BACKGROUND:With the development of the aging trend of society,the incidence of femoral neck fractures is increasing.Currently,the preferred surgical treatment is cannulated screw internal fixation.However,post-surgical femoral neck shortening occurs in some cases,resulting in impaired hip functionality.OBJECTIVE:To investigate the incidence of femoral neck shortening following the use of half-threaded cannulated screws for internal fixation in patients with femoral neck fractures,to analyze the effect on hip function,and to identify factors contributing to neck shortening.METHODS:A retrospective analysis was conducted on the medical records of 102 patients treated with half-threaded cannulated screws in an inverted triangle setup for femoral neck fractures at Affiliated Hai'an Hospital of Nantong University from January 2016 to January 2021.This group included 36 males and 66 females at the mean age of(57.2±7.7)years,with 34 cases of Garden type Ⅰ and Ⅱ fractures and 68 of Garden type Ⅲ and Ⅳ fractures.The mean bone mineral density value T was-2.8 SD.The Harris score was used to evaluate the hip function.During the follow-up period,the occurrence of femoral neck shortening was determined using X-ray imagery,and the factors influencing this shortening were examined using both univariate and multivariate regression analyses.RESULTS AND CONCLUSION:(1)Among the 102 patients with femoral neck fractures,30 patients developed femoral neck shortening,accounting for 29.4％.72 patients had no femoral neck shortening(70.6％).(2)The Harris score for patients experiencing neck shortening was significantly lower than that for patients without shortening(P＜0.05).(3)The study identified several factors associated with femoral neck shortening following the internal fixation of femoral neck fractures included age,gender,bone mineral density value T,preoperative Garden classification,and quality of reduction.These factors not only affect the shortening of the femoral neck after surgery,but are also directly related to the functional performance of the patient's hip joint.(4)Femoral neck shortening after surgery for femoral neck fracture is associated with various clinical parameters,especially the patient's age,gender,bone mineral density,preoperative classification,and accuracy of reduction during surgery.

BACKGROUND:With the development of the aging trend of society,the incidence of femoral neck fractures is increasing.Currently,the preferred surgical treatment is cannulated screw internal fixation.However,post-surgical femoral neck shortening occurs in some cases,resulting in impaired hip functionality.OBJECTIVE:To investigate the incidence of femoral neck shortening following the use of half-threaded cannulated screws for internal fixation in patients with femoral neck fractures,to analyze the effect on hip function,and to identify factors contributing to neck shortening.METHODS:A retrospective analysis was conducted on the medical records of 102 patients treated with half-threaded cannulated screws in an inverted triangle setup for femoral neck fractures at Affiliated Hai'an Hospital of Nantong University from January 2016 to January 2021.This group included 36 males and 66 females at the mean age of(57.2±7.7)years,with 34 cases of Garden type Ⅰ and Ⅱ fractures and 68 of Garden type Ⅲ and Ⅳ fractures.The mean bone mineral density value T was-2.8 SD.The Harris score was used to evaluate the hip function.During the follow-up period,the occurrence of femoral neck shortening was determined using X-ray imagery,and the factors influencing this shortening were examined using both univariate and multivariate regression analyses.RESULTS AND CONCLUSION:(1)Among the 102 patients with femoral neck fractures,30 patients developed femoral neck shortening,accounting for 29.4％.72 patients had no femoral neck shortening(70.6％).(2)The Harris score for patients experiencing neck shortening was significantly lower than that for patients without shortening(P＜0.05).(3)The study identified several factors associated with femoral neck shortening following the internal fixation of femoral neck fractures included age,gender,bone mineral density value T,preoperative Garden classification,and quality of reduction.These factors not only affect the shortening of the femoral neck after surgery,but are also directly related to the functional performance of the patient's hip joint.(4)Femoral neck shortening after surgery for femoral neck fracture is associated with various clinical parameters,especially the patient's age,gender,bone mineral density,preoperative classification,and accuracy of reduction during 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.

Human naïve pluripotent stem cells (PSCs) hold great promise for embryonic development studies. Existing induction and culture strategies for these cells, heavily dependent on MEK inhibitors, lead to widespread DNA hypomethylation, aberrant imprinting loss, and genomic instability during extended culture. Here, employing high-content analysis alongside a bifluorescence reporter system indicative of human naïve pluripotency, we screened over 1,600 chemicals and identified seven promising candidates. From these, we developed four optimized media-LAY, LADY, LUDY, and LKPY-that effectively induce and sustain PSCs in the naïve state. Notably, cells reset or cultured in these media, especially in the LAY system, demonstrate improved genome-wide DNA methylation status closely resembling that of pre-implantation counterparts, with partially restored imprinting and significantly enhanced genomic stability. Overall, our study contributes advancements to naïve pluripotency induction and long-term maintenance, providing insights for further applications of naïve PSCs.
Humans ; DNA Methylation/drug effects* ; Genomic Instability ; Pluripotent Stem Cells/metabolism* ; Cell Culture Techniques/methods* ; Cells, Cultured

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.

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 clinical efficacy of disc repositioning surgery combined with orthodontic treatment in patients with temporomandibular disorder and facial asymmetry.Methods One patient who underwent disc repositioning surgery combined with orthodontic treatment for temporomandibular joint disorder and facial asymme-try was reported.Preoperatively,the patient had a skewed shape of the opening,mild pressure pain in the right preauric-ular region with left mandibular deviation,and a mismatch between the width of the upper and lower dental arches.In the arthrosurgery department,bilateral temporomandibular disc replacement and anchorage were performed through a transauricular incision,and an auxiliary splint was worn to stabilize the jaw position for 6 months.In the orthopedic de-partment,maxillary skeletal expansion was used in combination with the multiloop edgewise archwire technique to re-construct the occlusion after 16 months of orthodontic treatment.Results The deviation was corrected by wearing an occlusal splint for six months after joint repositioning and anchoring;moreover,the pain symptoms disappeared,and the cone beam CT examination showed that the bilateral temporomandibular joint space was uniformly enlarged,the lower alveolar ridge midline deviated to the right,the posterior regions of the teeth were bilaterally inverted,and the anterior region and the posterior region of the left side were open.The orthodontic treatment matched the width of the upper and lower dental arches and established the cuspal molar neutrality relationship and the normal overjet coverage of the ante-rior teeth;additionally,the mandibular position was not obviously skewed.A review of the results of the related litera-ture shows that abnormal occlusal relationships,such as mismatched arch width and skewed occlusal plane,can cause adaptive mandibular deviation,which can lead to the occurrence of TMD.Temporomandibular joint disc anchorage with splint treatment can effectively improve maxillofacial deformity in young TMD patients.After the establishment of a sta-ble,physiologically functional disc-condylar relationship,orthodontic treatment is required to remove the interfering fac-tors to rebuild the occlusion,and long-term postoperative review and follow-up are needed.Conclusion In patients with TMD and mandibular accommodative deviation due to occlusal anomalies,establishing a normal disc-condylar rela-tionship and eliminating occlusal interference through disc repositioning surgery combined with orthodontic treatment can effectively improve facial shape and establish a stable jaw position.

Objective:To explore the correlation between hip muscle factors measured with CT imaging and recovery of independent mobility within 1 year after surgery in elderly patients with hip fractures.Methods:A prospective cohort study was conducted on the clinical data of 680 elderly patients with hip fractures admitted to Beijing Jishuitan Hospital of Capital Medical University from November 2018 to December 2019. The patients were assigned to dependent group and assistant group according to whether they regained pre-injury independent mobility within 1 year after surgery. Gender, age, body mass index, personal history, living habits, past diseases, Charlson comorbidity index, laboratory test indicators, fracture types, anesthesia types, surgical methods, rehabilitation training, time from injury to surgery, and hip muscle parameters in both groups were recorded. OsiriX software was employed in the measurement of the hip muscles to measure the muscle area and density of the gluteus maximus and gluteus medius/minimus on CT images, and the average values were calculated as hip muscle area and density. Then the variables of hip muscle area and density were converted seperately to gender-normalized Z-scores, and were divided into high-area group ( Z≥0) and low-area group ( Z<0), and high-density group ( Z≥0) and low-density group ( Z<0) respectively. Observable variables were primarily analyzed using univariate analysis between the independent group and assistant group. Those variables with statistically significant differences in the univariate analysis or would potentially affect mobility recovery according to previous researches although there were no statistical significance were included in a multivariate Logistic regression analysis. Three Logistic regression models were designed (Model 1 uncorrected, Model 2 corrected for gender, age and body mass index, Model 3 corrected for variables in Model 2 and other variables included after above-mentioned analysis) to analyze whether muscle parameters were risk factors for recovery of independent mobility. Additionally, generalized estimating equations were used for repeated measurement to analyze the correlation between hip muscle area and recovery of independent mobility after surgery. Results:Compared to the assistant group, the independent group were younger in age, with lower rate of living alone, being housebound, cognitive impairment, and Charlson comorbidity index, lower level of hemoglobin and albumin, higher rate of femoral neck fractures, lower rate of internal fixation, shorter time from injury to surgery, larger hip muscle area, and higher hip muscle density ( P<0.05 or 0.01). Multivariate Logistic regression analysis showed that, in the fully corrected Model 3, only hip muscle area remained significantly correlated with recovery of independent mobility ( P<0.05), while no significant difference was found between the high-density group and low-density group ( P>0.05). In the repeated measurement, patients in the high-area group were 1.84 times more likely to restore independent mobility than those in the low-area group ( OR=1.84, 95% CI 1.33, 2.53, P<0.01). Conclusions:Hip muscle area measured with CT imaging is closely correlated to the recovery of independent mobility within 1 year after surgery in elderly patients with hip fractures. Moreover, larger hip muscle area indicates a larger likelihood of recovery of independent mobility.

Objective To explore the clinical effect of personalized pars plana vitrectomy(PPV)for proliferative di-abetic retinopathy(PDR).Methods In this retrospective case study,76 patients(86 eyes)diagnosed with PDR and re-ceiving PPV in the Department of Ophthalmology of Songjiang Hospital affiliated to Shanghai Jiao Tong University School of Medicine,from October 2019 to November 2022,were divided into the observation group(40 patients,46 eyes)and the control group(36 patients,40 eyes).Patients in the obseration group were treated with personalized PPV,while patients in the control group were treated with conventional PPV,After treatment,all patients were followed up for 12 months.The operation time,intraoperative use of heavy water and silicone oil,incidence of iatrogenic retinal tears and heavy water resi-dues,proportion of scleral buckling,preoperative and postoperative best corrected visual acuity(BCVA)and intraocular pressure(IOP),retinal reattachment rate at 12 months after surgery,and the incidence of post-vitrectomy vitreous hemor-rhage(PVH),diabetic macular edema(DME)and neovascular glaucoma(NVG)were compared between the two groups.Results The operation time of patients in the observation group was shorter than that in the control group(P＜0.05).Intraoperative use of heavy water and silicone oil in the observation group was lower than that in the control group(both P＜0.05).The incidence of iatrogenic retinal tears and heavy water residues and the proportion of scleral buckling showed no statistically significant difference between the two groups(all P＞0.05).There was no statistically significant difference between the two groups in BCVA preoperatively,3,6 and 12 months postoperatively(all P＞0.05).BCVA in the observa-tion group was better than that in the control group at 1 day,1 week and 1 month after surgery(all P＜0.05).Compared with the preoperative value,BCVA increased in the observation group at 1 day,1 week,1 month,3 months,6 months,and 12 months after surgery(all P＜0.05);in the control group,BCVA increased slightly at 1 day and 1 week(both P＞0.05)and then increased significantly at 1 month,3 months,6 months,and 12 months after surgery(all P＜0.05).The two groups showed no statistically significant difference in IOP at 1 day,1 week,1 month,3 months,6 months,and 12 months postoperatively(all P＞0.05).There was no statistically significant difference in the retinal reattachment rate and the inci-dence of complications such as PVH,DME,and NVG between the two groups at 12 months postoperatively(all P＞0.05).Conclusion Personalized PPV can shorten the operation time,reduce the intraoperative use of heavy water and silicone oil,enhance the efficiency of the operation,and rapidly improve the visual acuity of PDR patients.