showed significant differences between TDs and MLNs (all P < 0.05). However, ADC values did not demonstrate significant differences (all P > 0.05). Among the single quantitative parameters, v e had the highest diagnostic accuracy, with an area under the ROC curve (AUC) of 0.772 for distinguishing TDs from MLNs. A multivariable logistic regression model incorporating short axis, border, v e, and ADC mean improved diagnostic performance, achieving an AUC of 0.833 (P = 0.027). Conclusion The combination of morphological features, DCE-MRI parameters, and ADC values can effectively aid in the preoperative differentiation of TDs from MLNs in rectal cancer.

Objective: To evaluate the feasibility of dynamic contrast-enhanced MRI (DCE-MRI) in differentiating tumor deposits (TDs) from metastatic lymph nodes (MLNs) in rectal cancer. Materials and Methods: A retrospective analysis was conducted on 70 patients with rectal cancer, including 168 lesions (70 TDs and 98 MLNs confirmed by histopathology), who underwent pretreatment MRI and subsequent surgery between March 2019 and December 2022. The morphological characteristics of TDs and MLNs, along with quantitative parameters derived from DCE-MRI (K trans , kep, and v e) and DWI (ADCmin, ADCmax, and ADCmean), were analyzed and compared between the two groups.Multivariable binary logistic regression and receiver operating characteristic (ROC) curve analyses were performed to assess the diagnostic performance of significant individual quantitative parameters and combined parameters in distinguishing TDs from MLNs. Results: All morphological features, including size, shape, border, and signal intensity, as well as all DCE-MRI parameters showed significant differences between TDs and MLNs (all P < 0.05). However, ADC values did not demonstrate significant differences (all P > 0.05). Among the single quantitative parameters, v e had the highest diagnostic accuracy, with an area under the ROC curve (AUC) of 0.772 for distinguishing TDs from MLNs. A multivariable logistic regression model incorporating short axis, border, v e, and ADC mean improved diagnostic performance, achieving an AUC of 0.833 (P = 0.027). Conclusion The combination of morphological features, DCE-MRI parameters, and ADC values can effectively aid in the preoperative differentiation of TDs from MLNs in rectal cancer.

Objective: To evaluate the feasibility of dynamic contrast-enhanced MRI (DCE-MRI) in differentiating tumor deposits (TDs) from metastatic lymph nodes (MLNs) in rectal cancer. Materials and Methods: A retrospective analysis was conducted on 70 patients with rectal cancer, including 168 lesions (70 TDs and 98 MLNs confirmed by histopathology), who underwent pretreatment MRI and subsequent surgery between March 2019 and December 2022. The morphological characteristics of TDs and MLNs, along with quantitative parameters derived from DCE-MRI (K trans , kep, and v e) and DWI (ADCmin, ADCmax, and ADCmean), were analyzed and compared between the two groups.Multivariable binary logistic regression and receiver operating characteristic (ROC) curve analyses were performed to assess the diagnostic performance of significant individual quantitative parameters and combined parameters in distinguishing TDs from MLNs. Results: All morphological features, including size, shape, border, and signal intensity, as well as all DCE-MRI parameters showed significant differences between TDs and MLNs (all P < 0.05). However, ADC values did not demonstrate significant differences (all P > 0.05). Among the single quantitative parameters, v e had the highest diagnostic accuracy, with an area under the ROC curve (AUC) of 0.772 for distinguishing TDs from MLNs. A multivariable logistic regression model incorporating short axis, border, v e, and ADC mean improved diagnostic performance, achieving an AUC of 0.833 (P = 0.027). Conclusion The combination of morphological features, DCE-MRI parameters, and ADC values can effectively aid in the preoperative differentiation of TDs from MLNs in rectal cancer.

Objective: To evaluate the feasibility of dynamic contrast-enhanced MRI (DCE-MRI) in differentiating tumor deposits (TDs) from metastatic lymph nodes (MLNs) in rectal cancer. Materials and Methods: A retrospective analysis was conducted on 70 patients with rectal cancer, including 168 lesions (70 TDs and 98 MLNs confirmed by histopathology), who underwent pretreatment MRI and subsequent surgery between March 2019 and December 2022. The morphological characteristics of TDs and MLNs, along with quantitative parameters derived from DCE-MRI (K trans , kep, and v e) and DWI (ADCmin, ADCmax, and ADCmean), were analyzed and compared between the two groups.Multivariable binary logistic regression and receiver operating characteristic (ROC) curve analyses were performed to assess the diagnostic performance of significant individual quantitative parameters and combined parameters in distinguishing TDs from MLNs. Results: All morphological features, including size, shape, border, and signal intensity, as well as all DCE-MRI parameters showed significant differences between TDs and MLNs (all P < 0.05). However, ADC values did not demonstrate significant differences (all P > 0.05). Among the single quantitative parameters, v e had the highest diagnostic accuracy, with an area under the ROC curve (AUC) of 0.772 for distinguishing TDs from MLNs. A multivariable logistic regression model incorporating short axis, border, v e, and ADC mean improved diagnostic performance, achieving an AUC of 0.833 (P = 0.027). Conclusion The combination of morphological features, DCE-MRI parameters, and ADC values can effectively aid in the preoperative differentiation of TDs from MLNs in rectal cancer.

Objective: To evaluate the feasibility of dynamic contrast-enhanced MRI (DCE-MRI) in differentiating tumor deposits (TDs) from metastatic lymph nodes (MLNs) in rectal cancer. Materials and Methods: A retrospective analysis was conducted on 70 patients with rectal cancer, including 168 lesions (70 TDs and 98 MLNs confirmed by histopathology), who underwent pretreatment MRI and subsequent surgery between March 2019 and December 2022. The morphological characteristics of TDs and MLNs, along with quantitative parameters derived from DCE-MRI (K trans , kep, and v e) and DWI (ADCmin, ADCmax, and ADCmean), were analyzed and compared between the two groups.Multivariable binary logistic regression and receiver operating characteristic (ROC) curve analyses were performed to assess the diagnostic performance of significant individual quantitative parameters and combined parameters in distinguishing TDs from MLNs. Results: All morphological features, including size, shape, border, and signal intensity, as well as all DCE-MRI parameters showed significant differences between TDs and MLNs (all P < 0.05). However, ADC values did not demonstrate significant differences (all P > 0.05). Among the single quantitative parameters, v e had the highest diagnostic accuracy, with an area under the ROC curve (AUC) of 0.772 for distinguishing TDs from MLNs. A multivariable logistic regression model incorporating short axis, border, v e, and ADC mean improved diagnostic performance, achieving an AUC of 0.833 (P = 0.027). Conclusion The combination of morphological features, DCE-MRI parameters, and ADC values can effectively aid in the preoperative differentiation of TDs from MLNs in rectal cancer.

The working principle and development of flexible semiconductor devices based on organic field effect transistor(OFET)technology were introduced.The current research status of OFET-based wearable flexible monitoring devices were reviewed,including biomechanical monitoring devices,tattoo biomonitoring devices and cellular detection devices and etc.The deficiencies of OFET-based wearable flexible monitoring devices were analyzed,and it's pointed out that miniaturization,personalization and diversification were the directions for the development of the future OFET-based wearable flexible moni-toring devices.[Chinese Medical Equipment Journal,2024,45(1):93-100]

BACKGROUND:The treatment of distal tibial comminuted fractures with soft tissue injury has always been challenging.The new retrograde tibial nailing and supercutaneous locking plate are important treatment methods,but their strain and stress shielding at the fracture end during different periods of fracture healing and different load conditions have not been reported. OBJECTIVE:To explore the biomechanical stability of retrograde tibial nailing and supercutaneous locking plate in different periods of fracture healing by finite element analysis to offer a scientific foundation for clinical application and rehabilitation exercise. METHODS:The finite element model of distal tibial comminuted fracture was established by utilizing the CT data of the tibia from a 40-year-old healthy male.Retrograde tibial nailing,supercutaneous locking plate,and callus models were assembled in accordance with the principle of fracture fixation.The finite element analysis was performed using ANSYS software to compare the displacement of the fracture end,the stress shielding of the tibia,the stress of the callus,and the stress distribution of the tibia and the fixation device during different periods of fracture healing. RESULTS AND CONCLUSION:(1)The relative displacement of the tibial fracture decreased gradually with the healing of the fracture,and the displacement decreased significantly after 3 months.At 0 and 1 months after operation,the vertical displacement and total displacement of the supercutaneous locking plate group were higher than those in the retrograde intramedullary nail group.The Z-axis displacement(horizontal medial and lateral displacement)of the two fixation methods was more obvious than the X-axis and Y-axis,and the Z-axis displacement of supercutaneous locking plate group was the most obvious.The maximum Z-axis displacement of the two fixation methods was located on the outside of the tibia,and the minimum displacement was located on the inside of the tibia.(2)The stress shielding rate at different periods of fracture healing gradually decreased with time.The stress shielding rate of the retrograde intramedullary nail was higher than that of the supercutaneous locking plate at different stages of fracture healing.After 3 months,the stress shielding rate of the supercutaneous locking plate was reduced to about 4%,and the stress shielding rate of the retrograde intramedullary nail was reduced to about 40%.(3)The stress of the stress concentration site of the callus in the two fixation methods increased with the increase of the load,and the stress of the callus in the supercutaneous locking plate group was always greater than that in the retrograde intramedullary nail group.The maximum stress distribution of the callus was approximately equally distributed among the two modes of fixation,both in the lateral portion of the tibia.(4)As the fracture healed,the maximum stress of the tibia in the two groups decreased gradually,and the stress in the supercutaneous locking plate group was always greater than that in the retrograde intramedullary nail group.The average stress of the maximum stress area of the tibia in the supercutaneous locking plate group under 1 500 N load was 285 MPa,while that in the retrograde intramedullary nail group was 26 MPa.(5)As the fracture healed,the stress of the fixation device in the two groups decreased gradually,and the stress in the supercutaneous locking plate group was significantly higher than that in the retrograde intramedullary nail group.After 3 months,the stress of the two fixation devices decreased significantly.(6)It is indicated that in the early stage of fracture healing,the strain on the fracture end in the retrograde intramedullary nail group is small,and the maximum stress of the tibia is moderate,allowing early loaded.The fractured ends in the supercutaneous locking plate group had too large strain and too large maximum stress of the tibia,which needed to be partially loaded under protection and could not be fully loaded.In the middle and late stages of fracture healing,the tibial retrograde intramedullary nail and the supercutaneous locking plate could be completely loaded,and the stress shielding rate of the supercutaneous locking plate was significantly lower than the tibial retrograde intramedullary nail.

Objective:To explore the risk factors for complications related to internal fixation after Inter-Tan intramedullary nail fixation in the treatment of intertrochanteric fractures in elderly patients.Methods:A retrospective cohort study was conducted to analyze the clinical data of 314 elderly patients with intertrochanteric fractures admitted to the Seventh Medical Center of the Chinese PLA General Hospital from January 2016 to December 2020, including 100 males and 214 females, aged 60-98 years [(80.2±8.2)years]. All the patients underwent Inter-Tan intramedullary nail fixation. According to the 2018 AO/OTA classification, 103 patients were with stable fractures and 211 with unstable fractures. The patients were further divided into complication groups and non-complication groups according to the presence of the complications during the follow-up. Six patients (5.8%) with stable fractures had the complications including nonunion in 4 and cut-out in 2. Twenty-eight patients (13.3%) with unstable fractures developed the complications, including nonunion in 5, cut-out in 20, cut-through in 1, and broken nails in 2. With the internal fixation-related complications after surgery as dependent variables, and gender, age, complications [hypertension, coronary heart disease, arrhythmia, pulmonary infection, chronic obstructive pulmonary disease (COPD), renal insufficiency, diabetes], bone density, waiting time for surgery, anesthesia method, reduction method, reduction quality, tip-apex distance, head screw displacement and other influencing factors as independent variables, univariate and multivariate Logistic regression analyses were conducted on the patients with stable fractures and unstable fractures separately to screen the independent risk factors of internal fixation-related complications.Results:For the patients with stable fractures, the univariate analysis indicated significant differences in bone density and reduction quality between the complication group and non-complication group ( P<0.05 or 0.01); the multivariate Logistic regression analysis showed that bone density T value ≤-3.0 SD ( OR=33.17, 95% CI 2.40, 457.82, P<0.01) and poor reduction quality ( OR=71.38, 95% CI 3.58, 1 422.02, P<0.01) were significantly correlated with the incidence of the postoperative complications. For the patients with unstable fractures, the univariate analysis indicated significant differences in age, reduction quality, bone density, tip-apex distance, and screw displacement between the complication group and non-complication group ( P<0.05 or 0.01); the multivariate Logistic regression analysis showed that age >80 years ( OR=2.82, 95% CI 1.01, 7.93, P<0.05), bone density T value ≤-3.0 SD ( OR=6.10, 95% CI 2.06, 17.51, P<0.01), poor reduction quality ( OR=12.25, 95% CI 2.90, 51.79, P<0.01), tip-apex distance ≥25 mm ( OR=3.65, 95% CI 1.20, 11.08, P<0.05), and head screw displacement <4 mm ( OR=7.26, 95% CI 2.54, 20.81, P<0.01) were significantly correlated with the postoperative complications. Conclusion:For Inter-Tan intramedullary nail fixation of intertrochanteric fractures in elderly patients, low bone density and poor reduction quality are independent risk factors for the postoperative complications in patients with stable intertrochanteric fractures; old age, low bone density, poor reduction quality, tip-apex distance, and head screw displacement are independent risk factors for the postoperative complications in patients with unstable fractures.

Objective:To explore the risk factors for heart failure after hip fracture surgery in the elderly patients and the impact of heart failure on their prognosis.Methods:A retrospective study was conducted to analyze the data of 1,478 elderly patients with hip fracture who had been admitted to The 7th Medical Center, General Hospital of the Chinese People's Liberation Army from January 2012 to December 2019. There were 482 males and 996 females with an age of 81 (75, 90) years. The patients were divided into a failure group and a failure-free group based on whether they had experienced any heart failure during postoperative hospitalization. After the clinical data were compared between the 2 groups, the variables with P<0.05 were included in the following multivariate logistic regression analysis to determine the risk factors for postoperative heart failure in the elderly patients with hip fracture. The mortality rates at 30 days and 1 year after operation, hospital stay, and incidence of postoperative complications were compared between the 2 groups. Results:Postoperative heart failure occurred in 7.0% (104/1,478) of the patients. The multivariate logistic regression analysis showed that advanced age ( OR=1.035, 95% CI: 1.006 to 1.065, P=0.018), male ( OR=1.727, 95% CI: 1.125 to 2.651, P=0.012), arrhythmia ( OR=1.830, 95% CI: 1.104 to 3.031, P=0.019), a high volume of blood transfusion ( OR=1.100, 95% CI: 1.001 to 1.209, P=0.048), and preoperative use of anticoagulant or antiplatelet drugs ( OR=1.921, 95% CI: 1.053 to 3.505, P=0.033) were risk factors for postoperative heart failure in the elderly patients with hip fracture. In the failure group, the mortality rates at 30 days and 1 year after operation were 9.6% (10/104) and 22.1% (23/104), and the incidence of postoperative complications was 32.7% (34/104), all significantly higher than those in the failure-free group [3.6% (49/1,374), 13.8% (190/1,374), and 17.5% (241/1,374)] ( P<0.05). The hospitalization time for the failure group was 14 (11, 19) days, significantly longer than that for the failure-free group [11 (9, 15) days] ( P<0.05). Conclusions:Advanced age, male, arrhythmia, a high volume of blood transfusion, and preoperative use of anticoagulant or antiplatelet drugs are risk factors for heart failure in the elderly patients after hip fracture surgery. Patients with heart failure may face poor prognosis, a high mortality rate, multiple complications, and long hospital stay.

Objective:To compare the failure risks between restricted and unrestricted cephalomedullary nail sliding during InterTAN intramedullary nail fixation for intertrochanteric fractures in the elderly patients.Methods:A retrospective study was conducted to analyze the data of 192 elderly patients with intertrochanteric fracture who had been admitted to Department of Orthopaedics, The Seventh Medical Center, General Hospital of the People's Liberation Army from January 2021 to December 2022. The patients were divided into 2 groups based on whether the set screws were tightened or not during surgery. In the observation group of 78 cases, there were 31 males and 47 females with an age of (80.2±7.7) years, and 23 cases of type 31-A1 and 55 cases of type 31-A2 by the AO classification. Their set screws were not tightened during surgery to allow the cephalomedullary nail sliding. In the control group of 114 cases, there were 40 males and 74 females with an age of (81.6±7.8) years, and 42 cases of type 31-A1 and 72 cases of type 31-A2. Their set screws were tightened during surgery to restrict the cephalomedullary nail sliding. The incidence of postoperative fixation complications and sliding distances of the cephalomedullary nail within 1 year after surgery were compared between the 2 groups in the total fractures and in the stable and unstable fractures as well.Results:There was no statistically significant difference in the preoperative general data between the 2 groups of patients, indicating comparability ( P>0.05). The incidence of fixation complications within 1 year after surgery was 5.1% (4/78) for the observation group and 12.3% (14/114) for the control group, showing no statistically significant difference between the 2 groups ( P>0.05). The sliding distance of the cephalomedullary nail in the observation group [7.05 (6.00, 8.25) mm] was significantly larger than that in the control group [5.65 (3.55, 7.00) mm] ( P<0.05). For stable fractures, the incidence of fixation complications within 1 year after surgery was 7.1% (2/28) for the observation group and 7.0% (3/43) for the control group, showing no statistically significant difference ( P>0.05), and the sliding distance of the cephalomedullary nail in the observation group [6.00 (5.25, 7.00) mm] was significantly greater than that in the control group [3.05 (2.00, 5.00) mm] ( P<0.05). For unstable fractures, the incidence of fixation complications within 1 year after surgery for the observation group patients [4.0% (2/50)] was significantly lower than that for the control group patients [15.5% (11/71)], and the sliding distance of the cephalomedullary nail in the observation group [8.00 (6.70, 10.00) mm] was significantly greater than that in the control group [6.00 (4.87, 7.57) mm] ( P<0.05). Conclusions:In the InterTAN intramedullary nail fixation for intertrochanteric fractures in the elderly patients, tightening of set screws is crucial because it not only increases the stability but also limits compression at the fracture site. It is recommended not to tighten the set screws for unstable fractures, but further observation is needed before it can be determined whether the set screws should be tightened or not for stable fractures.