Torsional Values Research Articles

A new method for assessing tibial torsion using computerized tomography in a pediatric population.

Tibial torsion disorders may lead to abnormal gait, frequently leading to a consultation with a pediatric orthopedic surgeon. The present study evaluated an alternative method for assessing tibial torsion on computerized tomography (CT) images that considers the tibial distal axis to be equivalent to the geometric axis of the tibiotalar joint. One hundred CT scans were reviewed retrospectively, and four measurements were taken: proximal transtibial angle (PTTA), posterior margin tibial plateau angle (PMTPA), intermalleolar angle (IMA), and talar angle (TA). The tibial torsion angle was then calculated using these different angles. The patient cohort comprised 38 girls and 62 boys, with a mean age of 12 ± 4.4 years. Median PTTA and PMTPA were -8.4° ± 14.7° and -8.8° ± 14.2°, respectively, with no statistically significant difference. Mean IMA and TA were 23° ± 16.2° and 17.2° ± 16.9°, respectively, with a statistically significant difference. Mean total measurement time per patient was 6'44", with means of 2'24" for PTTA, 36" for PMTPA, 2'14" for IMA, and 1'12" for TA. Tibial torsion values may differ significantly depending on the axis chosen to define tibial orientation. At the level of the proximal tibia, the choice of PTTA or PMTPA had little influence on the calculation of the tibial torsion angle. There was a significant difference of 5.8° when measuring the distal tibia. Measuring the PMTPA and TA is probably more suited for use in clinical practice because their tracing is simple and faster.

Coupled internal rotations and 14N quadrupole hyperfine structure of 2,4-dimethylpyrrole investigated by microwave spectroscopy and quantum chemistry.

The microwave spectrum of 2,4-dimethylpyrrole was investigated using a Fourier-transform microwave spectrometer in a supersonic expansion. Torsional splittings arising from two inequivalent methyl internal rotors in combination with hyperfine splittings due to the nuclear quadrupole coupling of the 14N nucleus were observed. The experiments were accompanied by quantum chemical calculations. A total of 1561 rotational lines were assigned and fitted in global fits using the programs XIAM and BELGI-Cs-2Tops-hyperfine, both achieved the measurement accuracy of 4kHz. Local separate fits were also performed to verify the correctness of the assignment. Accurate experimental molecular and internal rotation parameters could be deduced and compared to the calculated ones. The barrier to internal rotation of the 2-methyl rotor was determined to be 277.830(26) cm-1, essentially the same as the value of about 280cm-1 found for 2-methylpyrrole but lower than the value of 317cm-1 found for 2,5-dimethylpyrrole. The torsional barrier value of the 4-methyl rotor is 262.210(27) cm-1, slightly higher than the value of 246cm-1 found for 3-methylpyrrole. Benchmarking the rotational constants for 2,4- and 2,5-dimethylpyrrole revealed that the MP2/6-31G(d,p) level could be helpful to guide the assignment of microwave spectra of pyrrole derivatives.

Topology optimization based on combined mechanical analysis and variable density method for casting structure

In this study, a topology optimization method based on combined mechanical analysis and variable density is presented for a large-scale casting structure with complex thin-walled structures. First, the mechanical analysis model of the frame is established, the first-order bending and torsional modes and stiffness values of the all-cast aluminum frame are obtained, and the basic mechanical parameters such as bending/torsional mode and stiffness constraints needed for topology optimization are defined. Using the variable density method, unneeded material that can be removed from the casting structure is identified. According to the design requirements, the optimization objective function and constraint conditions are established, and the variable density method is used to solve the problem. Analysis of the mechanical results before and after topology optimization reveals that the modes and stiffness values are larger than the target values, and the mass of the frame is reduced by 10.2 kg (i.e. 13.9%) compared with the original design. The application of the combined mechanical analysis and variable density method to a casting structure can effectively achieve lightweight design.

The experimental and numerical investigation of fracture behaviour in PMMA notched specimens under biaxial loading conditions – Tension with torsion

This paper presents the results of experimental fracture test of flat PMMA specimens under biaxial loading condition tension with torsion (proportional). The specimens were made in two thicknesses: 5 and 15 mm and were weakened with V-type edge notches with different root radii: 0.5; 2 and 10 mm. Thanks to the ARAMIS 3D 4 M non-contact vision system, measurement of the elongation and twist angle were recorded. During experimental part all of the deformation processes were observed using PHANTOM cameras. Obtained records made it possible to precisely indicate the moment of crack initiation (tensile force and torsional moment values). Using the microscopic observations the location of crack initiations were determined. Results obtained for biaxial loading were compared with those obtained for uniaxial tension and torsion. Based on experimental data the numerical calculation with FEM were carried out. The principal stress and plastic strain distribution under critical load, were obtained. The points of occurrence of stress maxima and plastic strain were indicated, which were taken as potential crack initiation sites. On the basis of the stress and plastic strain values measured at the critical points, a stress–strain fracture criterion was formulated, which was then positively verified. Additionally, new form of stress–strain fracture criterion was proposed. The bilinear form of the fracture criterion can be successfully used to predict fracture in PMMA flat specimens, regardless of the notch root radius, type of load or element thickness.

Failure analysis of bolted steel plate connections with three-dimensional flexibilities

Steel plates are widely used in construction to connect different structural elements using welding or bolts. The fracture in these plates may lead to catastrophic consequences such as structural collapse. The paper investigates steel plates' deformation capacity and fracture behavior in bolted connections in three-dimensional (3D) flexibility. The peridynamic method is utilized to model the excessive deformation and fracture of steel plates in bolted connections when they are influenced by shear, moment, and torsion. The mesh-free nature of peridynamics enables modeling the extreme deformation and fracture in ductile materials such as steel. We validate the 3D peridynamic model by comparing its fracture and deformation results with experimental measurements and observations in several loading and boundary conditions. The paper highlights the following novelties: (1) a new and highly efficient 3D peridynamic model is proposed to model fractures in steel plates when exposed to combined actions of shear, moment, and torsion simultaneously; (2) the proposed 3D peridynamic model overcomes the difficulties faced by the mesh-based methods in modeling excessive deformation in ductile materials such as steel; (3) the study also reveals a shift in the fracture behavior of steel plates from ductile to brittle when exposed to high values of moment and torsion. This shift in fracture behavior has not been thoroughly addressed, impacting the integrity of steel structures and the warning stage for yielding. Overall, utilizing the 3D peridynamic model as a modeling and simulation tool can help engineers and researchers examine the behavior of steel plates under various loading conditions, thus allowing for optimization of the design of steel plates used widely in steel construction.

Quantum Field Theory of Neutrino Mixing in Spacetimes with Torsion

In the framework of quantum field theory, we analyze the neutrino oscillations in the presence of a torsion background. We consider the Einstein–Cartan theory and we study the cases of constant torsion and of linearly time-dependent torsion. We derive new neutrino oscillation formulae which depend on the spin orientation. Indeed, the energy splitting induced by the torsion influences oscillation amplitudes and frequencies. This effect is maximal for values of torsion of the same order of the neutrino masses and for very low momenta, and disappears for large values of torsion. Moreover, neutrino oscillation is inhibited for intensities of torsion term much larger than neutrino masses and momentum. The modifications induced by torsion on the CP-asymmetry are also presented. Future experiments, such as PTOLEMY, which have as a goal the analysis of the cosmological background of neutrino (which have very low momenta), can provide insights into the effect shown here.

Three-dimensional elastic properties of open-cell porous structures: Analytic and finite element modelling

The current paper introduces a three-dimensional micromechanical model of open-cell cellular solid materials and presents the homogenization of the model to an orthotropic continuum. An orthotropic microstructural beam model was created and tested under pure stretch and pure angular distortion to identify the dominant deformation modes by mapping the contributions of normal-, bending- and torsional stiffness to the total strain energy. In the case of unidirectional tension, the deformation mode was dependent primarily on the proportion of normal- and bending stiffnesses, except for the cases with similarly small bending- and torsional stiffness values, where the contribution of torsion was significant. In the case of the pure angular distortion, the key deformation mode was defined by the ratio of bending- and torsional stiffness values, except for the case of large normal- and torsional stiffness values, which resulted in normal-deformation-driven behaviour.The homogenization of the micromodel was conducted by creating an equivalent spring model, by means of which the equivalent elastic modulus values for the main directions of orthotropy have been derived as functions of the geometric and elastic properties of the beams. With the aid of the equivalent spring models, the relative density dependence of Young’s modulus and shear modulus have been examined. The typical second-degree relationship was found to become inaccurate in the range of lower porosity. In the case of increasing relative density values, the exponent of the elastic modulus function decreased while the exponent of the shear modulus increased.

Evaluation the relationship between myocardial fibrosis and left ventricular torsion measured by cardiac magnetic resonance feature-tracking in hypertrophic cardiomyopathy patients with preserved ejection fraction.

The relationship between left ventricular (LV) torsion and myocardial fibrosis (MF) in hypertrophic cardiomyopathy (HCM) patients with preserved ejection fraction was still not well understood. New developments in cardiac magnetic resonance (CMR) enable a much fuller assessment of cardiac characteristics. This study sought to assess the impact of HCM on myocardial function as assessed by LV torsion and its relationship with MF. HCM (n = 79) and healthy controls (n = 40) underwent CMR. According to whether there was late gadolinium enhancement (LGE), patients were divided into LGE+ group and LGE- group. LV torsion and torsion rate were measured by CMR feature-tracking (CMR-FT). MF was quantitatively evaluated through LGE imaging. LGE was present in 44 patients (56%). Compared with healthy controls, torsion increased in the LGE- group (P < 0.001). Compared with LGE+ group, torsion was higher in the LGE- group (P < 0.001). There was no significant difference in torsion between LGE+ group and healthy controls. Correlation analysis showed that torsion was correlated with LGE% (r= -0.443) and LGE mass (r= -0.435) respectively. On multivariable logistic regression analysis, LV torsion was the only feature that was independently associated with the presence of LGE (OR 0.130; 95% CI 0.040 to 0.420, P = 0.01). The best torsion value associated with MF was 1.91 (sensitivity 60.0%, specificity 77.3%, AUC = 0.733). In HCM patients with preserved ejection fraction, CMR-FT derivedLV torsion analysis holds promise for myocardial fibrosis detection.

Low-profile prosthetic foot stiffness category and size, and shoes affect axial and torsional stiffness and hysteresis.

Passive-elastic prosthetic feet are manufactured with numerical stiffness categories and prescribed based on the user's body mass and activity level, but mechanical properties, such as stiffness values and hysteresis are not typically reported. Since the mechanical properties of passive-elastic prosthetic feet and footwear can affect walking biomechanics of people with transtibial or transfemoral amputation, characterizing these properties can provide objective metrics for comparison and aid prosthetic foot prescription and design. We characterized axial and torsional stiffness values, and hysteresis of 33 categories and sizes of a commercially available passive-elastic prosthetic foot model [Össur low-profile (LP) Vari-flex] with and without a shoe. We assumed a greater numerical stiffness category would result in greater axial and torsional stiffness values but would not affect hysteresis. We hypothesized that a greater prosthetic foot length would not affect axial stiffness values or hysteresis but would result in greater torsional stiffness values. We also hypothesized that including a shoe would result in decreased axial and torsional stiffness values and greater hysteresis. Prosthetic stiffness was better described by curvilinear than linear equations such that stiffness values increased with greater loads. In general, a greater numerical stiffness category resulted in increased heel, midfoot, and forefoot axial stiffness values, increased plantarflexion and dorsiflexion torsional stiffness values, and decreased heel, midfoot, and forefoot hysteresis. Moreover, for a given category, a longer prosthetic foot size resulted in decreased heel, midfoot, and forefoot axial stiffness values, increased plantarflexion and dorsiflexion torsional stiffness values, and decreased heel and midfoot hysteresis. In addition, adding a shoe to the prosthetic foot resulted in decreased heel and midfoot axial stiffness values, decreased plantarflexion torsional stiffness values, and increased heel, midfoot, and forefoot hysteresis. Our results suggest that manufacturers should adjust the design of each category to ensure the mechanical properties are consistent across different sizes and highlight the need for prosthetists and researchers to consider the effects of shoes in combination with prostheses. Our results can be used to objectively compare the LP Vari-flex prosthetic foot to other prosthetic feet to inform their prescription, design, and use for people with a transtibial or transfemoral amputation.

Torsional vibration behavior of a restrained non-circular nanowire in an elastic matrix

This study introduces an approach to analyze torsional vibration in non-circular nanowires within magnetic fields, considering various boundary conditions on an elastic foundation. Analytical formulas for natural angular frequencies are obtained using nonlocal strain gradient theory. The analysis covers three non-circular cross-sections, incorporating the warping effect. Elastic springs at the wire ends simulate support conditions, restricting rotation around the wire’s axis. The torsion function around the axis is represented by a Fourier series, discretized at the spring points and linked using the Stokes’ transform alongside the boundary values. This leads to an eigenvalue problem that includes higher-order material size parameters (strain gradient, nonlocal), spring parameters, and the warping function. The study’s novelty lies in effectively solving torsional vibration for non-circular sections, addressing warping function, elastic medium, and size effects under both deformable and non-deformable boundary conditions. The presented solution is capable of determining vibration frequencies for both rigid and deformable boundary conditions. This is accomplished by specifying the torsional spring stiffness values, thereby obviating the necessity for additional recalculations. In order to verify the obtained results and compare them with the existing literature, nanowires with free and clamped boundary conditions are solved numerically by changing the spring parameters in the eigenvalue problem. In the formulation of natural angular frequency; length scale parameters, warping, magnetic field, elastic medium effects are included. In addition, since the support conditions are modeled with elastic springs, the resulting formulas are quite general and can be used to solve different types of torsional vibration problems.

Seismic pounding of adjacent buildings considering torsional effects

This study aims to evaluate pounding effects in fixed-base models by considering torsional irregularity. For this purpose, 8 different adjacent building combinations were created by using 3-dimensional 5- and 9-story building models. In adjacent building models, the most critical situation was determined by evaluating the gap distance, different sequences of the same building models and regular or irregular plan view and if the structures are irregular, their eccentricity cases relative to each other. Nonlinear behavior of structural elements was taken into account for examine the change in the seismic behavior of structural elements due to pounding and torsion effects. The nonlinear time history analysis of the adjacent models was performed for 11 pairs of spectrum compatible ground motion recordings in the SAP2000 program. The results of 176 different analyzes show that the displacement demand, interstory drift ratio, damage ratio and torsional irregularity coefficient values tend to increase in general with the combined effects of pounding and torsion. The absolute maximum and most critical values of the relevant parameters were calculated in irregular structures with pounding where the eccentricity of buildings is in the same direction and same side. In addition, the large standard deviation of the result values according to the ground motion records indicates that care should be taken in choosing the number of ground motion records.

Suspension Bridges Versus Cable-Stretched Bridges: A Comparison of Structural Behaviour and Performance

A suspension bridge and a cable-stayed bridge are compared under various loads and environmental conditions in this study. Under live, dead, and seismic loads, the research investigates axial forces, displacements, bending moments, and shear forces using advanced analytical methods and software such as CsiBridge, SAP2000, and Staad Pro. Steel plays a key role in the construction of suspension bridges and cable-stayed bridges, as this study thoroughly compares both types of bridges. Csi Bridge software is utilized in this study to investigate the axial force, displacement, bending moment, and shear strength of these bridges under various loading conditions. Cable-stayed bridges are recognized for their aesthetic benefits and structural efficiency for medium-to-long spans, and suspension bridges for their high tensile strength and durable design. The two bridge types exhibit different shear forces, displacements, and torsional values, underscoring their unique engineering designs.

Healthy Adult Left and Right Ventricular Torsion and Torsion Rates With MR-Feature Tracking.

The clinical value of myocardial torsion quantification in prognostic assessment and risk stratification of various cardiovascular diseases is gradually being recognized. However, normal values of left and right ventricular (LV and RV) torsion and torsion rates (TRs) have not been fully determined, and their correlation with age and gender has not been well studied. To establish normal ranges of biventricular torsion, peak systolic and diastolic TRs using magnetic resonance feature tracking (MR-FT) technique based on a large sample of healthy adults, and further investigate their relationship with age and gender. Retrospective. 566 Healthy adults (312 males, aged 43 ± 10 years; 254 females, aged 43 ± 11 years). 1.5T/gradient echo. Biventricular torsion, peak systolic, and diastolic TRs. Shapiro-Wilk test, Student's t-test, Mann-Whitney-U test, linear regression, intraclass correlation coefficient, Bland-Altman analysis. Differences were regarded as statistically significant at P < 0.05. Women demonstrated greater magnitudes of left ventricle (LV) torsion (1.23 ± 0.44 vs. 1.00 ± 0.42°/cm), peak systolic TR (9.69 ± 3.70 vs. 8.27 ± 3.73°/cm*sec), peak diastolic TR (-7.78 ± 2.82 vs. -6.06 ± 2.44°/cm*sec), and RV torsion (2.20 ± 1.23 vs. 1.65 ± 1.11°/cm*sec), peak systolic TR (16.07 ± 8.18 vs. 12.62 ± 7.08°/cm*sec), peak diastolic TR (-15.39 ± 6.53 vs. -11.70 ± 6.03°/cm*sec). For both genders, the magnitudes of LV and RV torsion, peak systolic, and diastolic TRs increased linearly with age. All the measurements of biventricular torsion, peak systolic and diastolic TRs achieved good to excellent intraobserver and interobserver reproducibility, with all intraclass correlation coefficients >0.70. The present study systematically provided age- and sex-stratified reference values for LV and RV torsion and TRs using MR-FT technique. Women and aging are associated with greater magnitudes of biventricular torsion, peak systolic, and diastolic TRs. 3 TECHNICAL EFFICACY: Stage 2.

The assessment of structural behaviours of steel framing system – affordable house system design

Purpose Nowadays, residential buildings have become increasingly important due to the growing communities. The purpose of this study is to investigate the behavior of a steel structural framing system that incorporates lightweight load-bearing walls and slabs, and to compare the weight of materials used in cold-formed and hot-finished steel structural systems for affordable housing. Design/methodology/approach Four types of models consisting of 243 members were simulated. Model 1 is a cold-formed steel structural framing system, while Model 2 is a hot-finished steel structural framing system. Both Models 1 and 2 use lightweight wall panels and lightweight composite slabs. Models 3 and 4 are made with brick walls and precast reinforced concrete systems, respectively. These structures use different wall and slab materials, namely, brick walls and precast reinforced concrete. The analysis includes bending behavior, buckling resistance, shear resistance and torsional rotation analysis. Findings This study found that using thinner steel sections can increase the deflection value. Meanwhile, increasing member length and the ratio of slenderness will decrease buckling resistance. As the applied load increases, buckling deformation also increases. Furthermore, decreasing shear area causes a reduction in shear resistance. Thicker sections and the use of lightweight materials can decrease the torsional rotation value. Originality/value The weight comparison of the steel structures shows that Model 1, which is a cold-formed steel structure with lightweight wall panels and lightweight composite slabs, is the most suitable model due to its lightweight and affordability for housing. This model can also be used as a reference for the optimal design of modular structural framing using cold-formed steel materials in the field of civil engineering and as a promotional tool.

Effect of Lower Extremity Torsion on Clinical Outcomes After Medial Patellofemoral Ligament Reconstruction and Tibial Tubercle Transfer for Recurrent Patellofemoral Instability

Background: Increased femoral torsion (FT) or tibial torsion (TT) has been suggested to be a potential risk factor for recurrent patellofemoral instability. However, the influence of increased FT or TT on the postoperative clinical outcomes of recurrent patellofemoral instability has rarely been investigated. Purpose: To assess the effect of increased FT or TT on postoperative results in patients with recurrent patellofemoral instability after combined medial patellofemoral ligament reconstruction (MPFLR) and tibial tubercle transfer, along with the influence of other risk factors. Study Design: Cohort study; Level of evidence, 3. Methods: Out of 91 patients, the study’s analyses included 86 patients with recurrent patellofemoral instability who were treated with MPFLR and tibial tubercle transfer and enrolled between April 2020 and January 2021. FT and TT were assessed using preoperative computed tomography images. According to the torsion value of FT or TT, patients were categorized into 3 groups for each of FT and TT: group A (<20°), group B (20°-30°), and group C (>30°). Patellar height, femoral trochlear dysplasia, and the tibial tuberosity–trochlear groove (TT-TG) distance were also assessed. Patient-reported outcome scores (Tegner, Kujala, International Knee Documentation Committee [IKDC], Lysholm, and Knee injury and Osteoarthritis Outcome Score [KOOS]) were evaluated pre- and postoperatively. Clinical failure of MPFLR was recorded. Subgroup analysis was conducted to evaluate the effect of increased FT or TT on the postoperative outcomes. Results: A total of 86 patients were enrolled with a median follow-up time of 25 months. At the final follow-up, all functional scores improved significantly. Patella alta, high-grade trochlear dysplasia, and increased TT-TG distance did not have any significant effect on the postoperative functional scores. Regarding FT, subgroup analysis indicated that all functional scores of group C were lower than those of groups A and B except the KOOS knee-related Quality of Life score. For TT, group C had lower scores than group A for all functional outcomes except Tegner and KOOS Quality of Life and lower scores than group B for Kujala, IKDC, KOOS (Symptoms and Sport and Recreation subscales), Tegner, and Lysholm scores. The comparison between group A and group B, whether for FT or TT, revealed no significant differences. Conclusion: For patients with recurrent patellofemoral instability, increased lower extremity torsion (FT or TT >30°) was associated with inferior postoperative clinical outcomes after combined MPFLR and tibial tubercle transfer.

CORROBORATING TESTICULAR WORK UP FOR ISCHEMIAAND SUSPECTED TORSION [TWIST] SCORE IN THE EVALUATION OF TESTICULAR TORSION IN PATIENTS PRESENTING WITH ACUTE SCROTUM: A STUDY FROM A TERTIARY CARE CENTRE IN CENTRAL INDIA

Objective: To study the testicular workup for ischemia and suspected torsion (TWIST) score for evaluation of patients presenting with acute scrotum. Method:An observational study was done amongst the patients presenting with acute scrotum of the emergency department of a tertiary care hospital. The scoring system , as described by Barbosa, et al, consisted of testicular swelling(2), hard testicle(2), absent cremastric reex(1), nausea/vomiting(1), high riding testis(1). Along the entire duration of the study the same standard of resources were used in terms of radiological investigations and the surgery performed. Results: In the testicular torsion group, the mean TWIST score was 5.4 ranging from 4 to 7 while in the non torsion group it was 2.81 ranging from 2 to 6. In the testicular torsion group the no. of patients belonging to low, intermediate and high risk was 0, 2 and 8, respectively, while the number of patients without testicular torsion was 5, 5 and 1 in low, intermediate and high risk groups respectively. Conclusion: The testicular workup for ischemia and suspected torsion (TWIST) score can be used a tool for evaluation of patients presenting with acute scrotum. The score has a high positive predictive value for testicular torsion

Experimental and simulative investigation of welding sequences on thermally induced distortions in wire arc additive manufacturing

PurposeThe purpose of this paper is to demonstrate the impact of the welding sequence on the substrate plate distortion during the wire and arc additive manufacturing (WAAM) process. This paper also aims to show the capability of finite element simulations in the prediction of those thermally induced distortions.Design/methodology/approachAn experiment was conducted in which solid aluminum blocks were manufactured using two different welding sequences. The distortion of the substrates was measured at predefined positions and converted into bending and torsion values. Subsequently, a weakly coupled thermo-mechanical finite element model was created using the Abaqus simulation software. The model was calibrated and validated with data gathered from the experiments.FindingsThe results of this paper showed that the welding sequence of a part significantly affects the formation of thermally induced distortions of the final part. The calibrated simulation model was able to capture the different distortion behavior attributed to the welding sequences.Originality/valueWithin this work, a simulation model was developed capable of predicting the distortion of WAAM parts in advance. The findings of this paper can be used to improve the design of WAAM welding sequences while avoiding high experimental efforts.

Determination of Standard Values for Knee Version in a Healthy Population

Background: Different measures are used to describe relevant anatomic variations that can result in patellofemoral instability and disorders. Knee version, the relative rotational alignment between the femur and tibia in the axial plane at the level of the knee, may have a decisive effect on the kinematics of the patellofemoral joint. However, data regarding the values of knee version are currently lacking. Purpose: This study aimed to determine standard values for knee version in a healthy population. Study Design: Cross-sectional study; Level of evidence, 3. Methods: A total of 100 healthy volunteers (50 male and 50 female) without patellofemoral disorders or lower extremity malalignment were included in this study and underwent knee magnetic resonance imaging. The torsion values of the femur and tibia were independently measured using the Waidelich and Strecker method. Knee version, defined as static rotation of the tibia with respect to the femur in full extension, was determined by measuring the angle between the tangent lines to the dorsal femoral condyle (DFC) and the dorsal tibial head (DTH; defined by the posterior point of the proximal tibial plateau). Supplementary measurements were obtained as follows: (1) femoral epicondylar line (FEL), (2) tibial ellipse center line (TECL), (3) tibial tuberosity–trochlear groove (TT-TG) distance, and (4) tibial tuberosity–posterior cruciate ligament (TT-PCL) distance. Results: In 200 analyzed legs of 100 volunteers (mean age, 26.5 ± 5.8 years [range, 18 to 40 years]), we identified a mean internal femoral torsion of −23.8°± 9.7° (range, −46.2° to 1.6°), external tibial torsion of 33.2°± 7.4° (range, 16.4° to 50.3°), and external knee version (DFC to DTH) of 1.3°± 3.9° (range, −8.7° to 11.7°). Other measurements were as follows: FEL to TECL, −0.9°± 4.9° (range, −16.8° to 12.1°); FEL to DTH, −3.6°± 4.0° (range, −12.6° to 6.8°); and DFC to TECL, 4.0°± 4.9° (range, −12.7° to 14.7°). The mean TT-TG distance was 13.4 ± 3.7 mm (range, 5.3-23.5 mm), and the mean TT-PCL distance was 11.5 ± 3.5 mm (range, 6.0-20.9 mm). Female participants had significantly greater external knee version than male participants. Conclusion: Coronal- and sagittal-plane alignments of the knee have a well-known effect on the biomechanics of this joint. Additional information about the axial plane may result in new decision-making algorithms for managing knee disorders. This study is the first to report standard values of knee version in a healthy population. As a subsequent step building on this work, we advocate for the measurement of knee version in patients with patellofemoral disorders, as this parameter may assist with new treatment guidelines in the future.

Predictive factors of bowel resection for midgut volvulus based on an analysis of bi-center experiences in southern Japan.

Midgut volvulus is an urgent disease often occurring in neonates. This study clarified the clinical features of midgut volvulus and evaluated predictors to avoid bowel resection. This bi-center retrospective study enrolled 48 patients who underwent surgery for intestinal malrotation between 2010 and 2022. Patients' background characteristics and preoperative imaging findings were reviewed. Midgut volvulus was recognized in 32 patients (66.7%), and 6 (12.5%) underwent bowel resection. Based on a receiver operating curve analysis of bowel resection, the cut-off value of the body weight at birth and at operation were 1984g [area under the curve (AUC) 0.75, 95% confidence interval (CI) 0.52-0.99] and 2418g (AUC 0.70, 95% CI 0.46-0.94), respectively. The cut-off value of intestinal torsion was 540° (AUC 0.76, 95% CI 0.57-0.95), and that of the time from the onset to the diagnosis was 12h (AUC 0.85, 95% CI 0.72-0.98). For midgut volvulus with an intestinal torsion > 540°, the most sensitive preoperative imaging test was ultrasonography (75%) Patients with bloody stool tended to undergo bowel resection. Patients with a low body weight and bloody stool should be confirmed to have whirlpool sign by ultrasonography and scheduled for surgery as soon as possible.

Innovative Solution of Torsional Vibration Reduction by Application of Pneumatic Tuner in Shipping Piston Devices

The industries of shipping, shipbuilding and port operations are among those in which mechanical drives with piston machines are widely used. The wide use of piston machines is the result of many years of experience and many years of development and modernization of piston machines. Usually, they operate as mechanical drives with constant operating speeds, with the exception of drives with combustion engines, which operate in a wider range of operating speeds. The limiting condition of innovation of mechanical drives with piston machines, resulting from the nature of the piston machine operation, is the torsional oscillation. The effort to decrease an energy demand of mechanical drives requires the application of non-traditional working modes, which can be considered as a deactivation of the cylinders of piston machine or an expansion of the working speed range. One of the possibilities of eliminating these limiting factors is an application of a pneumatic tuner in mechanical drives, which, in contrast to traditional solutions, has a wide range of torsional stiffness that can be smoothly changed. During experimental measurements in the resonance area, at the operating speed of 700 rpm after torsional stiffness change, a torsional vibration value of 15 Nm decreased to 5 Nm.