Abstract
Background
In nerve transfer for peripheral nerve injury, it is sometimes necessary to suture size-mismatched nerves. In 1993, a favorable suture method called the Ochiai suture method for ...size-mismatched nerve transfer was reported. However, there is currently a lack of substantial evidence beyond the original report. Therefore, this study aimed to verify the advantages of using the Ochiai suture method for size-mismatched nerve transfer.
Methods
A total of 18 rats were evaluated in this study and randomly divided into two groups. All rats underwent femoral to sciatic nerve transfer. Specifically, group A (
n
= 10) underwent the Ochiai suture method, while group B (
n
= 8) underwent the perineural suture method. After 12 weeks postoperatively, we conducted the sciatic functional index (SFI) test, measured muscle wet-weight, and performed histological evaluations. All data were compared between the two groups, with Welch’s t test for normally distributed data and Mann-Whitney's U test for non-normally distributed data. Statistical significance was set at
p
< 0.05.
Results
The mean number of axons was significantly greater in group A than in group B at 5 mm distal to the stump (
p
= 0.04). Additionally, the average axonal diameter was significantly greater in group A than in group B at 5 mm and 10 mm distal to the stump (
p
< 0.01 and
p
< 0.01, respectively). However, the SFI test and measured muscle wet-weight values showed no significant differences between the two groups.
Conclusions
Our study revealed that the Ochiai suture method for size-mismatched nerve transfer in rats increases the regenerative axon numbers and diameters. These findings suggest that the Ochiai suture method could be a valuable approach for achieving effective motor function restoration in cases of size-mismatched nerve transfer.
Objectives: To examine the efficacy and clinical and radiological outcomes of the use of a streamlined clavicle plate® (MEIRA, Aichi, Japan) for midshaft clavicular fractures.Methods: This was a ...retrospective cohort study of 155 patients with displaced midshaft clavicular fractures treated using a streamlined clavicle plate between 2015 and 2019 in 18 hospitals across Japan. A questionnaire regarding bone union and postoperative complications was used, and 136 cases were followed up for one year or until bone union. Plate fitting was evaluated retrospectively using surgical records, radiographic findings, and surgeon’s opinion.Results: During surgery, plate bending was needed in 19 cases (12.3%), poor fitting was observed in 8 cases (5.2%), and bone union was achieved in 133 cases (97.8%). Total implantation failure, including plate breakage and screw loosening, occurred in 10 cases (6.5%) from the intraoperative to postoperative period. Subjective complications were observed in 26 cases (16.8%): incongruity around the surgical scar or in the anterior chest in 23, and contracture of the shoulder in three. Plate removal was performed in 66 cases (48.5%) per patient’s request.Conclusion: The use of a streamlined clavicle plate is effective for midshaft fractures of the clavicle, and the success rates of bone union and implantation using this approach are comparable to those of other existing plates.
The novel coronavirus (COVID-19) that emerged in 2019 and spread globally in 2020 has resulted in the imposition of lockdowns or a state of emergency in many cities worldwide. In Japan, a "new ...lifestyle" is being advocated. We hypothesize that the new lifestyle has changed people's use of their upper limbs during the COVID-19 pandemic. Therefore, through this questionnaire study, we aimed to determine the factors associated with exacerbation of symptoms during the pandemic and to investigate the current status of patients who require hand surgery.
This study was a prospective multi-center questionnaire survey. This study was conducted in Japan from December 2020 to July 2021 at university and general hospitals in nine prefectures. A questionnaire was administered to patients who visited a hospital with symptoms of nerve entrapment syndrome, osteoarthritis, or tenosynovitis.
A total of 502 patients with a mean age of 63.8 years responded. The 240 patients who experienced exacerbation (exacerbated and markedly exacerbated) were compared with other patients (unchanged, improved, and markedly improved). An increase in the time spent on personal computers and smartphones was associated with exacerbation of hand symptoms. Patients who wanted to undergo surgery but were postponed due to COVID-19 accounted for 23.5% of the outpatients. The mean scores for pain, jitteriness, and anxious depression in these patients were significantly higher than those of patients who did not want surgery.
Our results suggest that an increase in the time spent on personal computers and smartphones is associated with exacerbation of hand symptoms during the COVID-19 pandemic. Patients who wanted to undergo surgery but were postponed by COVID-19 experienced greater pain, jitteriness, and anxious depression.
In eukaryotes, the cell has the ability to modulate the size of the nucleus depending on the surrounding environment, to enable nuclear functions such as DNA replication and transcription. From ...previous analyses of nuclear size scaling in various cell types and species, it has been found that eukaryotic cells have a conserved scaling rule, in which the nuclear size correlates with both cell size and genomic content. However, there are few studies that have focused on a certain cell type and systematically analyzed the size scaling properties in individual species (intra-species) and among species (inter-species), and thus, the difference in the scaling rules among cell types and species is not well understood. In the present study, we analyzed the size scaling relationship among three parameters, nuclear size, cell size, and genomic content, in our measured datasets of terminally differentiated erythrocytes of five Anura frogs and collected datasets of different species classes from published papers. In the datasets of isolated erythrocytes from individual frogs, we found a very weak correlation between the measured nuclear and cell cross-sectional areas. Within the erythrocytes of individual species, the correlation of the nuclear area with the cell area showed a very low hypoallometric relationship, in which the relative nuclear size decreased when the cell size increased. These scaling trends in intra-species erythrocytes are not comparable to the known general correlation in other cell types. When comparing parameters across species, the nuclear areas correlated with both cell areas and genomic contents among the five frogs and the collected datasets in each species class. However, the contribution of genomic content to nuclear size determination was smaller than that of the cell area in all species classes. In particular, the estimated degree of the contribution of genomic content was greater in the amphibian class than in other classes. Together with our imaging analysis of structural components in nuclear membranes, we hypothesized that the observed specific features in nuclear size scaling are achieved by the weak interaction of the chromatin with the nuclear membrane seen in frog erythrocytes.
The large-scale simulation of gasification using a highly resolved coke model is a powerful tool for predicting structural changes in metallurgical coke in a blast furnace. The objective of this ...study was to evaluate the accuracy of a numerical simulation using the results obtained from laboratory-scale gasification experiments. For the experiment, a cylindrical coke sample with a radius of 20 mm was gasified using CO2 gas at 1373 K in a coke gasification reaction furnace until the conversion reached 0.2. In addition, a numerical simulation of the coke model developed from X-ray computer tomography images of the coke sample before the reaction was conducted at 1373 K. Three low-resolution coke models were developed using the full-resolution coke model. The reaction rate and the coke structure after reaction were compared between the experiment and the numerical simulation. As a result, the prediction accuracies of reaction rate and structural change decreased with decreasing the image resolution as overall trend.
•The simulation of gasification for highly-resolved coke model was validated.•The numerical results were compared with the lab-scale experimental results.•The overall conversion of the simulation was in good agreement with the experiment.•A limit of numerical resolution was explored to correctly predict local porosity.
Abstract
Background
To reproduce anatomical reduction and appropriate implant placement/choices during osteosynthesis for elbow fractures, we developed a 3D preoperative planning system. To assess ...the utility of 3D digital preoperative planning for the osteosynthesis of distal humerus fractures, we evaluated the reproducibility of implant reduction shapes and placements in patients with distal humerus fractures.
Methods
Twelve patients with distal humerus fractures who underwent osteosynthesis using 3D preoperative planning were evaluated. Reduction shapes were evaluated by the angle between the diaphysis axis and a line connecting the vertices of the medial epicondyle and the lateral epicondyle (epicondyle angle), and the angle between the diaphysis axis and the articular surface (joint angle) in the coronal plane, and the distance between the anterior diaphysis and the anterior articular surface in the sagittal plane (anterior distance) based on 3D images of the distal humerus. In addition, the implant positions were evaluated by the positions of the proximal and posterior edge of the plate, and the angle of the plate to the epicondyle line. The reproducibility was evaluated by intra-class correlation coefficients of the parameters between pre- and postoperative images.
Results
The intra-class correlation coefficients were 0.545, 0.802, and 0.372 for the epicondyle angle, joint angle, and anterior distance, respectively. The differences in the measurements between the preoperative plan and postoperative reduction were 2.1 ± 2.1 degrees, 2.3 ± 1.8 degrees, and 2.8 ± 2.0 mm, for the epicondyle angle, joint angle, and anterior distance, respectively. The intra-class correlation coefficients were 0.983, 0.661, and 0.653 for the proximal and posterior plate positions, and the angle to the epicondyle, respectively. The differences in the measurements between the preoperative plan and postoperative reduction were 3.3 ± 2.1 mm, 2.7 ± 1.7 mm and 9.7 ± 9.8 degrees, for the plate positions of proximal and posterior edge, and the angle of the plate to the epicondyle line, respectively. There were significant correlations for the epicondyle angle, joint angle, and plate positions.
Conclusions
3D preoperative planning for osteosynthesis of distal humerus fracture was reproducible for the reduction shape of the coronal view and the plate positions. It may be helpful for acquiring practical images of osteosynthesis in distal humerus fractures.
Level of evidence
Level III, a case–control study.
We compared cerebrospinal fluid (CSF) leak conspicuity and image quality as visualized using 3D versus 2D magnetic resonance (MR) myelography in patients with spinal CSF leaks.
Eighteen patients ...underwent spinal MR imaging at 3 Tesla. Three board-certified radiologists independently evaluated CSF leak conspicuity and image quality on a 4-point scale; the latter assessed by scoring fat suppression, venous visualization, and severity of CSF flow artifacts. Additionally, the evaluators ranked the overall performances of 2D versus 3D MR myelography upon completing side-by-side comparisons of CSF leak conspicuity. Inter-reader agreement was determined using the Gwet’s AC1.
The quality of 3D MR myelography images was significantly better than that of 2D MR myelography with respect to CSF leak conspicuity (mean scores: 3.3 vs. 1.9, p < 0.0001) and severity of CSF flow artifacts on the axial view (mean scores: 1.0 vs. 2.5, p = 0.0001). Inter-reader agreement was moderate to almost perfect for 2D MR myelography (AC1 = 0.55–1.00), and almost perfect for 3D MR myelography (AC1 = 0.85–1.00). Moreover, 3D MR myelography was judged to be superior to 2D acquisition in 78 %, 83 %, and 83 % of the samples per readers 1, 2 and 3, respectively; the inter-reader agreement was almost perfect (AC1: reader 1 vs. 2; 0.98, reader 2 vs. 3; 0.96, reader 3 vs. 1; 0.98).
CSF leaks are more conspicuous when using 3D MR myelography than when using its 2D counterpart; therefore, the former is more reliable for identifying such leaks.
Few studies have compared the unaffected and affected sides in the same carpal tunnel syndrome (CTS) patients using ultrasonography and electrophysiological tests. We focused on unilateral idiopathic ...CTS patients to investigate whether clinical test results differ between the unaffected and affected sides. The bilateral wrist joints of 61 unilateral idiopathic CTS patients were evaluated. The median nerve cross-sectional area of ultrasound image, and latencies of the compound muscle action potential (CMAP) and sensory nerve action potential (SNAP) were measured. The values obtained were compared between the affected and unaffected sides. The diagnostic accuracies of each parameter were assessed, and cut-off values were defined. Significant differences were observed in all parameters between the affected and unaffected sides (p < 0.01). Area under the curve (AUC) values were 0.74, 0.88, and 0.73 for the cross-sectional area, CMAP distal latency, and SNAP distal latency, respectively. Cut-off values were 11.9 mm2, 5.1 ms, and 3.1 ms for the cross-sectional area, CMAP distal latency, and SNAP distal latency, respectively. The most reliable parameter that reflected clinical symptoms was the distal latency of CMAP. Cut-off values for each parameter are considered to be an index for the onset of the clinical symptoms of CTS.
To assess the usefulness of contrast-enhanced 3D STIR FLAIR imaging for evaluation of pituitary adenomas.
Patients with pituitary adenomas underwent MR examinations including contrast-enhanced 3D ...STIR FLAIR and 2D T1-weighted (T1W) imaging. We subjectively compared the two techniques in terms of 10 categories. In addition, images were rated by side-by-side comparisons into three outcomes: 3D STIR FLAIR imaging superior, equal, or 2D T1W imaging superior. Additionally, the added value of 3D STIR FLAIR imaging for adenoma detection over conventional MR imaging was assessed.
Twenty-one patients were included in this study. 3D STIR FLAIR imaging offered significantly better images than 2D T1W imaging in terms of three categories, including overall visualization of the cranial nerves in the cavernous sinus (mean 4.0 vs. 2.8, p < 0.0001), visualization of the optic nerves and chiasm (mean 4.0 vs. 2.6, p < 0.0001), and severity of susceptibility artifacts (mean 0.0 vs. 0.4, p = 0.004). In the side-by-side comparison, 3D STIR FLAIR imaging was judged to be significantly superior to 2D T1W imaging for overall lesion conspicuity (62% vs. 19%, p = 0.049) and border between the adenoma and the pituitary gland (67% vs. 19%, p = 0.031). The addition of 3D STIR FLAIR imaging significantly improved the adenoma detection of conventional MR imaging.
3D STIR FLAIR imaging improved overall lesion conspicuity compared to 2D T1W imaging. We suggest that 3D STIR FLAIR imaging is recommended as a supplemental technique when pituitary adenomas are invisible or equivocal on conventional imaging.
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