Double Plate Research Articles

Vibration localization and reduction of double-plate structures

A thin plate-type resonator is attached to a host-stepped plate to achieve vibration localization and reduction in initial low-order global vibration modes. A semi-analytical method is proposed to analyze the free and forced vibrations of the double-plate structure, considering the geometric configuration's heterogeneity and discontinuity. The double plate structure is divided into several sub-plates for individual modeling, with admissible functions constructed for the displacements of each subdomain. These subdomains are then combined into a unified whole through displacement compatibility conditions. The no-orthogonality between global vibration and localized modes is determined using analytic mode functions obtained by the Ritz method with special admissible functions, which is crucial for suppressing the multiple resonance peaks of global vibration using the integrated plate-type resonator. An intriguing finding is that at the frequency veering point of global vibration modes and localized modes, the non-orthogonality can lead to two coupled global-localized modes that are similar to the initial localized mode, and the vibration of initial global modes can be mainly concentrated in the resonator region outside the plate during free vibration. For force vibration of the double plate, the initial resonance peak splits from one into two smaller resonance peaks due to the two coupled global-localized modes. Furthermore, the coupled global-localized mode allows for a substantial reduction in the host plate vibration while making a negligible impact on the total mass and global vibration frequency. This study presents a promising approach for reducing multimodal vibrations in lightweight structures.

Heat and mass transmission through the nanofluids flow subject to exponential heat source/sink and thermal convective condition across Riga plates

The analysis of the squeezing nanofluid flow across bounded domains received great attention from researchers and engineers due to its tremendous application in automobiles, energy exchangers, and aerodynamics. In the current analysis, we are using double Riga plates parallel to each other, in order to induce the squeezing nanofluids flow with the significances of chemical reaction, thermal radiation, and heat source/sink. The nanoliquid has been prepared by the dispersion of Copper (Cu) nanoparticles (NPs) in kerosene oil (C12H26C15H32) and water (H2O). The nanofluid flow has been modeled in form of nonlinear partial differential equations, which are further convert into the dimensionless form of ordinary differential equations. The obtained set of non-dimensional equations is numerically resolved by using the Matlab built-in package bvp4c. The results are compared to another numerical technique for accuracy purposes. The detailed results are presented in Figures. It has been detected that the energy field of nanofluid is enriched with the effect of heat source/sink component. Moreover, the velocity curve magnifies with the variation of the squeezing parameter of Riga plates, whereas declines with the accumulation of Cu-NPs in both types of base fluid (C12H26C15H32 and H2O).

Determination of In Vitro Biocontrol Efficacy of Trichoderma Harzianum Against Some Wheat Pathogen Fusarium Species

Recently, phytopathogenic problems have been increasing day by day in cereal production and have adverse effects on its production. One of the most common methods applied to control phytopathogens is the use of synthetic chemicals. The impacts of pesticides on the environment and food safety have made their use controversial. Therefore, developing and applying methods that can replace agricultural chemicals is an issue that needs to be emphasized. In this sense, biocontrol can be an alternative approach against agrochemicals in terms of sustainable agriculture. In the present study, it was aimed to examine the biocontrol efficiency of Trichoderma harzianum against Fusarium graminearum, Fusarium culmorum and Fusarium avenaceum, causing product losses in wheat by dual culture tests and double plate assays. Results showed that T. harzianum had remarkable inhibition of mycelial growth of all Fusarium species in dual culture assays. Moreover, no statistically crucial differences were found in the double plate tests.

Biomechanical analysis of fixation methods for bone flap repositioning after lateral orbitotomy approach: A finite element analysis

ObjectiveIn ophthalmic surgery, different materials and fixation methods are employed for bone flap repositioning after lateral orbitotomy approach (LOA), yet there is no unified standard. This study aims to investigate the impact of different fixation strategies on orbital stability through Finite Element Analysis (FEA) simulations of the biomechanical environment for orbital rim fixation in LOA. MethodsA Finite Element Model (FEM) was established and validated to simulate the mechanical responses under various loads in conventional lateral orbitotomy approach (CLOA) and deep lateral orbital decompression (DLOD) using single titanium plate, double titanium plates, and double absorbable plates fixation methods. The simulations were then validated against clinical cases. ResultsUnder similar conditions, the maximum equivalent stress (MES) on titanium alloy fixations was greater than that on absorbable plate materials. Both under static and physiological conditions, all FEM groups ensured structural stability of the system, with material stresses remaining within safe ranges. Compared to CLOA, DLOD, which involves the removal of the lateral orbital wall, altered stress conduction, resulting in an increase of MES and maximum total deformation (MTD) by 1.96 and 2.62 times, respectively. Under a horizontal load of 50 N, the MES in FEM/DLOD exceeded the material's own strength, with an increase in MES and MTD by 3.18 and 6.64 times, respectively, compared to FEM/CLOA. Under a vertical force of 50 N, the MES sustained by each FEM was within safe limits. Bone flap rotation angles remained minimally varied across scenarios. During follow-up, the 12 patients validated in this study did not experience complications related to the internal fixation devices. ConclusionUnder static or physiological conditions, various fixation methods can effectively maintain stability at the orbitotomy site, and absorbable materials, with their smoother stress transmission properties, are more suited for application in CLOA. Among titanium plate fixations, single titanium plates can better withstand vertical stress, while double titanium plates are more capable of handling horizontal stress. Given the change in the orbital mechanical behavior due to DLOD, enhanced fixation strength should be considered for bone flap repositioning.

Current Concepts in Management of Distal Femur Fractures

Recent studies report the overall incidence of distal femur fractures as 8.7/100,000/year. This incidence is expected to rise with high energy motor vehicle collisions and elderly osteoporotic fractures in native and prosthetic knees keep increasing. These fractures are more common in males in the younger age spectrum while females predominate for elderly osteoporotic fractures. Surgical treatment is recommended for these fractures to maintain articular congruity, enable early joint motion and assisted ambulation. Over the last two decades, development of minimally invasive and quadriceps sparing surgical approaches, availability of angle stable implants have helped achieve predictable healing and early return to function in these patients. Currently, laterally positioned locked plate is the implant of choice across all fracture patterns. Retrograde with capital implantation of intramedullary nails with provision for multiplanar distal locking is preferred for extra-articular and partial articular fractures. Even with these advancements, nonunion after distal femur fracture fixation can be as high as 19%. Further recent research has helped us understand the biomechanical limitations and healing problems with lateral locked plate fixation and intramedullary nails. This has lead to development of more robust constructs such as nail-plate and double plate constructs aiming for improved construct strength and to minimise failures. Early results with these combination constructs have shown promise in high risk situations such as fractures with extensive metaphyseal fragmentation, osteoporosis and periprosthetic fractures. These constructs however, run the risk of being over stiff and can inhibit healing if not kept balanced. The ideal stiffness that is needed for fracture healing is not clearly known and current research in this domain has lead to the development of smart implants which are expected to evolve and may help improve clinical results in future.

Meta-analysis of the clinical efficacy and safety of single versus dual plate in the treatment of comminuted distal femur fractures.

Through meta-analysis, this study aims to comprehensively evaluate the efficacy of single-plating and double-plating in the treatment of comminuted fractures of the distal femur. Computer searches of PubMed, Cochrane Library, Embase, China National Knowledge Infrastructure (CNKI), China Biology Medicine (CBM), VIP, and Wanfang digital journals were performed, and the timeframe for the searches was from the establishment of each database to July 2023 for each of the databases. Meta-analysis was performed using RevMan 5.4 software provided by the Cochrane Library, and the review process was registered in the PROSPERO database. A total of ten studies were included for statistical analysis. One randomised controlled study and nine retrospective cohort studies with a total of 563 patients were included. The double-plate group was superior to the single-plate group in terms of knee mobility at 6 months postoperatively, overall postoperative complications, and the rate of healing of knee deformity. However, it increased the operation time and intraoperative bleeding, and the difference between the two groups was statistically significant (P < 0.05). There was no significant difference between the two groups in terms of excellent knee function rate, fracture healing time, plate fracture, postoperative infection, delayed fracture healing, and non-union (P ≥ 0.05). Double plate fixation for comminuted fractures of the distal femur can improve knee mobility at 6 months postoperatively, reduce overall postoperative complications, and decrease the incidence of malunion healing. However, it increases operative time and bleeding. Randomised studies are needed to provide strong evidence in the future.

Novel double deck gate field plate structure on a normally-off AlGaN/GaN HEMT- An extensive analysis

A novel double deck gate field plate structure on a normally-off AlGaN/GaN HEMT is proposed and compared with the conventional no field plate structure. Several passivation materials with relative permittivity (εr) ranging from 3.9 to 22 is taken into consideration to study the breakdown and DC characteristics. The implementation of field plate along with a higher εr material helps in improving breakdown voltage (VBr) as they both decrease the electric field at the gate's drain edge. Aiming device optimization several field plate configurations are studied including tri field plate structure, dual field plate structures and single gate FP structure. Extensive analysis in these structures are done with different lengths of the field plates and distance between source and drain. Distance between source and drain (LSD) is varied from 8.4 to 13.4 μm, source FP lengths (LS_FP) varies from 1 to 7 μm, gate FP lengths (LG_FP) varies from 0.9 to 2.3 μm and drain FP lengths (LD_FP) varies from 0.2 to 4.9 μm. In all scenarios with varying LSD, VBr rises with increasing LSD. For source, gate and drain FP lengths variation, VBr decreases as it gets longer because the electric field becomes very high. As the distance between the FP edge and the drain becomes narrower with increase in FP lengths, the breakdown occurs at lower voltage. At LSD 13.4 μm, this novel double deck gate FP structure with conventional drain field plate structure gives highest VBr of 1660 V and a small Ron of 2.39 Ω mm as compared to other structures. It also outperforms the other three structures in FT (9.84 GHz) at this particular LSD. Analysis of the simulated structures shows that the union of gate-drain field plate boosts the VBr while decreasing the Ron, resulting in improved electrical performance and a wider application range.

Thermal performance enhancement of gas filled double glazed flat plate solar collectors

The aim of this investigation is to study the effect of using two different trapped gasses at the same time within two glazing and absorber plate in which the inner layer adjacent to the absorber plate was filled with Helium and the outer layer was filled with Argon to augment the heat gain and prevent heat missing that lead to 12.39 % enhancement in the performance of Gas Filled Double Glazed Flat Plate Solar Collector (GFDGFPSC) in comparison to Air Filled DGFPSC. As Collectors have to be installed at the best angle to gain the maximum irradiation, variation of DGFPSC's angle and both optical thicknesses were evaluated. On the basis of findings, AFDGFPSC's efficiency increased to more than 37 % when the angle was 60° while it was about 31 % at the angle of 30°. Efficiency of the Gas Filled DGFPSC increased a bit lower from 46.7 % to 49.6 % as the angle increased from 30 to 60°. Variations of both inner and outer optical thicknesses were examined at the angle of 60° where growth of the outer optical thickness made low effect on GFDGFPSC performance whereas inner optical thickness increment boosted the useful energy reservation and thus thermal efficiency up to 53.44 %.

Résultats à moyen terme des prothèses totales de coude dans le traitement des fractures gériatriques de l’humérus distal

Background: While double plate fixation is the gold standard treatment for distal humerus fractures in the general population, it is the source of many complications in the elderly. Total elbow arthroplasty (TEA) has been proposed as an alternative treatment, with satisfactory short-term functional outcomes. However, little is known about the longevity of the implant and the mid- and long-term complications of this procedure.Materials and methods: A total of 58 TEAs were performed in 57 patients with comminuted distal humerus fractures between September 2008 and September 2019. All patients were clinically (ranges of motion, Mayo Elbow Performance Score [MEPS] and Disabilities of the Arm, Shoulder and Hand [QuickDASH] functional scores) and radiographically assessed. The minimum follow-up was 2 years, and the mean follow-up was 4.7 years.Results: The overall complication rate was 20.7%, with ulnar nerve damage, complex regional pain syndrome, and severe stiffness being the main complications. The mean MEPS was 85.3, and the mean QuickDASH was 28.1. The mean flexion was 122°, and the mean extension was -23.5°. There were no prosthetic revisions. Of these patients, 17% had radiolucent lines, and 13% had bushing wear at the last follow-up.Discussion: TEA is an effective technique for treating comminuted distal humerus fractures in the geriatric population. The prosthesis's mid-term survivorship was highly satisfactory, with a complication rate that remained low and was generally lower than that of osteosynthesis, with identical functional outcomes. TEAs are indicated in elderly patients, for whom maintaining the fullest possible autonomy is paramount. Our findings suggest that TEAs have sufficient longevity to guarantee a functional, pain-free elbow with no need for reoperation.Level of evidence: IV; case series.

Cyclic loading behavior of novel internally stiffened double steel plate shear wall

In this paper, a novel Internally Stiffened Double Steel Plate Shear Wall (ISD-SPSW) is proposed based on the concept of improving the buckling mode of steel plates and enhancing the lateral resistance of steel plate shear wall (SPSW). The ISD-SPSW consists of double outer steel plates on both sides, inner stiffened rib plates, and boundary members. The seismic behavior of ISD-SPSW was investigated through tests and numerical simulations. Five ISD-SPSW specimens with different heights of the wall, thickness of the outer steel plate and boundary member, and different numbers of internally stiffened steel plates were investigated in cyclic loading tests. The performance indexes such as hysteresis curves, strain curves, and skeleton curves of ISD-SPSW were obtained. The finite element model of ISD-SPSW was established and verified by the test results. The test results reveal two distinct failure modes for the ISD-SPSW. The first mode involves the failure of diagonal tension bands, which is a result of local buckling in the outer steel plates. The second mode is characterized by the overall instability of the shear wall, resulting from the out-of-plane deformation of the boundary members. Lowering the height of the wall can markedly improve the load-bearing capacity and out-of-plane stability of ISD-SPSW. Increasing the thickness of the outer steel plate can improve the ultimate load-bearing capacity, but has adverse effect on the boundary members. Reducing the thickness of the boundary member can significantly reduce the load-bearing capacity and seismic performance. Reducing the number of inner stiffened rib plates decreases the shear load-bearing capacity and energy dissipation capacity. The ductility coefficient of most specimens is greater than 3.0, indicating that the ISD-SPSW has good ductility. In addition, the results of the established finite element model are in good agreement with the test results, which verifies the accuracy of the model.

Experimental and numerical study on the blast performance of the corrugated double steel plate concrete composite wallboard under blast loads

The corrugated double steel plate concrete composite wallboard (CDSCW) exhibits superior axial compressive load-bearing capacity, lateral flexural stiffness, impact resistance, and seismic performance compared to the traditional reinforced concrete wallboard and plane double steel plate concrete composite wallboard (PDSCW). Therefore, it has great potential application in offshore engineering and military engineering. This study designs and fabricates two types of CDSCW specimens. Firstly, a comparative analysis is conducted to examine the damage patterns and dynamic responses of the two specimens under near-field explosion experiments. Secondly, the damage mechanisms and explosion response of CDSCW and PDSCW subjected to close-in explosions are numerically investigated by using ANSYS/LS-DYNA, and the results are then compared with experimental findings. Parameter analysis is performed to assess the influence of concrete thickness, steel plate thickness, and explosive charge on the blast resistance of CDSCWs. Furthermore, a nonlinear resistance equation and an equivalent single degree of freedom (ESDOF) theoretical model for simply supported beams is established to predict the dynamic response of CDSCWs under near-blast loads. This theoretical model considers the constitutive model of bilinear materials and the effect of plastic hinges. The reliability of the proposed theoretical model is verified by comparing the residual deflection of CDSCWs obtained from explosion tests with validated numerical simulation results. The results demonstrate that the CDSCWs, with the same concrete and component dimensions (length, width), exhibit greater flexural stiffness and superior energy dissipation capacity subjected to close-in explosion. Moreover, their blast resistance significantly surpasses that of PDSCWs. In particular, an increase in corrugation depth effectively improves the blast resistance of CDSCWs. The dynamic response equations, based on the established elastic-plastic model and primarily considering bending deformation of the components, precisely predict the dynamic response of simply supported CDSCWs under near-blast loads. consequently, these findings can provide a robust foundation for further research and the design of blast-resistant structures.

Application of double plate fixation combined with Masquelet technique for large segmental bone defects of distal tibia: a retrospective study and literature review.

There is no effective consensus on the choice of internal fixation method for the Masquelet technique in the treatment of large segmental bone defects of the distal tibia. Thus, the study aimed to investigate the outcomes of the Masquelet technique combined with double plate fixation in the treatment of large segmental bone defects. This was a retrospective study involving 21 patients with large segmental bone defects of the distal tibia who were treated between June 2017 and June 2020. The length of bone defect ranged from 6.0cm to 11cm (mean, 8.19cm). In the first stage of treatment, following complete debridement, a cement spacer was placed to induce membrane formation. In the second stage, double plate fixation and autologous cancellous bone grafting were employed for bone reconstruction. Each patient's full weight-bearing time, bone healing time, and Iowa ankle score were recorded, and the occurrence of any complications was noted. All patients were followed up for 16 to 26months (mean, 19.48months). The group mean full weight-bearing time and bone healing time after bone grafting were 2.41 (± 0.37) months and 6.29 (± 0.66) months, respectively. During the treatment, one patient had a wound infection on the medial side of the leg, so the medial plate was removed. The wound completely healed after debridement without any recurrence. After extraction of iliac bone for grafting, one patient had a severe iliac bone defect, which was managed by filling the gap with a cement spacer. Most patients reported mild pain in the left bone extraction area after surgery. The postoperative Iowa ankle score range was 84-94 (P < 0.05). In this cohort, 15 cases were rated as "excellent", and 6 cases as "good" on the Iowa ankle scoring system. The Masquelet technique combined with double plate fixation is a safe and effective method for the treatment of large segmental bone defects of the distal tibia.

Usefulness of double plate fixation after failed ORIF for clavicle shaft fracture

PurposeWe aimed to evaluate the clinical and radiological outcomes of double plate fixation for failed clavicle shaft fracture surgery.Materials and methodsWe analyzed 14 patients who underwent double plate fixation due to plate failure after clavicle shaft fracture surgery from March 2016 to March 2021. The study used 3.5 mm locking compression plates for superior clavicle and anterior reconstruction in all patients. In addition, moldable allograft bone was used to fill the bone defect. Clinical and radiological evaluation was performed immediately, at 2 and 4 weeks, and 3, 6, 9, and 12 months postoperatively. The visual analog scale (VAS), University of California at Los Angeles (UCLA) shoulder scale, and American Shoulder and Elbow Surgeons (ASES) scores and range of motion of the shoulder were evaluated as clinical results. For radiological evaluation, anteroposterior, caudal, and cephalad views of both clavicles were used. Successful bone union was defined as complete adjoining of the fracture site through callus formation.ResultsSuccessful bone union was achieved in all patients, and the mean time to bone union was 16.7 ± 1.2 weeks (range, 12–24 weeks).Statistically significant improvement in forward flexion and external and internal rotation was observed from 135.5° ± 6.3, 45.2° ± 5.3, and 13° ± 2.3 preoperatively to 157.0° ± 9.3, 68.7° ± 6.3, and 9.8° ± 3.1 at the final follow-up, respectively.The VAS score improved from an average of 6.2 ± 2.8 preoperatively to 1.3 ± 0.7 at the final follow-up, which was statistically significant (P = 0.018). In addition, the ASES score significantly increased from a mean of 52.1 ± 6.3 points preoperatively to 83.6 ± 7.8 points at the final follow-up (P = 0.001).The average UCLA shoulder score was 16.7 ± 1.4 and 31.4 ± 2.2 points preoperatively and at the final follow-up, respectively, which was statistically significant (P = 0.001).ConclusionDouble plate fixation has shown good results after failed open reduction and internal fixation (ORIF) for clavicle shaft fractures. Therefore, in complicated situations after ORIF, double plate fixation is considered a surgical treatment option.

Investigation on heat transfer performance of flat plate micro-heat pipe phase change heat storage/release device

In the domains of low/zero carbon energy, the ship energy storage system, coupled with phase-change storage and release technology, holds significant importance. The utilization of a flat micro-heat pipe as the primary heat transfer element prompts the development of a test platform and a transient heat transfer model for the heat storage device. This is in response to existing challenges such as a single structure, poor temperature uniformity, and low thermal efficiency in current heat storage technology. The study delves into the impact of varying temperatures and flow rates of heat transfer fluids on the overall performance of heat storage devices and heat transfer efficiency. The findings highlight that the staggered double plate micro-heat pipe structure can enhance total heat storage by 11%, average heat storage power by 19%, and heat storage efficiency by 21% compared to the heat storage device with a single flat micro-heat pipe structure. It becomes evident that the heat storage device with the staggered double heat pipe structure outperforms its counterpart. Additionally, Temperature and flow velocity play pivotal roles in determining the heat transfer performance of phase change materials. As the temperature difference between the heat transfer fluid and the phase change material increases, both the phase transition rate and the equivalent Nusselt number also rise, providing a crucial foundation for examining the heat transfer characteristics of phase change materials during different stages of phase transition.

Strategy for simulating high-speed crack propagation in 3D-plate structures based on S-version FEM

Plate structures serve as the fundamental components of many large structures; therefore, dynamic crack propagation in plates is a significant safety concern. This paper proposes a novel strategy based on the s-version finite element method (s-method) for simulating high-speed crack propagation in a 3D plate structure. We employed a combination of the nodal force release technique and local mesh update method to simulate a dynamically propagating crack front. The global mesh was generated based on the entire domain geometry without considering crack propagation, which significantly simplified the mesh generation procedure, whereas the local mesh was generated only in the vicinity of the crack front with fine elements to ensure high accuracy. In the proposed strategy, the local mesh completely covered the crack front beyond the surface of the 3D plate structure. Such an incompatibility between the surface of the target domain and boundaries of the local mesh causes non-negligible errors in the conventional s-method. Hence, we propose an approach based on Heaviside enrichment to eliminate these errors. To investigate the effectiveness of the proposed strategy, numerical examples to analyse the experimental results of high-speed crack propagation in double cantilever beam-type plate specimens made of polymethyl methacrylate are presented. The numerical results demonstrated the effectiveness of the proposed strategy for simulating high-speed crack propagation in 3D plate structures. Therefore, the proposed strategy has the potential to serve as a fundamental numerical framework for simulating dynamic crack propagation in engineering structures.

Finite element analysis of the stability of retrograde intramedullary nail and plate-screw combinations for periprosthetic femoral fractures following total knee replacement.

Periprosthetic fractures following total knee replacement are rare but challenging. The goal of the treatment is to achieve the most stable fixation that allows early mobilization. Therefore, the aim of this study was to evaluate the biomechanical results of the use of different fixation systems in the treatment of distal femur periprosthetic fractures with finite element analysis. A total knee prosthesis was implanted in Sawbone femur models. A transverse fracture line was created in the supracondylar region and was fixed in four different groups. In group 1, fracture line fixation was fixed using retrograde intramedullary nailing. In group 2, fixation was applied using a lateral anatomic distal femoral. In group 3, in addition to the fixation made in group 1, a lateral anatomic distal femoral plate was used. In group 4, in addition to the fixation made in group 2, a 3.5 mm Limited Contact Dynamic Compression Plate (LC-DCP) was applied medially. Computed Tomography (CT) scans were taken of the created models and were converted to three-dimensional models. Axial and rotational loading forces were applied to all the created models. The least deformation with axial loading was observed in the double plate group. Group 3 was determined to be more advantageous against rotational forces. The greatest movement in the fracture line was found in group 2. The application of the medial plate was determined to reduce the tension on the lateral plate and increase stability in the fracture line. Combining a lateral anatomic plate with intramedullary nailing or a medial plate was seen to be biomechanically more advantageous than using a lateral plate or intramedullary nailing alone in the treatment of distal femoral periprosthetic fractures.

The comparison of single plate and double plate fixation methods for treatment of humeral shaft non-union

The comparison of single plate and double plate fixation methods for treatment of humeral shaft non-union

Mid-term results of total elbow arthroplasties in the treatment of geriatric distal humerus fractures

BackgroundWhile double plate fixation is the gold standard treatment for distal humerus fractures in the general population, it is the source of many complications in the elderly. Total elbow arthroplasty (TEA) has been proposed as an alternative treatment, with satisfactory short-term functional outcomes. However, little is known about the longevity of the implant and the mid- and long-term complications of this procedure. Materials and methodsA total of 58 TEAs were performed in 57 patients with comminuted distal humerus fractures between September 2008 and September 2019. All patients were clinically (ranges of motion, Mayo Elbow Performance Score [MEPS] and Disabilities of the Arm, Shoulder and Hand [QuickDASH] functional scores) and radiographically assessed. The minimum follow-up was 2years, and the mean follow-up was 4.7years. ResultsThe overall complication rate was 20.7%, with ulnar nerve damage, complex regional pain syndrome, and severe stiffness being the main complications. The mean MEPS was 85.3, and the mean QuickDASH was 28.1. The mean flexion was 122°, and the mean extension was −23.5°. There were no prosthetic revisions. Of these patients, 17% had radiolucent lines, and 13% had bushing wear at the last follow-up. DiscussionTEA is an effective technique for treating comminuted distal humerus fractures in the geriatric population. The prosthesis's mid-term survivorship was highly satisfactory, with a complication rate that remained low and was generally lower than that of osteosynthesis, with identical functional outcomes. TEAs are indicated in elderly patients, for whom maintaining the fullest possible autonomy is paramount. Our findings suggest that TEAs have sufficient longevity to guarantee a functional, pain-free elbow with no need for reoperation. Level of evidenceIV; case series.

Clinical effect analysis of different treatment schemes for children with ulnar and radial double fractures.

The objective of the study is to evaluate the safety and efficacy of three different treatment methods for pediatric ulnar and radial double fractures. 120 children with ulnar and radial double fractures were included in the study. According to the different treatment plans, children were divided into three groups: manual reduction, splint external fixation, double elastic intramedullary fixation, and double plate fixation. Surgical indicators, radiological results, clinical efficacy, and complications were evaluated and compared among the groups. The average hospital stay and operation time were significantly longer in the double plate internal fixation group compared to the other two groups. The double elastic intramedullary nailing group showed a higher fracture healing rate at 3 months compared to the other groups. There were no significant differences in clinical efficacy among the three groups. Complications were observed in all groups but did not show significant statistical differences. Double elastic intramedullary nailing fixation demonstrated favorable outcomes in terms of surgical indicators and fracture healing rates for pediatric ulnar and radial double fractures.

Design Method for Local Buckling Resistance of Double Steel Plate–Concrete Composite Walls with Stiffening Ribs and Tie Plates

An ordinary double steel plate–concrete composite wall (ODSC wall) is composed of core concrete, the faceplates, and shear connectors such as studs, etc. Based on an ODSC wall, a new type of stiffened double steel plate–concrete composite wall (SDSC wall) is conceived by incorporating additional stiffeners and tie plates on the internal surface, which aims to improve the local stability of the faceplates. In the authors’ previous study, a series of axial compression tests were conducted on the SDSC walls. The SDSC walls in the test showed better mechanical performance, as the presence of stiffeners changed the buckling deformation mode and significantly improved the corresponding local buckling stress and ultimate strength. In this paper, a comprehensive summary of the prior research on SDSC walls is provided, and the effect of the constructive parameters on the local stability is discussed. The results reveal that the modified formula of the critical stress can degrade to the Euler formula when the stiffener-to-stud spacing ratio (i.e., a/B ratio) approaches infinity. What is more, the analysis model is also applicable for DSC walls with enclosed side plates, and the proposed formula can predict the buckling stress of the SDSC walls with different a/B ratios. In addition, according to the analysis of the numerical simulation, a design approach for SDSC walls to prevent local buckling is provided, which is applicable in practical engineering applications.