Objectives: . This study aimed to explore the role of the Pcdh15 gene in hearing maintenance and to examine the effects of its deficiency on cochlear structure, cochlear function, and hearing loss in mice. Methods: . CRISPR/Cas9 technology was used to generate Pcdh15 knockout (KO) mice. Auditory function was evaluated using hearing tests, while histological approaches were employed to assess morphological changes in cochlear hair cells and spiral ganglion neurons (SGNs). RNA sequencing (RNA-seq) was performed on cochlear tissue from postnatal day 18 (P18) wild-type (WT) and Pcdh15 KO mice to identify differentially expressed genes (DEGs). These DEGs were subjected to functional annotation and pathway analysis, with particular emphasis on oxidative phosphorylation (OXPHOS). Reactive oxygen species (ROS) levels were quantified using flow cytometry and DCFH-DA assays. Results: . Pcdh15 KO mice exhibited progressive sensorineural hearing loss, which worsened to profound deafness by P18. Notably, cochlear hair cells and SGNs showed substantial loss and pronounced morphological abnormalities, particularly within the basal high-frequency region. RNA-seq analysis identified 1,359 DEGs, including 1,024 downregulated and 335 upregulated genes. Pathway analysis indicated that Pcdh15 deficiency was associated with inhibition of the OXPHOS pathway, potentially disrupting mitochondrial respiratory chain complexes I, III, IV, and V and thereby impairing energy production and ATP metabolism. In addition, early-stage cochleae from KO mice demonstrated elevated ROS levels and increased oxidative stress, suggesting that redox imbalance may contribute to hearing damage. Conclusion . Pcdh15 plays a critical role in hearing maintenance. Its deficiency is associated with severe hearing loss and marked cochlear abnormalities, which are linked to inhibition of OXPHOS, disruption of energy metabolism, and exacerbation of oxidative stress. Together, these findings provide new insights into the mechanisms underlying hearing loss and suggest potential targets for therapeutic intervention.

OBJECTIVE: To compare the short-term clinical efficacy and safety of closed reduction with Kirschner wire fixation versus open reduction with plate fixation for treating osteoporotic Colles' fractures in middle-aged and elderly patients. METHODS: Between January 2018 and January 2023, 119 patients with Colles fractures were retrospectively analyzed, including 39 males and 80 females, aged from 48 to 74 years old with an average of(60.58±6.71) years old. The time from injury to operation ranged 1 to 13 days with an average of (5.29±2.52) days. According to the surgical method, they were divided into Kirschner wire fixation group (Kirschner wire group) and plate internal fixation group (plate group). In Kirschner wire group, there were a total of 68 patients, comprising 21 males and 47 females. The average age was (61.15±6.24) years old, ranged from 49 to 74 years old. Among them, 41 cases involved the left side while 27 cases involved the right side. In the plate group, there were a total of 51 patients, including 18 males and 33 females. The average age was (59.78±5.71) years old ranged from 48 to 72 years old. Among them, there were 31 cases on the left side and 20 cases on the right side. The following parameters were recorded before and after the operation:operation time, intraoperative blood loss, hospitalization days, hospitalization expenses, postoperative complications, and radiographic parameters of distal radius (distal radius height, ulnar deviation angle, palmar tilt angle). The clinical efficacy was evaluated at 3 and 12 months after the operation using Gartland-Werley and disabilites of the arm shoulder and hand (DASH) scores. RESULTS: The patients in both groups were followed up for a duration from 12 to 19 months with an average of(13.32±2.02) months. The Kirschner wire group exhibited significantly shorter operation time compared to the plate group 27.91(13.00, 42.00) min vs 67.52(29.72, 105.32) min, Z=-8.74, P=0.00. Intraoperative blood loss was also significantly lower in the Kirschner wire group than in the plate group 3.24(1.08, 5.40) ml vs 21.91(17.38, 26.44) ml, Z=-9.31, P=0.00. Furthermore, patients in the Kirschner wire group had a shorter length of hospital stay compared to those in the plate group (8.38±2.63) days vs (11.40±2.78) days, t=-3.12, P=0.00. Additionally, hospitalization cost was significantly lower in the Kirschner wire group than in the plate group 10 111.29(6 738.98, 13 483.60) yuan vs 15 871.11(11 690.40, 20 051.82) yuan, Z=-5.62, P=0.00. The incidence of complications was 2 cases in the Kirschner wire group and 1 case in the plate group, with no statistically significant difference(P>0.05). At 3 months postoprative, the radial height of the Kirschner wire group was found to be significantly smaller than that of the plate group, with measurements of (11.45±1.69) mm and (12.11±1.78) mm respectively (t=-2.06, P=0.04). However, there were no statistically significant differences observed in ulnar deviation angle and palmar tilt angle between the two groups (P>0.05). The DASH score and Gartland-Werley score in the Kirschner group were significantly higher than those in the plate group at 3 months post-operation (19.10±9.89) vs (13.47±3.51), t=4.34, P=0.00;(11.15±3.61) vs (6.41±2.75), t=8.13, P=0.00). However, there was no significant difference between the two groups at 12 months post-operation (P>0.05). CONCLUSION Compared to plate internal fixation, closed reduction with Kirschner wire support fixation yields a slightly inferior recovery of radial height;however, there is no significant disparity in the functional score of the affected limb at 12 months post-operation. Nonetheless, this technique offers advantages such as shorter operation time, reduced intraoperative blood loss, decreased hospitalization duration, and lower cost.
Humans ; Female ; Male ; Middle Aged ; Aged ; Fracture Fixation, Internal/instrumentation* ; Bone Wires ; Bone Plates ; Retrospective Studies ; Colles' Fracture/surgery* ; Minimally Invasive Surgical Procedures/methods* ; Open Fracture Reduction/methods* ; Osteoporotic Fractures/surgery*

OBJECTIVE: To establish a two-segment vertebrectomy model using the finite element method, and to measure and compare the biomechanical properties of the lower cervical anterior transpedicular root screw (ATPRS) plate system, lower cervical anterior pedicle screw (ATPS) plate system, and lower cervical anterior cervical locked-plate (ACLP) system on this model. METHODS: CT data of the cervical spine (C₀-T₁) from a 34-year-old healthy adult male volunteer were collected. A nonlinear complete model of the lower cervical spine (C₃-C₇) was established using Mimics 10.01 software, based on which the ATPRS fixation model, ATPS fixation model, and ACLP fixation model were constructed respectively. An axial pressure of 75 N and a pure couple moment of 1.5 N·m were applied to C3 to make the model perform flexion-extension, left-right lateral bending, and left-right rotation movements. The range of motion (ROM) and stress distribution of each model under different working conditions were compared. RESULTS: The ROM of the C₄-C₇ segments in the ACLP group, ATPS group, and ATPRS group was reduced to 0.65° (-95.2%), 0.58° (-95.7%), and 0.62° (-95.4%) respectively compared with the intact model during flexion-extension movement;during lateral bending movement, it was reduced to 0.58° (-95.2%), 0.51°(-95.8%), and 0.60° (-95.1%) respectively;during rotation movement, it was reduced to 1.17° (-89.6%), 1.26° (-88.8%), and 1.27°(-88.7%) respectively. In terms of the stress on the titanium mesh graft, the ATPS group and ATPRS group had the maximum load during extension and the minimum load during flexion. Compared with the ACLP group, the stress on the titanium mesh graft in ATPS and ATPRS decreased by (-33.7%) and (-15.8%) in flexion, (-29.4%) and (-13.2%) in extension, (-26.2%) and (-23.4%) in lateral bending, and (-18.8%) and (-5.4%) in rotation, respectively. In terms of bone-screw interface stress, the peak bone stress near the C₇ screw in the ACLP group, ATPS group, and ATPRS group increased by 49.2%, 45.0%, and 47.6% respectively compared with the peak bone stress near the C₄ screw during extension. However, during flexion and lateral bending, there was no significant difference in the peak bone stress near the C₄ and C₇ screws. During rotation, the difference between the peak bone stress near the C₄ screw and that near the C₇ screw showed that in the ACLP group, left rotation (37.6%) was similar to right rotation (36.7%), while in the ATPS group and ATPRS group, left rotation was lower than right rotation. CONCLUSION Compared with the ACLP group, the ATPS group and ATPRS group have greater fixation stiffness and more stable fixation. However, in rotational movement, due to the uneven distribution of fixation stiffness, the stress distribution during torsion is uneven, but it is still better than the ACLP group. This indicates that ATPRS, like ATPS, has good primary stability, providing favorable conditions for bone graft fusion.
Humans ; Finite Element Analysis ; Male ; Cervical Vertebrae/physiopathology* ; Adult ; Biomechanical Phenomena ; Bone Plates ; Bone Screws ; Range of Motion, Articular ; Fracture Fixation, Internal

OBJECTIVE: To compare the biomechanical properties of four internal fixation methods in a lower cervical spine injury model using the finite element method. METHODS: Cervical CT data of a 28-year-old healthy adult male were utilized to establish a finite element model of the normal cervical spine and a lower cervical spine three-column injury model. Four internal fixation methods were then applied to the three-column injury model, resulting in four groups:Group A, anterior cervical locked-plate(ACLP) fixation system model(anterior approach);Group B, posterior cervical pedicle screw fixation model (posterior approach);Group C, combined anterior and posterior cervical pedicle screw fixation model; Group D, Novel composite anterior cervical internal fixation model. A 75 N axial compressive load and a 1.0 N·m pure moment were applied to the upper surface of the cervical spine model to simulate flexion, extension, rotation, and lateral bending movements. The intervertebral range of motion(ROM) and stress distribution of the internal fixators under different motion conditions were compared across all models. RESULTS: Compared with the normal model, the reductions in overall intervertebral ROM for each group under flexion, extension, rotation, and lateral bending were as follows:Group A, 24.04°, 23.12°, 6.24°, and 9.06°;Group B, 24.42°, 24.34°, 6.48°, and 9.20°;Group C, 25.43°, 25.29°, 7.17°, and 9.57°;Group D, 24.75°, 25.5°, 6.71°, and 9.12°. The peak stress values of the internal fixators in each group were:Group A, 53.9 MPa, 79.9 MPa, 61.4 MPa, and 80.3 MPa;Group B, 218.3 MPa, 105.4 MPa, 206.6 MPa, and 186.8 MPa;Group C, 40.8 MPa, 97.2 MPa, 47.1 MPa, and 39.4 MPa;Group D, 93.0 MPa, 144.0 MPa, 64.8 MPa, and 106.3 MPa. CONCLUSION The biomechanical properties of the novel composite anterior cervical internal fixation method are similar to those of the combined anterior-posterior fixation method, and superior to both the anterior cervical ACLP plate-screw fixation and posterior cervical pedicle screw fixation methods.
Humans ; Finite Element Analysis ; Cervical Vertebrae/physiopathology* ; Male ; Biomechanical Phenomena ; Adult ; Fracture Fixation, Internal/methods* ; Range of Motion, Articular

PURPOSE: We carried out the study aiming to explore and analyze the risk factors, the distribution of pathogenic bacteria, and their antibiotic-resistance characteristics influencing the occurrence of surgical site infection (SSI), to provide valuable assistance for reducing the incidence of SSI after traumatic fracture surgery. METHODS: A retrospective case-control study enrolling 3978 participants from January 2015 to December 2019 receiving surgical treatment for traumatic fractures was conducted at Tangdu Hospital of Air Force Medical University. Baseline data, demographic characteristics, lifestyles, variables related to surgical treatment, and pathogen culture were harvested and analyzed. Univariate analyses and multivariate logistic regression analyses were used to reveal the independent risk factors of SSI. A bacterial distribution histogram and drug-sensitive heat map were drawn to describe the pathogenic characteristics. RESULTS: Included 3978 patients 138 of them developed SSI with an incidence rate of 3.47% postoperatively. By logistic regression analysis, we found that variables such as gender (males) (odds ratio (OR) = 2.012, 95% confidence interval (CI): 1.235 - 3.278, p = 0.005), diabetes mellitus (OR = 5.848, 95% CI: 3.513 - 9.736, p < 0.001), hypoproteinemia (OR = 3.400, 95% CI: 1.280 - 9.031, p = 0.014), underlying disease (OR = 5.398, 95% CI: 2.343 - 12.438, p < 0.001), hormonotherapy (OR = 11.718, 95% CI: 6.269 - 21.903, p < 0.001), open fracture (OR = 29.377, 95% CI: 9.944 - 86.784, p < 0.001), and intraoperative transfusion (OR = 2.664, 95% CI: 1.572 - 4.515, p < 0.001) were independent risk factors for SSI, while, aged over 59 years (OR = 0.132, 95% CI: 0.059 - 0.296, p < 0.001), prophylactic antibiotics use (OR = 0.082, 95% CI: 0.042 - 0.164, p < 0.001) and vacuum sealing drainage use (OR = 0.036, 95% CI: 0.010 - 0.129, p < 0.001) were protective factors. Pathogens results showed that 301 strains of 38 species of bacteria were harvested, among which 178 (59.1%) strains were Gram-positive bacteria, and 123 (40.9%) strains were Gram-negative bacteria. Staphylococcus aureus (108, 60.7%) and Enterobacter cloacae (38, 30.9%) accounted for the largest proportion. The susceptibility of Gram-positive bacteria to Vancomycin and Linezolid was almost 100%. The susceptibility of Gram-negative bacteria to Imipenem, Amikacin, and Meropenem exceeded 73%. CONCLUSION Orthopedic surgeons need to develop appropriate surgical plans based on the risk factors and protective factors associated with postoperative SSI to reduce its occurrence. Meanwhile, it is recommended to strengthen blood glucose control in the early stage of admission and for surgeons to be cautious and scientific when choosing antibiotic therapy in clinical practice.
Humans ; Surgical Wound Infection/epidemiology* ; Male ; Female ; Risk Factors ; Retrospective Studies ; Middle Aged ; Adult ; Case-Control Studies ; Fractures, Bone/surgery* ; Aged ; Drug Resistance, Bacterial ; Logistic Models ; Anti-Bacterial Agents/therapeutic use* ; Incidence ; Bacteria/drug effects*

Mycophenolic acid (MPA), the active moiety of both mycophenolate mofetil (MMF) and enteric-coated mycophenolate sodium (EC-MPS), serves as a primary immunosuppressant for maintaining solid organ transplants. Therapeutic drug monitoring (TDM) enhances treatment outcomes through tailored approaches. This study aimed to develop an evidence-based guideline for MPA TDM, facilitating its rational application in clinical settings. The guideline plan was drawn from the Institute of Medicine and World Health Organization (WHO) guidelines. Using the Delphi method, clinical questions and outcome indicators were generated. Systematic reviews, Grading of Recommendations Assessment, Development, and Evaluation (GRADE) evidence quality evaluations, expert opinions, and patient values guided evidence-based suggestions for the guideline. External reviews further refined the recommendations. The guideline for the TDM of MPA (IPGRP-2020CN099) consists of four sections and 16 recommendations encompassing target populations, monitoring strategies, dosage regimens, and influencing factors. High-risk populations, timing of TDM, area under the curve (AUC) versus trough concentration (C₀), target concentration ranges, monitoring frequency, and analytical methods are addressed. Formulation-specific recommendations, initial dosage regimens, populations with unique considerations, pharmacokinetic-informed dosing, body weight factors, pharmacogenetics, and drug‍-‍drug interactions are covered. The evidence-based guideline offers a comprehensive recommendation for solid organ transplant recipients undergoing MPA therapy, promoting standardization of MPA TDM, and enhancing treatment efficacy and safety.
Mycophenolic Acid/administration & dosage* ; Drug Monitoring/methods* ; Humans ; Organ Transplantation ; Immunosuppressive Agents/administration & dosage* ; Delphi Technique

Objective:To investigate the clinicopathological features including immunophenotype, molecular characteristics, differential diagnosis and prognosis of SMARCB1-deficient renal medullary carcinoma (RMC) without sickle cell trait.Methods:The clinicopathological data of 12 cases of SMARCB1-deficient RMC without sickle cell trait were collected from 7 domestic institutions during the period of 2015 to 2024. Their clinical characteristics, morphological features and immunohistochemical properties were observed and analyzed. High-throughput DNA-targeted next-generation sequencing was performed, and follow-up data were gathered along with relevant literature review.Results:Among the 12 patients, 5 were female and 7 were male. The patients age ranged from 27 to 84 years with a median age of 58.5 (46.0, 71.0) years. None of them had sickle cell disease or other hemoglobinopathies. Eight cases occurred in the left kidney and 4 cases were located in the right kidney. The average maximum diameter of the tumor was 6.1 (4.0,7.5) cm, with a range of 2.0 to 14.9 cm (the median maximum diameter 5.5 cm). Histologically, the tumors showed poorly differentiated adenocarcinoma, arranged in solid and tubular patterns. Papillary structure was noted in 5 cases, cribriform structure in 3 cases, rhabdoid differentiation in 3 cases, and sarcomatoid differentiation in 2 cases. Inflammatory desmoplastic stromal reaction was observed in 8 cases, among which stromal myxoid degeneration was seen in 6 cases. Tumor necrosis was apparent in 6 cases. The tumor cells had abundant eosinophilic or clear cytoplasm and prominent nucleoli. The nuclear grading was grade 3 or 4 according to the International Society of Urological Pathology (ISUP). Immunohistochemical staining showed that the tumor cells of all 12 cases expressed PAX8 and loss of SMARCB1/INI1 protein expression, and 5 of 10 cases expressed OCT3/4. Seven samples had valid archived paraffin tissues for high-throughput DNA-targeted next-generation sequencing. The results showed that all 7 cases had pathogenic mutations in the SMARCB1 gene. The mutation sites included exon5 c.595A>T (p.K199*), exon2 c.200_207del (p.S67*), exon2 p.G69VfsTer16, exon7 c.986G>T (p.S329I), exon7 c.886A>T (p.K296*), exon6 c.635T>A (p.L212*), exon5 c.577del (p.M193Wfs16), and exon6 c.784del (p.V262Sfs5). Follow-up data were obtained for 6 of 12 patients. Among them, 1 patient had lung and bone metastases, 1 patient had liver and bone metastases and 1 patient had multiple bone metastases at the time of diagnosis; 1 patient had bone metastases 5 months after surgery. One patient died of postoperative complications 10 days after surgery, 4 patients died of tumors (the survival time ranged from 4 to 8 months), and 1 patient had no recurrence or metastasis during the 8-month follow-up after surgery.Conclusions:SMARCB1-deficient RMC without sickle cell trait is a highly aggressive and poorly differentiated renal cell carcinoma. It has similar histomorphology, immunophenotype, molecular characteristics and prognosis to RMC, which further supports that it is a sporadic subtype of RMC related to sickle cell trait.

Severe open tibiofibular fractures account for approximately 28.1% of all open fractures. Among them, Gustilo-Anderson type IIIB/C fractures present significant clinical challenges due to associated bone and soft tissue defects, high infection rates, and risk of amputation. Inadequate preoperative assessment may lead to suboptimal emergency surgical planning or intraoperative complications. Historically, external fixation was often preferred, but this approach has been associated with limitations such as restricted joint mobility, delayed bone union, joint stiffness, and disuse osteoporosis, resulting in poor functional recovery. With advancements of debridement techniques, standardization of antibiotic use, and popularization of early soft tissue coverage, early internal fixation has gained broader acceptance. Nevertheless, controversies persist regarding the choice of fixation method, timing of definitive fixation, use of reamed versus unreamed intramedullary nailing, and necessity of fibular fixation. To standardize the diagnosis and early management of severe open tibiofibular fractures, reduce complication rates, and improve functional recovery, the Society of Microsurgery of the Chinese Medical Association organized a panel of domestic experts to develop the Evidence-based guideline for the diagnosis and early fixation of severe open tibiofibular fractures ( version 2025), using evidence-based methodology. The guidelines provided 12 recommendations covering diagnostic and early fixation strategies of severe open tibiofibular fractures, aiming to provide clinicians with scientifically grounded and standardized guidance.

For middle-aged and elderly patients with conditions such as spinal fractures and degenerative spinal diseases, spinal internal fixation is a core surgical procedure for reconstructing spinal stability, heavily relying on the biomechanical stability provided by pedicle screw systems. Whereas, these patients are often complicated by osteoporosis that can significantly compromise the stability of the bone-pedicle screw interface, leading to a marked increase in pedicle screw loosening and surgical failure rates. The bone cement-augmented pedicle screw technique, which involves injecting bone cement into the vertebral body or screw trajectory to optimize the mechanical properties of the bone-pedicle screw composite, has been proven to significantly enhance fixation strength and effectively prevent screw-related failures, thereby reducing the incidence of internal fixation failure in high-risk populations undergoing spinal fusion. However, the widespread clinical application of this technique has faced challenges such as inaccurate clinical decision-making (indication and contraindication selection), non-standardized operative practices, and insufficient awareness of complication prevention, resulting in considerable variability in clinical outcomes and even severe complications. To address this, Prof. Luo Fei from First Affiliated Hospital of Army Medical University initiated the project and the Chinese Association Orthopaedic Surgeons organized relevant experts to develop the Evidence-based clinical practice guideline for bone cement-augmented pedicle screw technique ( version 2025), based on current evidence. The guidelines put forward 8 recommendations regarding the clinical value, scope of application, and operational standards of the technique, aiming to provide evidence-based medical support and technical standardization for clinical decision-making.

Instrument separation is a critical complication during root canal therapy, impacting treatment success and long-term tooth preservation. The etiology of instrument separation is multifactorial, involving the intricate anatomy of the root canal system, instrument-related factors, and instrumentation techniques. Instrument separation can hinder thorough cleaning, shaping, and obturation of the root canal, posing challenges to successful treatment outcomes. Although retrieval of separated instrument is often feasible, it carries risks including perforation, excessive removal of tooth structure and root fractures. Effective management of separated instruments requires a comprehensive understanding of the contributing factors, meticulous preoperative assessment, and precise evaluation of the retrieval difficulty. The application of appropriate retrieval techniques is essential to minimize complications and optimize clinical outcomes. The current manuscript provides a framework for understanding the causes, risk factors, and clinical management principles of instrument separation. By integrating effective strategies, endodontists can enhance decision-making, improve endodontic treatment success and ensure the preservation of natural dentition.
Humans ; Root Canal Therapy/adverse effects* ; Consensus ; Root Canal Preparation/adverse effects*