Objective:To investigate how age and nail-tract volumetric bone mineral density (vBMD) are associated with postoperative mechanical performance of proximal femoral nail anti-rotation (PFNA-Ⅱ) fixation for geriatric intertrochanteric fractures using a finite-element analysis.Methods:Fifteen elderly patients with intertrochanteric fracture of the femur were selected for this study. They were 11 females and 4 males and divided into 5 groups based on their ages ( n=3): 55-year-old, 65-year-old, 75-year-old, 85-year-old, and 95-year-old groups. After three-dimensional models of the proximal femur were constructed using the preoperative CT data of their healthy contralateral hip, 31-A1.2 fractures of the AO/OTA type were created and PFNA-Ⅱ fixations simulated. Two loading schemes were created: graded quasi-static axial loads (700 N, 1,400 N, 2,100 N, and 2,800 N) were applied to compute equivalent plastic strain volumes in the femoral head region; displacement-controlled loading was applied to failure to derive load-displacement curves for stiffness and the maximum failure load. Nail-tract vBMD and regional hip vBMDs were measured by quantitative CT. Pearson correlation analysis was conducted to investigate the associations of age and nail-tract vBMD with the aforementioned mechanical indicators. Results:Under the same load, compared with the 55-year-old, 65-year-old, and 75-year-old groups, the plastic strain unit volumes of the fracture models in the 85-year-old and 95-year-old groups increased significantly. Under a load of 700 N, no plastic strain was observed in the fracture models in the 55-year-old, 65-year-old, and 75-year-old groups, while an average plastic strain of approximately 50 mm 3 was observed in the fracture models in the 85-year-old group. Under a load of 2,800 N, the high strain areas in the fracture models in the 85-year-old and 95-year-old groups were mainly concentrated at the tip of the head nail and the junction between the head nail and the main nail. Load-displacement curves showed a marked reduction in the failure load in patients aged ≥85 years. Under loads of 1,400 N, 2,100 N, and 2,800 N, there was a strong association between the nail-tract vBMD and the volume of the plastic strain unit ( r=-0.82, -0.88, -0.89, respectively), which was stronger than those for total-hip vBMD. Conclusions:Finite-element analysis indicates that age and nail-tract vBMD are closely related to local plastic strain and overall stiffness of the proximal femur after PFNA-Ⅱ fixation for the geriatric intertrochanteric fractures. Patients aged ≥85 years old are more prone to plastic yielding, which compromises fixation stability.

Objective:To investigate the association between quantitative CT-derived hip bone mineral density (BMD) and all-cause mortality in elderly women after hip fracture surgery.Methods:A retrospective study was conducted to analyze the clinical data of the 254 elderly women with hip fracture who had been surgically treated at Department of Orthopaedics and Traumatology, Shunyi District Hospital between December 2018 and December 2019. Their average age was (79.3±7.7) years. There were 128 femoral neck fractures and 126 intertrochanteric fractures. CT images of their proximal femurs on the healthy side were analyzed using quantitative CT Pro software to assess the BMDs at the femoral neck, greater trochanter, intertrochanteric region, and total hip. The primary endpoint was all-cause mortality during follow-up. The patients were classified into a death group and a censored group (survivors and those lost to follow-up). The secondary outcome was recovery of pre-fracture ambulation. Multivariable Cox proportional hazards regression was performed to evaluate the association between regional hip BMD and mortality risk.Results:Of the patients, 236 obtained a follow-up of 36.9 (32.7, 42.6) months and 18 were lost to the follow-up. A total of 28.3% (72/254) of the patients died within 3 years after surgery. The overall hip BMD [(0.510 9±0.094 3) g/cm 2], the greater trochanter BMD [(0.351 0±0.079 6) g/cm 2], and the intertrochanteric BMD[(0.629 5±0.116 9) g/cm 2] in the death group were significantly lower than those in the censored group [(0.565 8±0.104 1) g/cm 2, (0.398 6±0.092 1) g/cm 2, and (0.685 6±0.126 6) g/cm 2]( P<0.05). The multivariate Cox regression analysis showed that a lower BMD at all hip sites measured was significantly associated with a higher mortality risk before adjustments ( P<0.05), but after confounding variables were adjusted, only the greater trochanter BMD ( HR=1.789, 95% CI: 1.035 to 3.092, P=0.037) and the intertrochanteric BMD ( HR=1.758, 95% CI: 1.018 to 3.037, P=0.043) were significantly associated with a higher mortality risk. Furthermore, follow-ups showed that 54 patients (56.3%, 54/96) in the high trochanter BMD group regained their pre-fracture ambulatory status, significantly more than the 22 patients in the low BMD group (32.4%, 22/68), showing an increased odds of ambulation recovery ( OR=2.688, 95% CI: 1.405 to 5.143, P=0.003). Conclusion:In elderly women with hip fracture, quantitative CT-derived measurement of the hip BMD, particularly in the trochanteric region, can serve as an early warning indicator of all-cause mortality after hip fracture surgery.

Postoperative infection of internal fixation of closed fractures the lower limbs in adults represents a devastating complication, characterized by diagnostic challenges, prolonged treatment duration and high disability rates. Current management of these infections faces multiple challenges, such as difficulties in early accurate diagnosis, and various controversies about the treatment plan, leading to poor overall diagnosis and treatment results. To address these issues, based on evidence-based medicine and principles with emphasis on scientific rigor, clinical applicability and innovation, the Trauma Branch of the Chinese Medical Association, Orthopedic Branch of the Chinese Medical Doctor Association, Orthopedics Branch of the Chinese Medical Association, and Trauma Orthopedics and Polytrauma Group of the Resuscitation and Emergency Committee of the Chinese Medical Doctor Association have collaboratively organized a panel of relevant experts to develop the Guideline for diagnosis and treatment of infection after internal fixation of closed lower limb fractures in adults ( version 2025). The guideline proposed 10 recommendations, aiming to provide a foundation for standardized diagnosis and treatment of postoperative infection in adults with closed lower limb fractures.

Objective To explore the protective effect of 7,8-dihydroxyflavone(7,8-DHF)on the retina of diabetic rats and its mechanism.Methods A total of 18 SPF-grade male Sprague-Dawley(SD)rats were selected and randomly divided into three groups:the normal group,the model group,and the experimental group,with six rats in each group.Rats in the normal group were fed with a normal diet,while those in the remaining two groups were fed with a high-fat emulsion through oral gavage continuously for 2 weeks to establish a diabetes model.Rats in the experimental group were provided with 7,8-DHF(5 mg?kg-1)by continuous intraperitoneal injection,while those in the normal and model groups were provided with an equal volume of normal saline.The rats in all groups received intervention once a day for 2 weeks.The changes in the body mass and fasting blood glucose(FBG)were observed before and after modeling.Besides,the changes in the retina of rats in each group were observed by fundus fluorescence angiography(FFA)after 2 weeks.Moreo-ver,the changes and apoptosis of retinal neuronal cells were detected by hematoxylin and eosin(HE)staining,CD31 im-munofluorescence,and terminal deoxynucleotidyl transferase dUTP nick end labeling(TUNEL)assays.Results After 2 weeks of continuous intervention,compared with the normal group,the body mass of rats in the model and experimental groups decreased(both P＜0.05),and the FBG increased significantly(both P＜0.05);compared with the model group,the experimental group showed an increase in the body mass(P＜0.05)and a decrease in the FBG(P＜0.05).The fundus photography and FFA of rats in the three groups did not reveal any fundus features of diabetic retinopathy.The HE staining results showed that the retina of rats in the normal and experimental groups was structurally intact,with neatly arranged cells and uniform thickness;the retinal structure of rats in the model group remained clear.However,the thickness of the inner layers of the retina of rats in the model group was thinner compared with the normal and experimental groups,exhibi-ting significant differences(both P＜0.05).The CD31 immunofluorescence assay results indicated that the CD31 immuno-fluorescence intensity values of rats in the three groups were roughly comparable,without significant differences(all P＞0.05).The TUNEL assay results suggested that the apoptosis of retinal neurons increased in rats in the model group com-pared with the normal group,exhibiting significant differences(P＜0.001);compared with the model group,the apoptosis of retinal neurons of rats in the experimental group decreased significantly,displaying significant differences(P＜0.001).Conclusion The apoptosis of retinal neurons in diabetic rats may precede vascular endothelial cell injury.7,8-DHF can improve the body mass,decrease the blood glucose level,and protect the retinal neurons in diabetic rats.

Postoperative infection of internal fixation of closed fractures the lower limbs in adults represents a devastating complication, characterized by diagnostic challenges, prolonged treatment duration and high disability rates. Current management of these infections faces multiple challenges, such as difficulties in early accurate diagnosis, and various controversies about the treatment plan, leading to poor overall diagnosis and treatment results. To address these issues, based on evidence-based medicine and principles with emphasis on scientific rigor, clinical applicability and innovation, the Trauma Branch of the Chinese Medical Association, Orthopedic Branch of the Chinese Medical Doctor Association, Orthopedics Branch of the Chinese Medical Association, and Trauma Orthopedics and Polytrauma Group of the Resuscitation and Emergency Committee of the Chinese Medical Doctor Association have collaboratively organized a panel of relevant experts to develop the Guideline for diagnosis and treatment of infection after internal fixation of closed lower limb fractures in adults ( version 2025). The guideline proposed 10 recommendations, aiming to provide a foundation for standardized diagnosis and treatment of postoperative infection in adults with closed lower limb fractures.

Objective:To investigate how age and nail-tract volumetric bone mineral density (vBMD) are associated with postoperative mechanical performance of proximal femoral nail anti-rotation (PFNA-Ⅱ) fixation for geriatric intertrochanteric fractures using a finite-element analysis.Methods:Fifteen elderly patients with intertrochanteric fracture of the femur were selected for this study. They were 11 females and 4 males and divided into 5 groups based on their ages ( n=3): 55-year-old, 65-year-old, 75-year-old, 85-year-old, and 95-year-old groups. After three-dimensional models of the proximal femur were constructed using the preoperative CT data of their healthy contralateral hip, 31-A1.2 fractures of the AO/OTA type were created and PFNA-Ⅱ fixations simulated. Two loading schemes were created: graded quasi-static axial loads (700 N, 1,400 N, 2,100 N, and 2,800 N) were applied to compute equivalent plastic strain volumes in the femoral head region; displacement-controlled loading was applied to failure to derive load-displacement curves for stiffness and the maximum failure load. Nail-tract vBMD and regional hip vBMDs were measured by quantitative CT. Pearson correlation analysis was conducted to investigate the associations of age and nail-tract vBMD with the aforementioned mechanical indicators. Results:Under the same load, compared with the 55-year-old, 65-year-old, and 75-year-old groups, the plastic strain unit volumes of the fracture models in the 85-year-old and 95-year-old groups increased significantly. Under a load of 700 N, no plastic strain was observed in the fracture models in the 55-year-old, 65-year-old, and 75-year-old groups, while an average plastic strain of approximately 50 mm 3 was observed in the fracture models in the 85-year-old group. Under a load of 2,800 N, the high strain areas in the fracture models in the 85-year-old and 95-year-old groups were mainly concentrated at the tip of the head nail and the junction between the head nail and the main nail. Load-displacement curves showed a marked reduction in the failure load in patients aged ≥85 years. Under loads of 1,400 N, 2,100 N, and 2,800 N, there was a strong association between the nail-tract vBMD and the volume of the plastic strain unit ( r=-0.82, -0.88, -0.89, respectively), which was stronger than those for total-hip vBMD. Conclusions:Finite-element analysis indicates that age and nail-tract vBMD are closely related to local plastic strain and overall stiffness of the proximal femur after PFNA-Ⅱ fixation for the geriatric intertrochanteric fractures. Patients aged ≥85 years old are more prone to plastic yielding, which compromises fixation stability.

Objective:To investigate the association between quantitative CT-derived hip bone mineral density (BMD) and all-cause mortality in elderly women after hip fracture surgery.Methods:A retrospective study was conducted to analyze the clinical data of the 254 elderly women with hip fracture who had been surgically treated at Department of Orthopaedics and Traumatology, Shunyi District Hospital between December 2018 and December 2019. Their average age was (79.3±7.7) years. There were 128 femoral neck fractures and 126 intertrochanteric fractures. CT images of their proximal femurs on the healthy side were analyzed using quantitative CT Pro software to assess the BMDs at the femoral neck, greater trochanter, intertrochanteric region, and total hip. The primary endpoint was all-cause mortality during follow-up. The patients were classified into a death group and a censored group (survivors and those lost to follow-up). The secondary outcome was recovery of pre-fracture ambulation. Multivariable Cox proportional hazards regression was performed to evaluate the association between regional hip BMD and mortality risk.Results:Of the patients, 236 obtained a follow-up of 36.9 (32.7, 42.6) months and 18 were lost to the follow-up. A total of 28.3% (72/254) of the patients died within 3 years after surgery. The overall hip BMD [(0.510 9±0.094 3) g/cm 2], the greater trochanter BMD [(0.351 0±0.079 6) g/cm 2], and the intertrochanteric BMD[(0.629 5±0.116 9) g/cm 2] in the death group were significantly lower than those in the censored group [(0.565 8±0.104 1) g/cm 2, (0.398 6±0.092 1) g/cm 2, and (0.685 6±0.126 6) g/cm 2]( P<0.05). The multivariate Cox regression analysis showed that a lower BMD at all hip sites measured was significantly associated with a higher mortality risk before adjustments ( P<0.05), but after confounding variables were adjusted, only the greater trochanter BMD ( HR=1.789, 95% CI: 1.035 to 3.092, P=0.037) and the intertrochanteric BMD ( HR=1.758, 95% CI: 1.018 to 3.037, P=0.043) were significantly associated with a higher mortality risk. Furthermore, follow-ups showed that 54 patients (56.3%, 54/96) in the high trochanter BMD group regained their pre-fracture ambulatory status, significantly more than the 22 patients in the low BMD group (32.4%, 22/68), showing an increased odds of ambulation recovery ( OR=2.688, 95% CI: 1.405 to 5.143, P=0.003). Conclusion:In elderly women with hip fracture, quantitative CT-derived measurement of the hip BMD, particularly in the trochanteric region, can serve as an early warning indicator of all-cause mortality after hip fracture surgery.

Objective To explore the protective effect of 7,8-dihydroxyflavone(7,8-DHF)on the retina of diabetic rats and its mechanism.Methods A total of 18 SPF-grade male Sprague-Dawley(SD)rats were selected and randomly divided into three groups:the normal group,the model group,and the experimental group,with six rats in each group.Rats in the normal group were fed with a normal diet,while those in the remaining two groups were fed with a high-fat emulsion through oral gavage continuously for 2 weeks to establish a diabetes model.Rats in the experimental group were provided with 7,8-DHF(5 mg?kg-1)by continuous intraperitoneal injection,while those in the normal and model groups were provided with an equal volume of normal saline.The rats in all groups received intervention once a day for 2 weeks.The changes in the body mass and fasting blood glucose(FBG)were observed before and after modeling.Besides,the changes in the retina of rats in each group were observed by fundus fluorescence angiography(FFA)after 2 weeks.Moreo-ver,the changes and apoptosis of retinal neuronal cells were detected by hematoxylin and eosin(HE)staining,CD31 im-munofluorescence,and terminal deoxynucleotidyl transferase dUTP nick end labeling(TUNEL)assays.Results After 2 weeks of continuous intervention,compared with the normal group,the body mass of rats in the model and experimental groups decreased(both P＜0.05),and the FBG increased significantly(both P＜0.05);compared with the model group,the experimental group showed an increase in the body mass(P＜0.05)and a decrease in the FBG(P＜0.05).The fundus photography and FFA of rats in the three groups did not reveal any fundus features of diabetic retinopathy.The HE staining results showed that the retina of rats in the normal and experimental groups was structurally intact,with neatly arranged cells and uniform thickness;the retinal structure of rats in the model group remained clear.However,the thickness of the inner layers of the retina of rats in the model group was thinner compared with the normal and experimental groups,exhibi-ting significant differences(both P＜0.05).The CD31 immunofluorescence assay results indicated that the CD31 immuno-fluorescence intensity values of rats in the three groups were roughly comparable,without significant differences(all P＞0.05).The TUNEL assay results suggested that the apoptosis of retinal neurons increased in rats in the model group com-pared with the normal group,exhibiting significant differences(P＜0.001);compared with the model group,the apoptosis of retinal neurons of rats in the experimental group decreased significantly,displaying significant differences(P＜0.001).Conclusion The apoptosis of retinal neurons in diabetic rats may precede vascular endothelial cell injury.7,8-DHF can improve the body mass,decrease the blood glucose level,and protect the retinal neurons in diabetic rats.

Radical cystectomy combined with pelvic lymph node dissection is the standard procedure for the treatment of muscle invasive bladder cancer and complex non-muscle invasive bladder cancer.Our department has routinely carried out laparoscopic radical cystectomy(ELRC)through the extraperitoneal approach in 340 cases.This article summarizes the establishment of the peritoneal space,the expansion of the peritoneal space,the operation steps of bladder resection and lymph node dissection through the peritoneal channel,and how to shorten the operation time and reduce the difficulty of the operation.During the surgery,the bladder is removed periperitoneally without destroying the peritoneum to preserve the functions of peritoneum support,secretion,protection and lubrication,which has little impact on the abdominal organs,reduces the incidence of complications,and provides favorable conditions for subsequent treatment.

Objective To explore the therapeutic effect of mesorectal excision in gasless transaxillary endoscopic thyroidectomy.Methods Clinical data of 75 patients who underwent gasless unilateral transaxillary endoscopic thyroidectomy from May 2020 to November 2022 were retrospectively analyzed.A total of 40 cases were treated with mesorectal excision(observation group),and 35 cases were treated with thyroid resection followed with central lymph node resection(control group).The operation time,intraoperative blood loss,postoperative hospital stay,number of lymph nodes dissected,and postoperative complications were compared between the two groups.Results All the patients successfully completed the operation.As compared with the control group,the observation group had shorter operation time[(91.8±19.7)min vs.(110.4±19.3)min,t =-4.133,P =0.000]and more lymph nodes dissected[(6.5±2.5)vs.(4.6±2.0),t = 3.610,P = 0.001].There were no statistically significant differences between the two groups in the amount of intraoperative bleeding,recurrent laryngeal nerve injury,and the postoperative hospital stay.There was no hypoparathyroidism,postoperative bleeding,or wound infection in both groups.Conclusion Mesorectal excision is safe and feasible in endoscopic thyroidectomy via axillary approach,with more thorough lymph node dissection in the central region and better protection of recurrent laryngeal nerve.