Roux-en-Y Gastric Bypass Improves Insulin Sensitivity in Obese Rats with Type 2 Diabetes Mellitus by Regulating the Grin3a/AMPK Signal Axis in Hypothalamic Arcuate Nucleus.

Objective: The objective of this study was to explore the effects and related mechanisms of Roux-en-Y gastric bypass (RYGB) on insulin sensitivity in obese rats with type 2 diabetes mellitus (T2DM). Methods: The obese T2DM rat model was constructed by feeding a high-fat diet and injecting streptozotocin (STZ), and treated with RYGB. Grin3a shRNA was injected into the bilateral hypothalamic arcuate nucleus (ARC) to knockdown the Grin3a expression on T2DM rats. Eight weeks after operation, the body weight, fasting blood glucose (FBG), fasting serum insulin (FSI), homeostatic model assessment of insulin resistance (HOMA-IR), and plasma triglyceride (TG) levels were assessed. Hematoxylin & eosin (H&E) staining was adopted to observe the white adipose tissue (WAT) of rats. Western blot and qRT-PCR were used to detect the expression of Grin3a, adenosine 5' monophosphate-activated protein kinase (AMPK) and p-AMPK in ARC of rats. Later, the plasmid over-expressing or knocking down Grin3a was transfected into differentiated 3T3-L1 adipocytes, and the TG level and the formation of lipid droplets in adipocyte were assessed by TG kit and oil red O staining. The expression of lipogenic transcription factors in cells was detected by qRT-PCR. Results: RYGB reduced FBG, FSI, HOMA-IR and plasma TG levels in T2DM rats while increasing Grin3a expression and p-AMPK/AMPK ratio in ARC. Knockdown of Grin3a not only reversed the decrease of FBG, FSI, HOMA-IR and plasma TG levels in T2DM rats induced by RYGB, but also reversed the up-regulation of p-AMPK/AMPK ratio in ARC affected by RYGB. Moreover, knocking down Grin3a significantly increased the TG level, promoted the formation of lipid droplets and up-regulated the expressions of lipogenic transcription factors in adipocytes. Conclusion: RYGB improved the insulin sensitivity, reduced the plasma TG level and lessens the fat accumulation in obese T2DM rats by regulating the Grin3a/AMPK signal in ARC.

The regulatory effect and molecular mechanism of lncRNA Gm10451 on islet cell dysfunction in children with diabetes.

The dysfunction of islet ß-cells is one of the causes of diabetes, and lncRNA Gm10451 is also a participant in the occurrence and the development of various diseases. This study was carried out to reveal the correlation within ß-cells and Gm10451. Our study was started with the cellular cultivation of MIN6 cells in vitro, where this islet ß-cell line was randomly divided into the groups of control, hyperglycemia, Gm10451 siRNA tansfection, and Gm10451 tansfection. Of all these treatments, cells in the groups of Gm10451 siRNA tansfection and Gm10451 tansfection were given with lentiviral transfection under hyperglycemia condition. Further explorations were established using PCR assay and MTT method to evaluate Gm10451 expression and estimate cellular proliferation. It ended up with the enzyme-linked immunosorbent assay (ELISA) to assess Caspase 3 activity, superoxide dismutase (SOD) activity, and reactive oxygen species (ROS) content and the secretion of IL-10 and IL-1. It was found that Gm10451 expression in MIN6 cells under hyperglycemia cultivation was notably higher than the control group; likewise, a transfection with the lentivirus of Gm10451 also resulted in the upregulation of Gm10451 expression, succeeded with inhibiting cellular proliferation, enhancing Caspase 3 activity, and decreasing SOD activity. In the lentivirus transfection groups, transfection of Gm10451 elevated the ROS content and promoted IL-1 expression, and it also decreased both IL-10 expression and insulin secretion, leading to a consequence of statistically significant difference in contrast to the high-glucose group; on the contrary, transfection of Gm10451 siRNA in a high-glucose environment downregulated the expression of Gm10451 and inversed those change before, whose results were statistically significant when compared with the high-glucose group. Hyperglycemia promotes the expression of Gm10451. Targeting inhibition toward Gm10451 alleviates cellular apoptosis and the oxidative stress of islet cells, promoting proliferation and insulin secretion of islet cells.

The Association of lncRNA and mRNA Changes in Adipose Tissue with Improved Insulin Resistance in Type 2 Obese Diabetes Mellitus Rats after Roux-en-Y Gastric Bypass.

Objective: Roux-en-Y gastric bypass (RYGB) has shown good effects in improving obesity and type II diabetes mellitus (T2DM), but the underlying mechanisms remain unclear. This study explored the changes of related lncRNAs, mRNAs, and signaling pathways in white adipose tissue of T2DM rats after RYGB based on RNA-Seq sequencing, with the aim to provide a theoretical basis for RYGB treatment. Methods: T2DM rat models were established by continuous feeding with a high-fat diet and injection of streptozotocin (STZ), after which they underwent RYGB or sham surgery. After the surgery, their body weight was measured weekly. Their fasting blood glucose (FBG) and fasting serum insulin (FSI) were also measured. A homeostasis model assessment of insulin resistance (HOMA-IR) was calculated at weeks 0, 8, and 12. Besides, white adipose tissue of T2DM rats was collected for RNA-Seq sequencing and validated by qRT-PCR. A series of bioinformatics analyses, such as differential expression genes (DEGs) screening, was performed. GO and KEGG functional enrichment analysis and protein-protein interaction (PPI) network construction were conducted based on the sequencing data. Results: RYGB surgery could significantly inhibit the weight growth rate and decrease the FBG, FSI, and HOMA-IR of T2DM rats. Bioinformatics analysis of RNA sequencing (RNA-Seq) results revealed that 87 DE- lncRNAs (49 upregulated and 38 downregulated) and 1,824 DEGs (896 upregulated and 928 downregulated) were present in between the RYGB group and Sham group. GO and KEGG analysis showed that the target genes of DEGs and differentially expressed lncRNAs (DE-lncRNAs) were mainly associated with amino acid metabolism, fatty acid metabolism, channel activity, and other processes. In addition, the PPI network diagram also displayed that genes such as Fasn, Grin3a, and Nog could be key genes playing a role after RYGB. qRT-PCR showed that the expression level of Grin3a in the RYGB group was significantly increased compared with the Sham group, while the expression of Fasn and Nog was significantly decreased, which was consistent with the sequencing results. Conclusion: Using RNA-Seq sequencing, this study revealed the changes of related lncRNAs, mRNAs, and signaling pathways in the white adipose tissue of T2DM rats after RYGB and identified Fasn, Grin3a, and Nog as potential key genes to function after RYGB.

Effect of vision loss on plasticity of the head and neck proprioception.

AIM: To investigate whether head and neck proprioception and motor control could be compensatory enhanced by long-term vision loss or impairment. METHODS: Individuals who were blind, low vision or sighted were included in the study, which would undergo the head repositioning test (HRT). The constant error (CE), absolute error (AE), variable error (VE) and root mean square error (RMSE) of each subject were statistically analyzed. Data were analyzed using the SAS 9.4. Tukey-Kramer for one-way ANOVA was used for comparison of blind, low vision, and sighted subjects, as well as to compare subjects with balanced vision, strong vision in the left eye and strong vision in the right eye. Independent sample t-test was used to compare subjects with congenital blindness and acquired blindness, as well as left and right hand dominance subjects. RESULTS: A total of 90 individuals (25 blind subjects, 31 low vision subjects, and 34 sighted subjects) were included in the study. Among the blind subjects, 14 cases had congenital blindness and 11 cases had acquired blindness. Among the blind and low vision subjects, 21 cases had balanced binocular vision, 17 cases had strong vision in the left eye and 18 cases had strong vision in the right eye. Among all subjects, 11 cases were left hand dominance, and 79 cases were right hand dominance. There were significant differences in AE, VE, and RMSE in head rotation between blind, low vision, and sighted subjects (P<0.01), in AE, VE, and RMSE between blind and sighted (P<0.01), and in VE and RMSE between low vision and sighted (P<0.05). No significant difference between blind and low vision (P>0.05). Significant differences in CE and AE of head right rotation and CE of general head rotation between congenital and acquired (P<0.05). No significant differences between left and right hand dominance and in balance or not of binocular vision (P>0.05). CONCLUSION: Long-term vision loss or impairment does not lead to compensatory enhancement of head and neck proprioception and motor control. Acquired experience contributes to HRT performance in the blind and has long-lasting effects on plasticity in the development of proprioception and sensorimotor control.

Correlative analysis of gene mutation and clinical features in patients with non-small cell lung cancer.

BACKGROUND: Lung cancer is the main reason for death associated with cancer all over the world. In most cases of non-small cell lung cancer (NSCLC), patients only express one type of gene mutation, each gene mutation population has different clinicopathological features, and each is expressed differently in different regions of the population. At present, there are few studies on multiple driver genes and clinicopathological features of the population in Hunan, China. METHODS: From February 2016 to December 2017, the Department of Geriatric Respiratory Medicine of Xiangya Hospital of Central South University diagnosed 113 cases of NSCLC. Genetic testing of next-generation sequencing (NGS) was completed, and it conformed to the inclusion criteria. All cases were pathologically confirmed as NSCLC, with the tumor staging being based on the 8th edition of TNM classification. RESULTS: In this study, we included a total of 113 NSCLC cases, including 78 males and 35 females. Histological distributions were mainly adenocarcinoma (ADC, 78.76%) and squamous cell carcinoma (SCC, 21.24%). We found 71 cases had gene-mutations. There was one concurrent mutation of ALK and ROS1, one concurrent mutation of epidermal growth factor receptor (EGFR) and BRAF, one concurrent mutation of EGFR and MET, one concurrent mutation of MET and BRAF, and one concurrent mutation of EGFR and KRAS; there were two cases of concurrent mutation of EGFR and ERBB2. The distribution of each of the mutated genes was as follows: EGFR, 62.82%; ALK, 8.97%; ROS1, 5.13%; MET, 5.13%; ERBB2, 5.13%; RET, 0.00%; BRAF, 2.56%; KRAS, 10.26%. Our study found that in patients with EGFR mutation, the mutation rate of males was 32.05%, and the rate in females was 68.57% (P<0.01); the mutation rate in people aged 60 or above was 40.00% while for those aged lower than 60 it was 46.55% (P>0.05); the mutation rate of ADC was 52.81% and in SCC was 8.33% (P<0.01); the mutation rate in smokers was 32.84% and in non-smokers was 58.70% (P<0.05); the mutation rate in patients of IV stage was 47.37% and the rate in patients of non-IV stage was 22.22% (P>0.05). Our study found that among patients with ALK/ROS1/MET/ERBB2/BRAF/KRAS mutations, the mutation rate in men was 7.69%, 2.60%, 3.85%, 2.56%, 0.00%, and 8.97% respectively, and for females it was 2.86%, 5.71%, 2.86%, 5.71%, 5.71%, and 2.86% respectively; the mutation rate in patients aged 60 and older was 3.64%, 5.45%, 3.64%, 1.82%, 1.82%, and 9.09% respectively; the rate in patients aged lower 60 was 8.62%, 1.72%, 3.45%, 5.17%, 1.72%, and 5.17% respectively; the mutation rate of ADC was 6.74%, 3.37%, 3.37%, 4.49%, 2.25%, and 6.74% respectively, while for SCC, it was 4.17%, 4.17%, 4.17%, 0.00%, 0.00%, and 8.33% respectively; the mutation rate in smokers was 8.96%, 1.49%, 4.48%, 1.49%, 0.00%, and 10.45% respectively, while in non-smokers, it was 2.17%, 6.52%, 2.17%, 6.52%, 4.35%, and 2.17% respectively; the mutation rate in patients of IV stage was 7.37%, 4.21%, 2.11%, 4.21%, 2.11%, and 7.37% respectively, and in patients of non-IV stage, it was 0.00%, 0.00%, 11.11%, 0.00%, 0.00%, and 5.56% respectively. In ALK/ROS1/MET/ERBB2/BRAF/KRAS mutations, there was no statistically significant difference in gender, age, tissue type, smoking history, and stage. Our research shows that the distribution of each mutant type of EGFR mutation was as follows: exon 2, 1/74 (1.35%); exon 4, 1/74 (1.35%); exon 6, 1/74 (1.35%); exon 18, 1/74 (1.35%); exon 19, 25/74 (33.78%); exon 20, 12/74 (16.22%); exon 21, 19/74 (25.68%); exon 22, 1/74 (1.35%); and EGFR amplification, 13/74 (17.57%). CONCLUSIONS: (I) EGFR mutation was more common in non-smoking female patients with ADC and had no significant correlation with age and stage. (II) EGFR mutations were mainly concentrated in exon 19, 20, 21, and EGFR amplification. There was no significant statistical difference between mutations in exons 19, 20, 21, EGFR gene amplification and clinical features. (III) There was no statistically significant difference in the ALK/ROS1/MET/ERBB2/BRAF/KRAS mutations with gender, age, tissue type, smoking history, and tumor stage.

Early Experience with Reduction of Unstable Pelvic Fracture Using a Computer-Aided Reduction Frame.

PURPOSE: The optimal closed reduction technique for unstable pelvic fractures remains controversial. The purpose of this study is to verify the effectiveness and report early experiences with the reduction of unstable pelvic fractures using a computer-aided pelvic reduction frame. METHODS: From January 2015 to August 2016, a total of 10 patients with unilateral unstable pelvic fractures were included in this study. The surgical reduction procedure was based on the protocol of the computer-aided pelvic reduction frame that we proposed in a previous work. The quality of the reductions achieved using this system was evaluated with residual translational and rotational differences between the actual and virtual reduction positions of pelvis. The duration of the operation was recorded for quality control. RESULTS: The mean times required to set up the frame, to complete the virtual surgery simulation, and to reduce the unstable pelvic fractures were 10.3, 20.9, and 7.5 min, respectively. The maximum residual translational and rotational displacements were less than 6.5 mm and 3.71 degrees, respectively. CONCLUSIONS: This computer-aided reduction frame can be a useful tool for the speedy and accurate reduction of unstable pelvic fractures. Further clinical studies should be conducted with larger patient samples to verify its safety and efficacy.

Cell cycle and complement inhibitors may be specific for treatment of spinal cord injury in aged and young mice: Transcriptomic analyses.

Previous studies have reported age-specific pathological and functional outcomes in young and aged patients suffering spinal cord injury, but the mechanisms remain poorly understood. In this study, we examined mice with spinal cord injury. Gene expression profiles from the Gene Expression Omnibus database (accession number GSE93561) were used, including spinal cord samples from 3 young injured mice (2-3-months old, induced by Impactor at Th9 level) and 3 control mice (2-3-months old, no treatment), as well as 2 aged injured mice (15-18-months old, induced by Impactor at Th9 level) and 2 control mice (15-18-months old, no treatment). Differentially expressed genes (DEGs) in spinal cord tissue from injured and control mice were identified using the Linear Models for Microarray data method, with a threshold of adjusted P < 0.05 and |logFC(fold change)| > 1.5. Protein-protein interaction networks were constructed using data from the STRING database, followed by module analysis by Cytoscape software to screen crucial genes. Kyoto encyclopedia of genes and genomes pathway and Gene Ontology enrichment analyses were performed to investigate the underlying functions of DEGs using Database for Annotation, Visualization and Integrated Discovery. Consequently, 1,604 and 1,153 DEGs were identified between injured and normal control mice in spinal cord tissue of aged and young mice, respectively. Furthermore, a Venn diagram showed that 960 DEGs were shared among aged and young mice, while 644 and 193 DEGs were specific to aged and young mice, respectively. Functional enrichment indicates that shared DEGs are involved in osteoclast differentiation, extracellular matrix-receptor interaction, nuclear factor-kappa B signaling pathway, and focal adhesion. Unique genes for aged and young injured groups were involved in the cell cycle (upregulation of PLK1) and complement (upregulation of C3) activation, respectively. These findings were confirmed by functional analysis of genes in modules (common, 4; aged, 2; young, 1) screened from protein-protein interaction networks. Accordingly, cell cycle and complement inhibitors may be specific treatments for spinal cord injury in aged and young mice, respectively.

The PI3K/Akt/FOXO3a pathway regulates regeneration following spinal cord injury in adult rats through TNF-α and p27kip1 expression.

The aim of the present study was to elucidate the expression and role of the phosphatidylinositol 3­kinase (PI3K)/Akt/forkhead box O3 (FOXO3a) pathway in the regeneration of the spinal cord following spinal cord injury (SCI), and its regulatory effect on tumor necrosis factor (TNF)-α and cyclin-dependent kinase inhibitor 1B (p27kip1) expression. Firstly, in a Sprague-Dawley rat model of SCI, western blot analysis revealed that the protein levels of PI3K, phosphorylated Akt and FOXO3a were markedly inhibited compared with those in the sham control group. In vitro experiments were also conducted, in which primary dissociated cultures of rat dorsal spinal cord cells were induced with lipopolysaccharide (LPS; 4 µg/ml). The downregulation of PI3K using LY294002 markedly suppressed cell viability, reduced the protein levels of FOXO3a and p27kip1, and increased TNF-α protein production in the LPS-induced spinal cord cells. In addition, when the LPS-induced spinal cord cells were infected with FOXO3a adenoviral vectors, the overexpression of FOXO3 markedly promoted cell proliferation, activated p27kip1 protein levels and inhibited TNF-α protein production in the spinal cord cells. These results suggest that the PI3K/Akt/FOXO3a pathway regulates regeneration following SCI in adult rats via its modulatory effects on TNF-α and p27kip1 expression.

A mathematical method for precisely calculating the radiographic angles of the cup after total hip arthroplasty.

We established a mathematical method to precisely calculate the radiographic anteversion (RA) and radiographic inclination (RI) angles of the acetabular cup based on anterior-posterior (AP) pelvic radiographs after total hip arthroplasty. Using Mathematica software, a mathematical model for an oblique cone was established to simulate how AP pelvic radiographs are obtained and to address the relationship between the two-dimensional and three-dimensional geometry of the opening circle of the cup. In this model, the vertex was the X-ray beam source, and the generatrix was the ellipse in radiographs projected from the opening circle of the acetabular cup. Using this model, we established a series of mathematical formulas to reveal the differences between the true RA and RI cup angles and the measurements results achieved using traditional methods and AP pelvic radiographs and to precisely calculate the RA and RI cup angles based on post-operative AP pelvic radiographs. Statistical analysis indicated that traditional methods should be used with caution if traditional measurements methods are used to calculate the RA and RI cup angles with AP pelvic radiograph. The entire calculation process could be performed by an orthopedic surgeon with mathematical knowledge of basic matrix and vector equations.

New classification of lunate fossa fractures of the distal radius.

BACKGROUND: A die-punch fracture is a depression fracture of the lunate fossa of the distal radius. We propose a morphological classification of die-punch fractures that includes five types: center depression fractures, vertical depression fractures, volar depression fractures, dorsal depression fractures, and double die-punch fractures. METHODS: The radiographs of 112 die-punch fractures treated between January 2005 and January 2015 were retrospectively reviewed. The clinical images were examined independently for two rounds by six orthopedists with different clinical experiences: two residents, two attending physicians, and two consultants. A category-specific kappa score and a kappa score for more than two observers were analyzed. We used Cohen's kappa to test intraobserver variation. RESULTS: The kappa score for interobserver reliability was 0.69 for the first round and 0.70 for the second round. The intraclass correlations were 0.65 and 0.63, respectively. Intraobserver reproducibility using Cohen's kappa test was satisfactory. All of the results indicated a kappa value >0.4, suggesting good agreement within, as well as between, observers. CONCLUSIONS: The outcome was assessed using kappa statistics, which showed good interobserver reliability and intraobserver reproducibility.

Establishment of a rat model of chronic thoracolumbar cord compression with a flat plastic screw.

Previous studies of animal models of chronic mechanical compression of the spinal cord have mainly focused on cervical and thoracic lesions, but few studies have investigated thoracolumbar injury. The specific pathophysiological mechanism of chronic thoracolumbar cord injury has not yet been elucidated. The purpose of this study was to improve animal models of chronic thoracolumbar cord compression using the progressive screw. A custom-designed flat plastic screw was implanted in the spinal cord between thoracic vertebrae 12 and lumbar 1 of rats. The screw was tightened one complete turn (0.5 mm) every 7 days for 4 weeks to create different levels of chronic spinal cord compression. Following insertion of the screw, there was a significant decline in motor function of the hind limbs, and severe stenosis of micro-computed tomography parameters in the spinal cord. Cortical somatosensory evoked potential amplitudes were reduced remarkably, and latencies were prolonged at 30 minutes after surgery. The loss of motor neurons in the gray matter was marked. Demyelination and cavitation were observed in the white matter. An appropriate rat model of chronic thoracolumbar cord compression was successfully created using the progressive screw compression method, which simulated spinal cord compression injury.

Evaluation of Elastic Stiffness in Healing Achilles Tendon After Surgical Repair of a Tendon Rupture Using In Vivo Ultrasound Shear Wave Elastography.

BACKGROUND There has been no published report assessing the mechanical properties of a repaired Achilles tendon after surgery using shear wave elastography (SWE). The aim of this study was to investigate the changes in mechanical properties of the healing Achilles tendon after surgical repair of a tendon rupture using ultrasound SWE and how these changes correlate with tendon function. MATERIAL AND METHODS Twenty-six patients who underwent surgical repair for Achilles tendon rupture were examined with ultrasound SWE coupled with a linear array transducer (4-15 MHz). The elasticity values of the repaired Achilles tendon in a longitudinal view were measured at 12, 24, and 48 weeks postoperatively. Functional outcomes were assessed with the American Orthopedic Foot and Ankle Society (AOFAS) rating system at 12, 24, and 48 weeks postoperatively. General linear regression analysis and correlation coefficients were used to analyze the relationship between elasticity and the AOFAS score. RESULTS There were significant differences with respect to the mean elasticity values and functional scores of the repaired Achilles tendon at 12, 24, and 48 weeks postoperatively (all P<0.05). Tendon function was positively correlated with the elasticity of the repaired Achilles tendon (P=0.0003). CONCLUSIONS Our findings suggest that SWE can provide biomechanical information for evaluating the mechanical properties of healing Achilles tendon and predict Achilles tendon function.

Experimental study on treatment of acetabular anterior column fractures: applyment of a minimally invasive percutaneous lag screw guide apparatus.

BACKGROUND: The aim of this study was to design a new minimally invasive percutaneous lag screw guide apparatus and to verify its adjuvant treatment of acetabular anterior column fracture on pelvis specimens. METHODS: This guide apparatus was self-developed based on the principles of "two points form a line" and "Rectangle". Using C-arm fluoroscopy, this guide apparatus was used to conduct minimally invasive percutaneous lag screw internal fixation of acetabular anterior column fractures. Ten hollow lag screws were placed into 5 pelvis specimens. RESULT: Result showed no sign of any screws puncturing the cortex or entering into the hip joint on radiological assessment. The cross-section reconstructed vertical distance to the screw, on the cross-section acetabular notch and the cross-section of the screw where the distance of between the screw and the iliopectineal line's arc roof was at its shortest, indicate that at all points (T, R-r) under the line with an inclination of 1 (namely T = R-r) the screw is within the cortex and does not puncture the acetabula anterior column or enter into the hip joint. CONCLUSIONS: We may conclude that this self-developed guide apparatus solves the screw precision problem during the treatment of acetabular anterior column fractures through a minimally invasive percutaneous lag screw.

Effect of Negative Pressure on Proliferation, Virulence Factor Secretion, Biofilm Formation, and Virulence-Regulated Gene Expression of Pseudomonas aeruginosa In Vitro.

Objective. To investigate the effect of negative pressure conditions induced by NPWT on P. aeruginosa. Methods. P. aeruginosa was cultured in a Luria-Bertani medium at negative pressure of -125 mmHg for 24 h in the experimental group and at atmospheric pressure in the control group. The diameters of the colonies of P. aeruginosa were measured after 24 h. ELISA kit, orcinol method, and elastin-Congo red assay were used to quantify the virulence factors. Biofilm formation was observed by staining with Alexa Fluor® 647 conjugate of concanavalin A (Con A). Virulence-regulated genes were determined by quantitative RT-PCR. Results. As compared with the control group, growth of P. aeruginosa was inhibited by negative pressure. The colony size under negative pressure was significantly smaller in the experimental group than that in the controls (p < 0.01). Besides, reductions in the total amount of virulence factors were observed in the negative pressure group, including exotoxin A, rhamnolipid, and elastase. RT-PCR results revealed a significant inhibition in the expression level of virulence-regulated genes. Conclusion. Negative pressure could significantly inhibit the growth of P. aeruginosa. It led to a decrease in the virulence factor secretion, biofilm formation, and a reduction in the expression level of virulence-regulated genes.

Computer-aided pelvic reduction frame for anatomical closed reduction of unstable pelvic fractures.

Traditional closed reductions of unstable pelvic fractures are mainly performed by surgeons using manual manipulation and subjective verification based on intra-operative roentgenography. It is difficult to perform an accurate closed reduction because of a lack of adequate knowledge of the displacement patterns and an inability to apply the reduction in correct direction. Using the concept of the remote center of motion mechanism and computer-aided design software, we developed a pelvic reduction frame for use in anatomical closed reductions of unstable pelvic fractures. With three-dimensional reconstruction technique and the matrix algorithm, the spatial orientation of the displaced hemipelvis can be calculated and deconstructed into several rotational and translational movements that can be completed with the frame. To verify the accuracy of this system, the rotations were repeated 10 times in arbitrary degrees and directions. After the matrix is calculated, the displaced hemipelvis can be reduced to the anatomical position using our frame. The maximum residual translational and rotational displacements were less than 5 mm and 4 degrees, which indicated the accuracy of this system. The maximum average residual translation and rotation were 1.87 mm in Z-axis (ranging: 4.63-0.1 mm) and 1.1 degrees around Y-axis (ranging: 3.81-0.13 degrees), respectively. Only the Z-axial translation showed a statistically significant difference (p < 0.05). In conclusion, the proposed pelvic reduction frame could be a useful tool for the anatomical reduction of unstable pelvic fractures.

Three-Dimensional Analysis of the Curvature of the Femoral Canal in 426 Chinese Femurs.

PURPOSE: The human femur has long been considered to have an anatomical anterior curvature in the sagittal plane. We established a new method to evaluate the femoral curvature in three-dimensional (3D) space and reveal its influencing factors in Chinese population. METHODS: 3D models of 426 femurs and the medullary canal were constructed using Mimics software. We standardized the positions of all femurs using 3ds Max software. After measuring the anatomical parameters, including the radius of femoral curvature (RFC) and banking angle, of the femurs using the established femur-specific coordinate system, we analyzed and determined the relationships between the anatomical parameters of the femur and the general characteristics of the population. RESULTS: Pearson's correlation analyses showed that there were positive correlations between the RFC and height (r = 0.339, p < 0.001) and the femoral length and RFC (r = 0.369, p < 0.001) and a negative correlation between the femoral length and banking angle (r = -0.223, p < 0.001). Stepwise linear regression analyses showed that the most relevant factors for the RFC and banking angle were the femoral length and gender, respectively. CONCLUSIONS: This study concluded that the banking angle of the femur was significantly larger in female than in male.

A computer aided measurement method for unstable pelvic fractures based on standardized radiographs.

BACKGROUND: To set up a method for measuring radiographic displacement of unstable pelvic ring fractures based on standardized X-ray images and then test its reliability and validity using a software-based measurement technique. METHODS: Twenty-five patients that were diagnosed as AO/OTA type B or C pelvic fractures with unilateral pelvis fractured and dislocated were eligible for inclusion by a review of medical records in our clinical centre. Based on the input pelvic preoperative CT data, the standardized X-ray images, including inlet, outlet, and anterior-posterior (AP) radiographs, were simulated using Armira software (Visage Imaging GmbH, Berlin, Germany). After representative anatomic landmarks were marked on the standardized X-ray images, the 2-dimensional (2D) coordinates of these points could be revealed in Digimizer software (Model: Mitutoyo Corp., Tokyo, Japan). Subsequently, we developed a formula that indicated the translational and rotational displacement patterns of the injured hemipelvis. Five separate observers calculated the displacement outcomes using the established formula and determined the rotational patterns using a 3D-CT model based on their overall impression. We performed 3D reconstruction of all the fractured pelvises using Mimics (Materialise, Haasrode, Belgium) and determined the translational and rotational displacement using 3-matic suite. The interobserver reliability of the new method was assessed by comparing the continuous measure and categorical outcomes using intraclass correlation coefficient (ICC) and kappa statistic, respectively. RESULT: The interobserver reliability of the new method for translational and rotational measurement was high, with both ICCs above 0.9. Rotational outcome assessed by the new method was the same as that concluded by 3-matic software. The agreement for rotational outcome among orthopaedic surgeons based on overall impression was poor (kappa statistic, 0.250 to 0.426). Compared with the 3D reconstruction outcome, the interobserver reliability of the formula method for translational and rotational measures was perfect with both ICCs more than 0.9. CONCLUSIONS: The new method for measuring displacement using a formula was reliable, and could minimise the measurement errors and maximise the precision of pelvic fracture description. Furthermore, this study was useful for standardising the operative plan and establishing a theoretical basis for robot-assisted pelvic fracture surgery based on 2-D radiographs.

Three-Dimensional Analysis of the Characteristics of the Femoral Canal Isthmus: An Anatomical Study.

PURPOSE: To establish a new approach for measuring and locating the femoral intramedullary canal isthmus in 3-dimensional (3D) space. METHODS: Based on the computed tomography data from 204 Chinese patients, 3D models of the whole femur and the corresponding femoral isthmus tube were reconstructed using Mimics software (Materialise, Haasrode, Belgium). The anatomical parameters of the femur and the isthmus, including the femur length and radius, and the isthmus diameter and height, were measured accordingly. RESULTS: The mean ratio of the isthmus height versus the femoral height was 55 ± 4.8%. The mean diameter of the isthmus was 10.49 ± 1.52 mm. The femoral length, the isthmus diameter, and the isthmus tube length were significantly larger in the male group. Significant correlations were observed between the femoral length and the isthmus diameter (r = 0.24, p < 0.01) and between the femoral length and the isthmus height (r = 0.6, p < 0.01). Stepwise linear regression analyses demonstrated that the femoral length and radius were the most important factors influencing the location and dimension of the femoral canal isthmus. CONCLUSION: The current study developed a new approach for measuring the femoral canal and for optimization of customer-specific femoral implants.