ObjectiveTo summarize the related research results of open wedge high tibial osteotomy (OWHTO) complicated with lateral hinge fracture. MethodsTo review the relevant literature of OWHTO at home and abroad in recent years and summarize and analyse the clinical experience. ResultsThe lateral hinge rupture may occur during the OWHTO, which may lead to the loss of correction angle after operation, delayed healing or non-union of osteotomy and so on. The lateral hinge plays an important role in the stability of the osteotomy. During the operation, the " safe zone” internal osteotomy can be used to protect the bone. Once the lateral hinge breaks, the TomoFix plate can be used to obtain the sufficient stability. For patients with lateral hinge rupture, functional exercise and full weight loading time should be guided by hinge breakage classification. ConclusionThe intact lateral hinge is beneficial to the healing and rehabilitation of OWHTO. The lateral hinge should be paid enough attention by clinicians.
Objective To explore a new method for the pre-degeneration of peripheral nerve in vitro for obtaining many effective Schwann cells so as to provide a large number of seed cells for the research and application of tissue engineered nerves. Methods The bone marrow derived cells (BMDCs) from transgenic green fluorescent protein C57BL/6 mouse and the sciatic nerve segments from the C57BL/6 mouse were co-cultured to prepare the pre-degeneration of sciatic nerve in vitro (experimental group, group A), and only sciatic nerve was cultured (control group, group B). At 7 days after culture, whether BMDCs can permeate into the sciatic nerve in vitro for pre-degeneration was observed by gross and immunohistofluorescence staining. And then Schwann cells were obtained from the sciatic nerves by enzymic digestion and cultured. The cell number was counted, and then the purity of primary Schwann cells was determined using immunohistofluorescence staining and flow cytometer analysis. Results At 7 days after pre-degeneration, gross observation showed that enlargement was observed at nerve stumps, and neuroma-like structure formed; the group A was more obvious than group B. Immunohistofluorescence staining showed many BMDCs permeated into the nerve segments, with positive F4/80 staining in group A. After culture, the yield of Schwann cells was (5.59 ± 0.19) × 104 /mg in group A and (3.20 ± 0.21) × 104/mg in group B, showing significant difference (t=2.14, P=0.03). At 48 hours after inoculation, the cells had blue bipolar or tripolar cell nuclei with small size and red soma by immunohistofluorescence staining; fibroblasts were flat polygonal with clear nucleus and nucleolus, showing negative p75NTR staining; and there were few of fibroblasts in group A. The purity of Schwann cells was 88.4% ± 5.8% in group A and 76.1% ± 3.7% in group B, showing significant difference (t=2.38, P=0.04). And the flow cytometer analysis showed that the purity was 89.6% in group A and 74.9% in group B. Conclusion BMDCs can promote the pre-degeneration of peripheral nerve in vitro, and it is a new method to effectively obtain Schwann cells for tissue engineered nerve.
Objectives Based on the Global Minimum Essential Requirement in Medical Education (GMER), we tried to use the theories and methods of “competency” as a reference to introduce the concept of “competency” into medical education in China and to investigate the skills that medical graduates need for their prospective clinical work. Methods According to a literature search and expert interviews, the Glossary of Medical Graduates’ Competencies was built to define the competencies needed by medical graduates. Students’ attitudes toward those competencies were surveyed by questionnaires. Factor analysis and Analytic Hierarchy Process (AHP) were used to analyze the data and to build the Medical Graduates’ Competency Model. Results The competencies of medical graduates could be divided into six groups. The weighting of each competency group and specific competence was different. Conclusion The Medical Graduate Competency Model can be used to evaluate medical graduates’ capacities. It has significant reference value for medical education, in terms of the evaluation of medical graduates and the reform of teaching methods.
The meta-analysis of rare binary data is a difficulty in the field of medical research, and its methodology remains immature. The traditional meta-analysis technique is based on the normal-normal model of fixed effects analysis or random-effects analysis, however there are methodological problems in this method. Stijnen proposed an exact within-study likelihood models (EWLM) meta-analysis technique based on the generalized linear mixed model (GLMM), including the binomial-normal model (BN) and Hypergeometric-normal model (HNM), which can be used to achieve random effects meta-analysis of rare binary data. This paper introduces the model in detail and its implementation in SAS software with examples to provide relevant SAS code.
ObjectiveTo explore the nature of micromovement and the biomechanical staging of fracture healing.MethodsThrough literature review and theoretical analysis, the difference in micromovement research was taken as the breakthrough point to try to provide a new understanding of the role of micromovement and the mechanical working mode in the process of fracture healing.ResultsThe process of fracture healing is the process of callus generation and connection. The micromovement is the key to start the growth of callus, and the total amount of callus should be matched with the size of the fracture space. The strain at the fracture end is the key to determine the callus connection. The strain that can be tolerated by different tissues in the fracture healing process will limit the micromovement. According to this, the fracture healing process can be divided into the initiation period, perfusion period, contradiction period, connection period, and physiological period, i.e., the biomechanical staging of fracture healing.ConclusionBiomechanical staging of fracture healing incorporates important mechanical parameters affecting fracture healing and introduces the concepts of time and space, which helps to understand the role of biomechanics, and its significance needs further clinical test and exploration.
ObjectiveTo explore the correlation between cognitive function and diffusion tensor imaging (DTI) in children with self-limited epilepsy with centrotemporal spikes (SelECTS). Methods A total of 28 children with SelECTS who visited our hospital from June 2020 to December 2022 were selected as the SelECTS group. An additional 28 healthy children of similar age and gender were selected as the control group. Cognitive function was assessed using the Wechsler Intelligence Scale for Children (WISC). The SelECTS group also underwent cranial DTI. The results of the WISC were then combined with DTI values for correlation analysis. Results Children in the SelECTS group exhibited varying degrees of cognitive deficits. Their full-scale IQ and verbal IQ were significantly lower than those of the control group (P<0.05). Specific cognitive domains, including classification, verbal comprehension, block design, knowledge, and comprehension, also showed significantly lower scores compared to the control group (P<0.05). DTI revealed significant microstructural changes in multiple regions of interest in the SelECTS group (P<0.05), and these changes were correlated with the results of several cognitive function tests. Conclusion Children with SelECTS have certain cognitive deficits. There is evidence of occult damage in brain white matter, and cognitive function is correlated with damage in specific brain regions.
Longitudinal data had intrinsic correlation problems at different time points, and traditional meta-analysis techniques cannot resolve this problem. Regression coefficients based on multi-level models can fully consider the correlations of longitudinal data at various time points. This paper uses SAS software to perform multi-level regression coefficient model meta-analysis and provides programming code which is simple and easy to operate.
Despite the rapid development of meta-analysis technology, there were currently no consolidation technology for longitudinal data. The meta-analysis model based on the generalized linear mixed-effects model can fully encapsulate the correlation between various time points and accurately estimate the final combined effect, which is an ideal model for longitudinal-data meta-analysis. Through example data, this paper used SAS software to realize longitudinal-data meta-analysis and provided programming codes.
ObjectiveTo evaluate the feasibility and effectiveness of percutaneous screwdriver rod-assisted closed reduction in the treatment of valgus-impacted femoral neck fractures. MethodsBetween January 2021 and May 2022, 12 patients with the valgus-impacted femoral neck fractures were treated with percutaneous screwdriver rod-assisted closed reduction and femoral neck system (FNS) internal fixation. There were 6 males and 6 females with a median age of 52.5 years (range, 21-63 years). The fractures were caused by traffic accident in 2 cases, falling in 9 cases, and falling from height place in 1 case. All were unilateral closed femoral neck fractures, including 7 on the left side and 5 on the right side. The time from injury to operation was 1-11 days, with an average of 5.5 days. The fracture healing time and postoperative complications were recorded. The quality of fracture reduction was evaluated by Garden index. At last follow-up, Harris score was used to evaluate the hip joint function, also the shortening of femoral neck was measured. ResultsAll the operations were successfully completed. After operation, the incision fat liquefaction occurred in 1 case, which healed after enhanced dressing change, and the other patients’ incisions healed by first intention. All patients were followed up 6-18 months, with an average of 11.7 months. The X-ray film reexamination showed that the quality of fracture reduction was grade Ⅰ in 10 cases and grade Ⅱ in 2 cases according to the Garden index. All fractures reached bony union, and the healing time was 3-6 months, with an average of 4.8 months. At last follow-up, the femoral neck was shortened by 1-4 mm, with an average of 2.1 mm. No internal fixation failure or osteonecrosis of the femoral head occurred during follow-up. At last follow-up, the hip Harris score was 85-96, with an average of 92.4; 10 cases were rated as excellent and 2 were good. Conclusion The percutaneous screwdriver rod-assisted closed reduction can effectively reduce the valgus-impacted femoral neck fracture. It has the advantages of simple operation, effective, and less impact on blood supply.
Objective To investigate the in vitro antioxidant and osteogenic induction capabilities of calcium phosphate nanoflowers (hereinafter referred to as nanoflowers) at different concentrations. Methods Nanoflowers were prepared using gelatin, tripolyphosphate, and calcium chloride. Their morphology, microstructure, elemental composition and distribution, diameter, and molecular constitution were characterized using scanning electron microscopy, transmission electron microscopy, Fourier transform infrared spectroscopy, and energy-dispersive spectroscopy. Femurs and tibias were harvested from twelve 4-week-old Sprague Dawley rats, and bone marrow-derived mesenchymal stem cells (BMSCs) were isolated and cultured using the whole bone marrow adherent method, followed by passaging. The third passage cells were identified as stem cells by flow cytometry and then co-cultured with nanoflowers at concentrations of 0, 0.4, 0.8, 1.2, 1.6, 2.0, 2.4, 2.8, 3.2, and 3.6 mg/mL. Cell counting kit 8 (CCK-8) assay was performed to screen for the optimal concentration that demonstrated the best cell viability, which was subsequently used as the experimental concentration for further studies. After co-culturing BMSCs with the screened concentration of nanoflowers, the biocompatibility of the nanoflowers was verified through live/dead cell staining, scratch assay, and cytoskeleton staining. The antioxidant capacity was assessed by using reactive oxygen species (ROS) fluorescence staining. The in vitro osteoinductive ability was evaluated via alkaline phosphatase (ALP) staining, alizarin red staining, and immunofluorescence staining of osteocalcin (OCN) and Runt-related transcription factor 2 (RUNX2). All the above indicators were compared with the control group of normally cultured BMSCs without the addition of nanoflowers.Results Scanning electron microscopy revealed that the prepared nanoflowers exhibited a flower-like structure; transmission electron microscopy scans discovered that the nanoflowers possessed a multi-layered structure, and high-magnification images displayed continuous atomic arrangements, with the nanoflower diameter measuring (2.00±0.25) μm; energy-dispersive spectroscopy indicated that the nanoflowers contained elements such as C, N, O, P, and Ca, which were uniformly distributed across the flower region; Fourier transform infrared spectroscopy analyzed the absorption peaks of each component, demonstrating the successful preparation of the nanoflowers. Through CCK-8 screening, the concentrations of 0.8, 1.2, and 1.6 mg/mL were selected for subsequent experiments. The live/dead cell staining showed that nanoflowers at different concentrations exhibited good cell compatibility, with the 1.2 mg/mL concentration being the best (P<0.05). The scratch assay results indicated that the cell migration ability in the 1.2 mg/mL group was superior to the other three groups (P<0.05). The cytoskeleton staining revealed that the cell morphology was well-extended in all concentration groups, with no significant difference compared to the control group. The ROS fluorescence staining demonstrated that the ROS fluorescence in all concentration groups decreased compared to the control group after lipopolysaccharide induction (P<0.05), with the 1.2 mg/mL group showing the weakest fluorescence. The ALP staining showed blue-purple nodular deposits around the cells in all groups, with the 1.2 mg/mL group being significantly more prominent. The alizarin red staining displayed orange-red mineralized nodules around the cells in all groups, with the 1.2 mg/mL group having more and denser nodules. The immunofluorescence staining revealed that the expressions of RUNX2 and OCN proteins in all concentration groups increased compared to the control group, with the 1.2 mg/mL group showing the strongest protein expression (P<0.05). Conclusion The study successfully prepares nanoflowers, among which the 1.2 mg/mL nanoflowers exhibits excellent cell compatibility, antioxidant properties, and osteogenic induction capability, demonstrating their potential as an artificial bone substitue material.