Trauma-associated bone infection is one of the most serious infectious diseases after surgery, characterized by high incidence, complex pathogenic microorganisms, therapeutic difficulty and poor prognosis. Therefore, early accurate identification of pathogenic microorganisms and sensitivity of related antibiotics is very important to the success of surgery as well as of local and systemic antibiotic support therapies. As traditional detection methods have such shortcomings as complex items, numerous indicators, slow speed, a low positive rate, and inability to detect rare pathogenic microorganisms, there is an urgent need for better detection methods to identify pathogenic microorganisms of bone infection. In recent years, polymerase chain reaction (PCR) and metagenomic next generation sequencing (mNGS) have been used in clinical diagnosis of a variety of infectious diseases because of their advantages in accuracy, speed, efficiency, and detection range of pathogenic microorganisms over traditional cultures. PCR and mNGS can also be used as effective tools to diagnose trauma-associated bone infection. This review explores the advantages, disadvantages, development trends and guiding significance of these two techniques in the diagnosis of trauma-associated bone infection.

Femoral intertrochanteric fracture is one of the common types of fractures in the elderly. With the general improvement of medical and living standards, the number of elderly people is increasing, and the problem of osteoporosis has also become relatively prominent. Therefore, low violence can usually cause fractures in this area of the elderly, which has a significant negative impact on the quality of life of elderly patients. With the further development of medical technology and internal fixation materials, the emergence of proximal femoral nail antirotation(PFNA) has greatly improved the treatment effect of femoral intertrochanteric fractures in elderly patients. However, with the increasing number of patients treated, internal fixation failures have gradually been reported. In recent years, proximal femoral biomimetic intramedullary nail(PFBN) has been reported to have good clinical efficacy. Therefore, this article mainly elaborates on the theoretical basis, design characteristics, biomechanics, and clinical efficacy research of PFBN, providing more reference for the clinical treatment of femoral intertrochanteric fractures in elderly patients in the future.

Trauma-associated bone infection is one of the most serious infectious diseases after surgery, characterized by high incidence, complex pathogenic microorganisms, therapeutic difficulty and poor prognosis. Therefore, early accurate identification of pathogenic microorganisms and sensitivity of related antibiotics is very important to the success of surgery as well as of local and systemic antibiotic support therapies. As traditional detection methods have such shortcomings as complex items, numerous indicators, slow speed, a low positive rate, and inability to detect rare pathogenic microorganisms, there is an urgent need for better detection methods to identify pathogenic microorganisms of bone infection. In recent years, polymerase chain reaction (PCR) and metagenomic next generation sequencing (mNGS) have been used in clinical diagnosis of a variety of infectious diseases because of their advantages in accuracy, speed, efficiency, and detection range of pathogenic microorganisms over traditional cultures. PCR and mNGS can also be used as effective tools to diagnose trauma-associated bone infection. This review explores the advantages, disadvantages, development trends and guiding significance of these two techniques in the diagnosis of trauma-associated bone infection.

The widespread of tigecycline resistance gene tet(X4) has a serious impact on the clinical efficacy of tigecycline. The development of effective antibiotic adjuvants to combat the looming tigecycline resistance is needed. The synergistic activity between the natural compound β-thujaplicin and tigecycline in vitro was determined by the checkerboard broth microdilution assay and time-dependent killing curve. The mechanism underlining the synergistic effect between β-thujaplicin and tigecycline against tet(X4)-positive Escherichia coli was investigated by determining cell membrane permeability, bacterial intracellular reactive oxygen species (ROS) content, iron content, and tigecycline content. β-thujaplicin exhibited potentiation effect on tigecycline against tet(X4)-positive E. coli in vitro, and presented no significant hemolysis and cytotoxicity within the range of antibacterial concentrations. Mechanistic studies demonstrated that β-thujaplicin significantly increased the permeability of bacterial cell membranes, chelated bacterial intracellular iron, disrupted the iron homeostasis and significantly increased intracellular ROS level. The synergistic effect of β-thujaplicin and tigecycline was identified to be related to interfere with bacterial iron metabolism and facilitate bacterial cell membrane permeability. Our studies provided theoretical and practical data for the application of combined β-thujaplicin with tigecycline in the treatment of tet(X4)-positive E. coli infection.
Humans ; Tigecycline/pharmacology* ; Escherichia coli/metabolism* ; Reactive Oxygen Species/therapeutic use* ; Plasmids ; Anti-Bacterial Agents/metabolism* ; Escherichia coli Infections/microbiology* ; Bacteria/genetics* ; Microbial Sensitivity Tests

OBJECTIVE To compare the short-term therapeutic effect and safety of bevacizumab versus anlotinib respectively combined with chemotherapy drug in the treatment of epidermal growth factor receptor tyrosine kinase inhibitors （EGFR-TKI） acquired resistant advanced lung adenocarcinoma. METHODS The information of 84 patients with EGFR-TKI acquired resistant advanced lung adenocarcinoma in the Third People’s Hospital of Chengdu was analyzed retrospectively during Jun. 2019-Oct. 2021. The patients were divided into chemotherapy group （32 cases）， anlotinib combined chemotherapy group （24 cases） and bevacizumab combined chemotherapy group （28 cases）. Patients in the chemotherapy group were given Pemetrexed disodium for injection and Carboplatin injection， and symptomatic treatment was given for adverse reactions. On the first day of chemotherapy， patients in the anlotinib combined chemotherapy group received Anlotinib hydrochloride capsules 10 mg orally， once a day， for 14 consecutive days and 7 days of discontinuation， based on the treatment of the chemotherapy group. Patients in the bevacizumab combined chemotherapy group were given Bevacizumab injection of 15 mg/kg intravenously 1 day before chemotherapy， based on the treatment of the chemotherapy group. Three groups of patients were treated for a total of four cycles， with one cycle every three weeks. The overall response rate （ORR）， disease control rate （DCR）， median progression-free survival （mPFS）， and the changes of serum tumor markers were compared among three groups before and after treatment； meanwhile， the occurrence of adverse drug reactions was recorded， and the 1-year survival rate was followed up. RESULTS After 4 treatment cycles， ORR and DCR of bevacizumab combined chemotherapy group and anlotinib combined chemotherapy group were higher than chemotherapy group （P＜0.05）； mPFS of the two groups were significantly longer than chemotherapy group， and DCR of anlotinib combined chemotherapy group was significantly higher than bevacizumab combined chemotherapy group （P＜0.05）. After 4 treatment cycles， the serum levels of tumor markers in three groups were significantly lower than before treatment， and both combined chemotherapy groups were significantly lower than chemotherapy group （P＜0.05）. There was no statistically significant difference in the incidence of adverse reactions such as nausea， vomiting， bone marrow suppression， and 1-year survival rate among the three groups of patients （P＞0.05）. CONCLUSIONS Bevacizumab and anlotinib combined with chemotherapy drug are effective and safe in the treatment of advanced lung adenocarcinoma with acquired EGFR-TKI resistance.

Objective:To compare the clinical effects robot navigation assisted and conventional proximal femoral nail antirotation (PFNA) implantation and fixation in the treatment of elderly femoral trochanteric fractures.Methods:A total of 86 elderly patients with tuberosity fracture of the femur were admitted as research samples from January to March in 2022 in the Department of Trauma Orthopaedic, Xi′an Honghui Hospital Affiliated to Xi′an Jiaotong University, including 37 males and 49 females, who aged from 63 to 92 years, with an average age of (79.6 ± 6.9) years. All patients were treated with intramedullary nails (PFNA), 32 with dimensity robotic-assisted therapy (robot group) and 54 with traditional methods (conventional group). The length of incision, the number of intraoperative fluoroscopy, the amount of intraoperative blood loss, and the operation time were recorded. The occurrence of postoperative complications in the two groups was observed. The rate of excellent hip Harris score at 3 month after surgery was compared between the two groups. Measurement data with normal distribution were represented as mean ± standard deviation( ± s), and the comparison between groups was conducted using the t-test; the comparison of count data were represented as [ n(%)], and was conducted by Chi-square test or Fisher exact probability between groups. Results:All patients were followed up for 9 to 12 months, with an average of (10.6 ± 0.9) months. The incision length and tip apex distance (TAD) of the robot group were (3.40±0.82) cm and (21.85±1.44) mm, which were smaller than (4.82±0.75) cm and (26.83±1.75) mm in the conventional group ( P<0.05 for all). The number of intraoperative fluoroscopy and guide needle adjustment [(14.53±3.26) and 0 times] in the robot group were less than those in the conventional group [(20.67±4.84) and (2.83±1.42)] ( P<0.05). The intraoperative blood loss and drainage rate of the robot group were (87.03±9.41) and (46.40±8.91) mL, which were smaller than that of the conventional group [(110.00±12.52) and (69.62±10.22) mL] ( P<0.05). There was no significant difference in the number of days of hospitalization and operation time between the two groups ( P>0.05). The postoperative complication rate in the robot group was 9.4%, which was lower than that in conventional group (42.6%), and the difference was statistically significant ( χ2=11.88, P=0.036). The excellent rate of postoperative hip joint function in the robot group was 75.0%, and the conventional group was 66.7%, and there was no significant difference between the two groups ( χ2=0.66, P=0.416). Conclusion:Robot-assisted navigation downward PFNA surgery can have good clinical effect in the treatment of femoral tuberosity fracture in the elderly, which can reduce the number of surgical incisions and intraoperative fluoroscopy, and reduce the incidence of postoperative complications, which is helpful to achieve minimally invasive surgery and rapid recovery of elderly patients with femoral tuberosity fracture.

Objective:To evaluate the clinic efficacy of channel bone grafting [preservation of the sclerotic bone at the broken nonunion ends and fixation with limited contact dynamic compression plate (LC-DCP)] in the treatment of postoperative atrophic nonunion of middle clavicular fracture.Methods:The 41 patients were retrospectively analyzed who had been treated at Department of Orthopaedics and Traumatology, Xi'an Hong-Hui Hospital for atrophic nonunion after internal fixation of middle clavicular fracture from June 2015 to December 2019. They were 23 males and 18 females, with a mean age of 47.6 years (from 28 to 63 years). The left side was affected in 25 cases and the right side in 16 cases. The time interval between initial fracture surgery and nonunion surgery averaged 18.5 months (from 9 to 40 months). Thirty-six cases had undergone one operation and 5 cases 2 operations before admission. The length of bone defect was measured during operation. All nonunions were treated with construction of a graft channel, iliac bone graft and LC-DCP internal fixation above the clavicle. The upper limb function of the affected side was evaluated by the Disabilities of Arm, Shoulder and Hand (DASH) 12 months after operation.Results:The 41 patients were followed up for an average of 13.6 months (from 12 to 15 months). A bone defect ≤2.0 cm was found in 25 cases and that >2.0 cm in 16 ones. Nonunion healed in all patients after an average time of 14 weeks (from 12 to 16 weeks). One patient reported continuous pain in the donor area after operation and the other developed deep venous thrombosis at the right lower limb. The DASH upper limb scores at 12 months after operation averaged 14.7.Conclusion:Channel bone grafting is a feasible clinical treatment of postoperative atrophic nonunion of middle clavicular fracture, because it preserves the sclerotic bone at the broken nonunion ends, reduces the amount of iliac bone graft and leads to fine clinic efficacy.

Emergence of the colistin resistance gene,mcr-1,has attracted worldwide attention.Despite the prevalence of mcr-1-positive Escherichia coli(MCRPEC)strains in human carriage showing a significant decrease between 2016 and 2019,genetic differences in MCRPEC strains remain largely unknown.We therefore conducted a comparative genomic study on MCRPEC strains from fecal samples of healthy human subjects in 2016 and 2019.We identified three major differences in MCRPEC strains between these two time points.First,the insertion sequenceISApll1 was often deleted and the percentage of mcr-1-carrying IncI2 plasmids was increased in MCRPEC strains in 2019.Second,the antibiotic resistance genes(ARGs),aac(3)-Ⅳa and blaCTX-M-1,emerged and coexisted with mcr-1 in 2019.Third,MCRPEC strains in 2019 contained more viru-lence genes,resulting in an increased proportion of extraintestinal pathogenic E.coli(ExPEC)strains(36.1％)in MCRPEC strains in 2019 compared to that in 2016(10.5％),implying that these strains could occupy intestinal ecological niches by competing with other commensal bacteria.Our results suggest that despite the significant reduction in the prevalence of MCRPEC strains in humans from 2016 to 2019,MCRPEC exhibits increased resistance to other clinically important ARGs and contains more virulence genes,which may pose a potential public health threat.

Objective:To characterize the biomechanical performance of our self-designed novel blocking screws in the treatment of distal tibial fractures.Methods:Thirty artificial composite tibial bones were used to create models of unstable distal tibial fracture (AO type 43-A3) which were randomized into 3 even groups ( n=10) according to modes of fixation. Group A was subjected to fixation with intramedullary nails only with merely preset holes reserved for the blocking screws, group B to fixation with intramedullary nails plus conventional anteroposterior blocking screws, and group C to fixation with intramedullary nails plus novel lateral blocking screws. In all the 3 groups, a lateral bending stress test was conducted to record the maximum transversal displacement of the intramedullary nail, a fatigue test to observe the structural abnormality in the model and an axial stress test to record the maximum axial displacement of the intramedullary nail-bone structure. The 3 groups were compared in structural abnormality, the maximum transversal displacement of the intramedullary nail and the maximum axial displacement of the intramedullary nail-bone structure. Results:The lateral bending stress tests showed the maximum transversal displacements were (5.02±1.03) mm; (4.19±0.64) mm and (4.18±0.65) mm in groups A, B and C; compared with group A, the maximum transversal displacement decreased by 16.6%( P=0.027) in group B and decreased by 16.8%( P=0.025) in group C, showing significant differences but there was no significant difference in the maximum transversal displacement between groups B and C ( P=0.978). In the fatigue test, all models showed no structural abnormality under cyclic loading. In the axial stress test, the maximum axial displacements of the intramedullary nail-bone structure were, respectively, (5.69±0.75) mm, (5.31±0.61) mm and (5.51±0.65) mm in groups A, B and C, showing no statistically significant difference among the 3 groups ( P>0.05). Conclusion:Our self-designed novel blocking screws can be a new means in clinical application, because they are similar to conventional blocking screws in increasing the stability of nail-bone construct and other biomechanical performance.

Objective:To study the influence of anticoagulation timing on incidence of perioperative deep venous thrombosis (DVT) in elderly patients with hip fracture.Methods:A retrospective analysis was made of the 179 elderly patients with hip fracture who had been admitted to Department of Orthopedics and Traumaology, Hong-Hui Hospital from July 2017 to December 2018. They were 78 males and 101 females, aged from 62 to 91 years (mean, 79.5 years). There were 79 femoral neck fractures and 100 intertrochanteric fractures, 109 of which were treated by internal fixation and 70 by hip replacement. The patients were divided into 3 groups depending on the timing of anticoagulation after injury. In group 1 of 74 cases, anticoagulation started <24 h after injury; in group 2 of 36 cases, anticoagulation started 24 to 48 h after injury; in group 3 of 69 cases, anticoagulation started >48 h after injury. Anticoagulation continued until 12 h before surgery in all patients but was resumed 8 to 12 h after surgery. The 3 groups were compared in incidence of perioperative DVT.Results:The 3 groups were comparable due to insignificant differences between them in their pre-operative general data ( P>0.05). DVT occurred perioperatively in 84 patients, yielding an incidence of 46.9% (84/179). The incidences of perioperative DVT were 27.0% (20/74), 47.2% (17/36) and 68.1% (47/69) in groups 1, 2 and 3, respectively, showing significant differences ( χ2=24.206, P<0.001), between any 2 groups ( P<0.05). Conclusion:Since the earlier anticoagulation starts after injury the lower incidence of perioperative DVT in elderly patients with hip fracture, early standardized prophylactic anticoagulation after injury can effectively reduce incidence of perioperative DVT.