To compare the effects of advanced bone flap and no bone flap on the healing of osteotomy gap in open-wedge high tibial osteotomy (OW-HTO) for the treatment of medial compartment osteoarthritis and knee inversion.Methods:A retrospective study was conducted to analyze the 85 patients who had undergone OW-HTO from March 2021 to December 2021 at Trauma Emergency Centre, The Third Hospital of Hebei Medical University for medial compartment osteoarthritis and knee inversion. The patients were divided into 2 groups according to whether bone flap was grafted. In group A of 42 patients who received advanced bone flap intraoperatively, there were 32 females and 10 males with an age of (63.7±6.6) years; in group B of 43 patients who received no advanced bone flap intraoperatively, there were 31 females and 12 males with an age of (63.2±9.4) years. The measures recorded and compared between the 2 groups included: osteotomy gap healing rates at 3, 6, 12, and 18 months postoperatively; Western Ontario and McMaster Universities Osteoarthritis Index (WOMAC), Visual Analog Scale (VAS) for pain, and Knee injury and Osteoarthritis Outcome Score (KOOS) at 6 and 18 months postoperatively; medial proximal tibial angle (MPTA) and femorotibial angle at immediate postoperation and 18 months postoperation; postoperative complications.Results:The differences in preoperative general information between the 2 groups were not statistically significant, showing comparability ( P>0.05). The osteotomy gap healing rates at 3, 6, 12, and 18 months postoperatively in group A were significantly higher than those in group B ( P<0.05). The WOMAC (26.1±5.9), VAS (4.1±1.4), and KOOS (47.0±9.7) scores at 6 months postoperatively in group A were significantly lower than those in group B (31.3±8.3, 4.8±1.6, and 56.1±11.9) ( P<0.05), but the differences in the above indicators between the 2 groups at 18 months postoperatively were not statistically significant ( P>0.05). There was no statistically significant difference in MPTA or femorotibial angle at immediate postoperation between the 2 groups ( P>0.05). At 18 months postoperatively, the MPTA in group A (88.7°±1.1°) was significantly better than that in group B (87.7°±1.5°) ( P<0.05). The total complication rate in group B [27.9% (12/43)] was signifcantly higher than that in group A [2.4% (1/42)]( P<0.05). Conclusions:In the OW-HTO treatment of the patients with medial compartment osteoarthritis and knee inversion, application of an advanced bone flap to fill the osteotomy gap can accelerate the gap healing and reduces occurrence of delayed healing or non-healing of the osteotomy gap.

Objective:To characterize the biomechanics of distal dynamic locking and distal static locking of proximal femur bionic nails (PFBN) in fixation of intertrochanteric fractures by a finite element analysis.Methods:The CT image data from the hip to the upper tibia from an adult male volunteer were used to establish a three-dimensional model of the femur by Mimics 20.0 and Geomagic 2013 which was processed further into a model of Evans type I intertrochanteric fracture by software NX 12.0. With reference to the internal fixation parameters commonly used, 4 models of PFBN fixation were established: distal single transverse nail dynamic locking (model A), single oblique nail dynamic locking (model B), single nail static locking (model C) and double nail dynamic locking (model D). Abaqus 6.14 software was used to load and analyze the internal fixation stresses and displacements of fracture ends.Results:Under a 2100N loading, the peak stress was located upon the main nail in the 4 models. The smallest peak stress upon the main nail was in Model D (161.9 MPa), decreased by 15.9% compared with model A (192.5 MPa), by 15.6% compared with model B (191.9 MPa), and by 0.9% compared with model C (163.3 MPa). The peak stress upon the fixation screw was the largest in model A (95.3 MPa), the smallest in model B (91.5 MPa), and 91.5 MPa and 92.2 MPa in models C and D, respectively. The overall displacements of the implants, in a descending order, were 10.14 mm in model A, 10.10 mm in model B, 10.09 mm in model C, and 10.05 mm in model D. Similarly, the displacements of fracture ends were 0.125 mm in model A, 0.121 mm in model B, 0.110 mm in model C, and 0.098 mm in model D.Conclusion:Compared with dynamic locking, distal static locking of PFBN provides a better mechanical stability and reduces stress concentration upon internal fixation.

Objective:To determine the relationship between tibial plateau stresses and malunion by exploring the changes in mechanical conduction in the knee joint after malunion of Hoffa fracture of the tibial plateau.Methods:This study selected 28 knee joint specimens treated with formalin for preservation, half of which were from male and half from female individuals with an age of (51.4±9.5) years. Their structures were intact, and flexion-extension activities normal. X-ray examinations excluded osteoporosis, tuberculosis, and diseases that could have potentially affected bone quality. The knee specimens were divided into a control group (intact tibia) ( n=4) and 6 groups of tibial plateau Hoffa fracture malunion model: 3 vertical malunion groups (groups V1, V2, and V3, with a vertical displacement of 1, 2, and 3 mm, respectively, n=4) and 3 separation malunion groups (groups S3, S5, and S7, with a separation displacement of 3, 5, and 7 mm, respectively), with half males and half females in each group. After a 600N vertical load was applied at passive knee flexions at 0°, 30°, 60°, 90°, and 120°, the stress levels in the medial and lateral compartments of the knee joint were measured using pressure-sensitive films. Results:Under a vertical load of 600 N, when the knee joint was in a neutral position (flexion of 0°), the differences in the medial and lateral tibial plateau stress values were not statistically significant between the malunion models groups and the control group ( P>0.05). When the knee flexion increased to 30°, the medial tibial plateau stress in the V3 and S7 groups was significantly greater than that in the control group ( P<0.05). At a knee flexion of 60°, the medial plateau stress was significantly greater in the V3, S5 and S7 groups than that in the control group, and the differences were significantly greater than the comparisons at a knee flexion of 30° (all P<0.05). When the knee flexion was 90°, the medial plateau stress in the V2, V3, S5 and S7 groups was significantly greater than that in the control group ( P<0.05), but the lateral tibial plateau stress in the V3 group was significantly smaller than that in the control group ( P<0.05). When the knee flexion was further increased to 120°, the differences in the medial and lateral plateau stress values were statistically significant between all the malunion groups and the control group ( P<0.05), and the differences significantly greater than the comparisons at a knee flexion of 90° (all P<0.05). Under a vertical load of 600 N, the differences in the stresses on the medial and lateral plateaus were not statistically significant between the control group and all the malunion groups at a knee flexion of 0° ( P>0.05). When the knee flexion increased to 30°, the difference between the medial and lateral stresses was not statistically significant in the control group ( P>0.05), but was statistically significant in the V3 and S7 groups ( P<0.05). When the knee flexion reached 60°, 90°, and 120°, the differences between the medial and lateral tibial plateau stresses in all the groups were statistically significant ( P<0.05). Conclusions:The peak knee stresses after malunion of Hoffa fracture of the tibial plateau correlate with the severity of malunion and knee flexion angles. The mechanical properties are not significantly different between a mild malunion knee and a normal knee, but a significant displacement (vertical displacement >2 mm and separation displacement ≥5 mm) may increase the peak knee stresses to increase the risk of knee osteoarthritis. When the severity of malunion is certain, an increase in knee flexion angle increases the difference in the peak stress between the medial and lateral tibial plateaus, thus increasing the risk of knee osteoarthritis.

【Objective】 To analyze the association of sexual development characteristics and phases with the cognitive and behavioral development of adolescents aged 10 to 14 in rural areas of Shaanxi Province, in order to provide scientific reference for enhancing adolescent health. 【Methods】 The study population was selected from a birth cohort study′s follow-up data for the adolescent phase. The Tanner quintile method was used to assess sexual development, the Wechsler Intelligence Scale for Children, Fourth Edition (WISC-Ⅳ) was used to assess cognitive development, and the Youth Self-Rating Scale(YSR-2001) was used to assess behavioral development. Generalized linear models was used to examine the association of the stages of adolescent sexual development with their cognitive and behavioral development. 【Results】 A total of 1 887 adolescents were enrolled in this study, with 1 111 (58.9%) boys. The proportion of boys and girls who have started sexual development was 78.22% and 89.30%, respectively. The detection rate of behavioral problems in adolescents was 9.70%, with 11.80% in boys and 6.70% in girls, and the gender difference was significant (χ²=13.517, P<0.001). Compared to adolescents in Tanner stage Ⅰ, adolescents in stage Ⅲ had a higher total cognitive score of 2.19 (95%CI: 0.15 - 4.23), and a higher total score of 3.84 (95%CI: 0.85 - 6.83,P<0.05) in stages Ⅳ-Ⅴ. The detection rate of total behavioral problems of children in Tanner stages Ⅳ-Ⅴ was 2.63 times (95%CI:1.27 - 5.46,P<0.05) higher than that in stage Ⅰ. In boys, the rate of detection of internalizing problems was 3.96 times(95%CI:1.60 - 9.81,P<0.01) higher than that in stage Ⅰ, and the detection rate of internalizing problems was 2.88 times(95%CI:1.19 - 7.01,P<0.05) higher than that in stage Ⅰ. 【Conclusions】 There is a significant correlation of sexual developmental phrase with cognitive and behavioral development among adolescents aged 10 - 14 years in rural Shaanxi Province. The detection rate of adolescent behavioral problems increases with the increase of sexual development level and cognitive level, and there are significant gender differences.

【Objective】 To explore the impact of intrapartum antibiotic prophylaxis (IAP) on antibiotic resistance genes (ARGs) in the gut microbiota of infants up to 6 months of age and their longitudinal changes, in order to provide theoretical basis for the rational use of antibiotics and antibiotic resistance control. 【Methods】 Fecal samples were collected within 3 days, 2 months, and 6 months from a maternal and birth cohort conducted between January 2018 and June 2019. A panel of 6 common ARGs (aac(6′)-Ib, qnrS, blaTEM, ermB, mecA, tetM) were tested, the absolute abundance and positive detection rate by qPCR were calculated. Nonparametric and linear mixed model (LMM) analysis were used to assess the influence of IAP on the absolute abundance of antibiotic resistance genes and the longitudinal changes in their abundance at the three time points. 【Results】 A total of 157 samples from 65 singleton infants were analyzed, including 15 mothers (23.1%) who received IAP. The detection rate of ARGs was high in infants up to six months of age, and the abundance of ARGs tended to increase over time. IAP significantly increased the abundance of the mecA gene in the gut microbiota of vaginally delivered infants at 6 months of age (6.1±1.1 in the VDIAP group vs. 3.8±4.6 in the VDno-IAP group, P=0.046). Additionally, in cesarean section infants, there was a significant increase in the abundance of aac(6′)-Ib genes at 2 months (β=3.81, ,P<0.05), P<0.05] and 6 months of age (β=4.89, ,P<0.001), P<0.001) compared to 3 days of age. 【Conclusions】 The findings suggest that IAP can increase the abundance of ARGs in 6-month-old infants, and this effect is still significant after stratifying by delivery mode. Therefore, the rational and standardized use of intrapartum antibiotics may help reduce the development of antibiotic resistance.

Bone Transplantation/adverse effects* ; Transplantation, Autologous/adverse effects*

Surgical treatment has been established as the standard method for the treatment of intertrochanteric fractures in the elderly. The design of internal fixation devices has become the key to improve surgical outcomes and reduce postoperative complications. Centered on optimizing biomechanical performance and minimally invasive implantation, coupled with continuous material improvements, the design philosophy of internal fixation devices has also been constantly evolving. There have been several milestone advancements, such as the transition from eccentric fixation to central fixation, the adoption of sliding compression fixation, the replacement of traditional screws with spiral blades, and the shift from single to double (combination) nails. However, the incidence of internal fixation-related complications has remained at a relatively high level of 5% to 10%, without significant breakthroughs. Increasing evidence suggests that in-depth analysis of the anatomy, physiological mechanisms, and mechanical transmission characteristics of the proximal femur can help elucidate the root causes of internal fixation failures. Based on this, the proximal femoral bionic nail (PFBN) has emerged as a new design concept. By fully mimicking the anatomical, mechanical, and biological characteristics of the proximal femur, the PFBN can regulate the local mechanical environment, providing a revolutionary solution and a new approach for the treatment of proximal femoral fractures. This innovative design also has the potential to drive the paradigm shift in the treatment strategies of other fractures.

Surgical treatment has been established as the standard method for the treatment of intertrochanteric fractures in the elderly. The design of internal fixation devices has become the key to improve surgical outcomes and reduce postoperative complications. Centered on optimizing biomechanical performance and minimally invasive implantation, coupled with continuous material improvements, the design philosophy of internal fixation devices has also been constantly evolving. There have been several milestone advancements, such as the transition from eccentric fixation to central fixation, the adoption of sliding compression fixation, the replacement of traditional screws with spiral blades, and the shift from single to double (combination) nails. However, the incidence of internal fixation-related complications has remained at a relatively high level of 5% to 10%, without significant breakthroughs. Increasing evidence suggests that in-depth analysis of the anatomy, physiological mechanisms, and mechanical transmission characteristics of the proximal femur can help elucidate the root causes of internal fixation failures. Based on this, the proximal femoral bionic nail (PFBN) has emerged as a new design concept. By fully mimicking the anatomical, mechanical, and biological characteristics of the proximal femur, the PFBN can regulate the local mechanical environment, providing a revolutionary solution and a new approach for the treatment of proximal femoral fractures. This innovative design also has the potential to drive the paradigm shift in the treatment strategies of other fractures.

Objective:To explore whether tryptophan metabolism is related to bone growth by comparing the differences in tryptophan metabolism after rotator cuff tear (RCT) repair between rats with normal bone remodeling capability and those with defective bone remodeling capability.Methods:Of the 50 adult female Sprague Dawley (SD) rats used for this study, 18 were randomly selected to undergo bilateral ovariectomy (OVX) (OVX group), and the remaining 32 underwent bilateral OVX sham surgery (sham surgery group). All rats were maintained in standard conditions. Three months after surgery, 4 rats were randomly selected from OVX group and the sham surgery group, respectively, for Micro CT identification of bone loss at the rat humeral head. The remaining rats in OVX group underwent RCT modeling and surgical repair of acute supraspinatus muscle transection (OVX+RCT group) ( n=14); the remaining rats in the sham surgery group were subjected to either surgical repair of acute supraspinatus muscle transection (RCT group, n=14) or RCT sham surgery (SO group, n=14). The grip power of the rats was tested 2 weeks after surgery. The supraspinatus tendon-bone complex was harvested for evaluation of new bone formation and growth through real-time fluorescence quantitative polymerase chain reaction (qPCR), hematoxylin eosin (HE) staining, and immunohistochemistry (IHC) staining. The tryptophan metabolism was analyzed using ultra high performance liquid chromatography (UPLC). Results:The grip power test showed that SO group had the greatest grip power, followed by RCT group and OVX+RCT group, with statistically significant differences between the 3 groups ( P<0.05). The qPCR showed that the relative expression of osteosclerosis in the tendon-bone complex in SO group was significantly higher than that in OVX+RCT group and RCT group; IHC staining showed that the relative expression of osteocalcin in RCT group was significantly higher than that in SO group and OVX+RCT group ( P<0.05). The UPLC showed that the content of tryptophan in the rotator cuff tendon-bone complex was similar among SO, RCT, and OVX+RCT groups, showing no significant difference ( P>0.05). The qPCR showed that the expression of indoleamine 2, 3-dioxygenase 2 in the Kynurenic acid metabolism pathway showed an increasing trend from SO group to RCT group to OVX+RCT group, with OVX+RCT group significantly higher than SO group ( P<0.05). The expression of 3-hydroxybenzoate 3, 4-dioxygenase in OVX+RCT group was significantly higher than that in RCT group and in SO group ( P<0.001). The subtypes A and B of monoamine oxidase in the 5-hydroxytryptamine metabolism pathway increased from SO group to RCT group to OVX+RCT group. The subtypes A and B of monoamine oxidase in the 5-hydroxytryptamine metabolism pathway increased among SO, RCT, and OVX+RCT groups( P<0.001). The expression of dopamine decarboxylase in the indole metabolism pathway in OVX+RCT group was significantly higher than that in SO group ( P<0.01). The expression of cytochrome P450 oxidoreductase increased from SO group to RCT group to OVX+RCT group ( P<0.001). Conclusions:The tryptophan metabolism in the supraspinatus tendon-bone complex after RCT in rats is mainly dominated by kynurenic acid metabolism, followed by 5-hydroxytryptamine metabolism. In RCT bone remodeling, the 5-hydroxytryptamine metabolic pathway changes the most, followed by the indole pathway. The contents of niacin and xanthurenic acid in the kynurenic acid metabolism pathway are related to bone growth; the 5-hydroxytryptamine, hydroxyindoleacetic acid, and melatonin in the 5-hydroxytryptophan metabolic pathway are related to bone growth; the tryptophan and indole lactate in the indole metabolism pathway are related to bone growth. Therefore, tryptophan metabolism is related to bone growth, providing potential therapeutic targets for RCT repair.

Objective:To understand the current status of the use of aspirin in perioperative period of thoracic surgery in China and the awareness of thoracic surgeons on the prevention and treatment of arterial thromboembolic diseases during the perioperative period.Methods:A survey was conducted among thoracic surgeons nationwide using an electronic questionnaire through a software platform from January 20, 2024 to February 29, 2024. The questionnaire mainly included three parts: basic information, aspirin use, and awareness of arterial thromboembolic diseases, with a total of 27 questions.Results:A total of 1318 valid questionnaires were collected, covering all 33 provincial administrative regions except Taiwan. 69.7%(919/1 318) of thoracic surgeons stopped using aspirin for all patients before surgery; differences could be found in the timing of aspirin withdrawal before surgery and resumption after surgery. 65.1%(858/1 318) of surgeons made perioperative medication decisions based on domestic guidelines or consensus, while 20.9%(276/1 318) of surgeons based their decisions on departmental or personal experience. 87.9%(1 159/1 318) of surgeons believed that it is necessary to develop guidelines for the prevention of arterial thromboembolic diseases in the perioperative period of thoracic surgery.Conclusion:The current use strategy of aspirin in the perioperative period of thoracic surgery in China shows a high degree of inconsistency, and there are also significant differences in the awareness of arterial thromboembolic diseases. It is necessary to establish guidelines for the prevention and treatment of arterial thromboembolic diseases in the perioperative period.