Costal Margin Research Articles

General dermatology and dermatology in primary healthcare.

The “costal fringe” refers to a linear arrangement of venous telangiectasias distributed along the anterolateral costal margins. The costal fringe is typically observed in older adults, although it has also been reported in younger patients. On the other hand, linear telangiectasias, arranged in a broad, crescent-shaped distribution across the chest, are relatively common among homosexual men and show a significant association with HIV infection.

Comparative Analysis of Seventeen Mitochondrial Genomes of Mileewinae Leafhoppers, Including the Unique Species Mileewa digitata (Hemiptera: Cicadellidae: Mileewinae) From Xizang, China, and New Insights Into Phylogenetic Relationships Within Mileewini.

The subfamily Mileewinae in China comprises one tribe (Mileewini), four genera (Ujna, Mileewa, Processina, Anzihelus), and 71 species, yet only 11 mitochondrial genomes have been published. This study aimed to elucidate ambiguous diagnostic traits in traditional taxonomy and examined phylogenetic relationships among genera by sequencing mitochondrial genomes from 16 species. The lengths of the mitochondrial genomes ranged from 14,532 to 15,280 bp, exhibiting an AT content of 77.2%-80.7%, indicative of AT bias. Each genome contains 13 protein-coding genes (PCGs), 22 transfer RNA genes (tRNAs), and 2 ribosomal RNA genes (rRNAs). Notably, the genome of the Xizang endemic Mileewa digitata measures 15,280 bp, with an AT content of 80.7%, 10,941 bp of PCGs, and a 949 bp control region (CR) followed by a 19 bp poly-A tail. Gene arrangement among the 17 genomes mirrors that of other Mileewinae species. Analyses of nucleotide diversity and evolutionary rates indicate purifying selection on PCGs, with atp8 exhibiting the greatest variability and evolutionary rate, whereas cox1 shows the least. Genetic distance studies display minimal separation among Mileewa species, specifically Mileewa nii with Mileewa margheritae and Mileewa rufivena with Mileewa ussurica, as well as the two morphs of Mileewa digitata. Phylogenetic analyses using Bayesian Inference (BI) and Maximum Likelihood (ML) generated six trees, further questioning the monophyly of the genera Mileewa, Ujna, and Processina. The reconstructed ancestral state based on the forewing patch position suggests that the common ancestor of Chinese Mileewini species was situated exclusively on the costal margin, prompting a proposed division of the tribe's species into two categories (genera). This research enriches the understanding of phylogenetic relationships within Mileewinae and contributes to the mitochondrial genome database for this group, paving the way for future taxonomic studies in China.

Influence of Welding Residual Stress on the Structural Behaviour of Large-Span Steel Tube Arch Rib

Influence of Welding Residual Stress on the Structural Behaviour of Large-Span Steel Tube Arch Rib

THE ROLE OF Β2-MICROGLOBULIN IN ASSESSING THE PROGRESSION OF B-CELL CHRONIC LYMPHOCYTIC LEUKEMIA

Introduction. The primary assessment of β2-microglobulin holds significant value in monitoring the dynamics of oncohematological processes, which can serve as a crucial marker for evaluating the baseline condition of patients with B-cell chronic lymphocytic leukemia. Aim: to analyze the levels of β2-microglobulin in patients experiencing progression of B-cell chronic lymphocytic leukemia. Materials and methods. Twenty six patients with progressive B-cell chronic lymphocytic leukemia (CLL) were examined, comprising 12 males (46%) and 14 females (54%). These patients were designated as Group I. The control group (Group II) included 20 healthy individuals aged 23–43 years, consisting of 11 females (55%) and 9 males (45%). In Group I, disease staging was assessed using the Rai-Binet classification: stage II (B) was observed in 18 patients (69.2%), stage III (C) in 4 patients (15.4%), and stage IV (C) in 4 patients (15.4%). Among patients with progressive CLL, hyperplastic syndrome was evaluated, including lymph node enlargement (≥3 cm in diameter) and hepato- or splenomegaly (liver or spleen extending ≥5 cm below the costal margin). General and biochemical blood analyses were conducted, along with measurements of β2-microglobulin levels. Statistical methods were applied to process and analyze the data. Results. In patients with progression of B-cell chronic lymphocytic leukemia (CLL), hematological analysis revealed anemia (hemoglobin <100 g/L) in 6 patients (23.1%) and thrombocytopenia in 8 patients (30.7%). Leukocytosis with leukocyte levels >100 G/L was observed in 4 patients (15.4%) in Group I. Notably, an inverse correlation was identified between β2-microglobulin levels and hemoglobin levels (r = -0.52; p = 0.02). Biochemical analysis showed a reduction in total serum protein to grade 1 according to CTCAE in 2 patients (7.7%), elevated serum creatinine levels, reaching grade 1 according to CTCAE, were observed in 4 patients (15.4%) in Group I. An inverse correlation was found between β2-microglobulin levels and total serum protein levels (r = -0.44; p = 0.02). A direct correlation was also identified between β2-microglobulin levels and serum creatinine levels (r = 0.65; p = 0.04). In 9 (34.7%) patients of group I, the concentration of β2-microglobulin in blood serum exceeded the level of 5 mg/l. It is important that all 100% (9/9) of patients in this category were found to have hyperplastic syndrome. In addition, 33.3% (3/9) of patients had a combination of lymphadenopathy, splenomegaly, and hepatomegaly (liver +5 cm below the edge of the costal arch), 55.6% (5/9) had a combination of two factors, in 11, 1% (1/9) hyperplastic syndrome was characterized by an increase in the size of peripheral lymph nodes by more than 3 cm. The average level of β2-microglobulin was 6.24 mg/l in patients with progression of B-cell chronic lymphocytic leukemia of group I, of which 9 patients had a level of β2-microglobulin greater than 5 mg/l. Conclusion. The level of β2-microglobulin corresponds to the severity of progression of B-cell chronic lymphocytic leukemia and correlates with the level of anemia, hypoproteinemia, hypercreatinemia, and the severity of hyperplastic syndrome.

Research on Construction Technology of Steel Structure Tie Rod Arch Bridge with Less Support

In order to explore the installation method of the steel box tie-rod arch bridge across the canal, in order to meet the requirements of rapid installation under the condition of near the existing diagonal bridge. Based on qingshuihe Bridge of G50 Shanghai-Chongqing Expressway, the installation technology of steel box pole arch bridge is studied by combining theoretical analysis and field practice. This paper analyzes the construction problem of Qingshuihe Bridge and proposes an construction method of small supports and large sections. The oblique asymmetric beam arch is designed to avoid the influence on the channel headband. The installation process of bridge deck system is optimized, the bending moment of steel beam is effectively reduced, and the temporary span of beam beam installation is improved. The finite element analysis shows that the beam, arch ribs and other components are in good stress condition according to the asymmetric deformation of the boom force, and ensure the smooth installation of the beam and bridge deck.

Anatomy of the Ribs, Sternum, and Costal Margin.

The ribs, sternum, and costal margin provide a rigid, but flexible chest wall that functions to provide protection to the vital cardiothoracic organs, while also allowing for varying levels of respiration based on physiologic need. The latter function is accomplished through various muscular attachments and rib articulations with both the axial spine posteriorly and the sternum anteriorly. The accessory muscles of inspiration rely on the downward slope and outward curve of each rib, which when contracted move the ribs upward and outward, in turn forcing the sternum anterior and increasing the thoracic volume. Ribs are also classified as true, false, or floating based on their attachment anteriorly to the costal cartilage and sternum. Ribs 1-7 are considered true ribs as their costal cartilage directly articulates with the manubrium and sternum. Ribs 8-10 are considered false ribs because their costal cartilage connects to the cartilage of the immediately superior rib instead of the sternum itself. This complex cartilaginous structure is referred to as the costal margin, which provides attachments for the diaphragm and various abdominal muscles. Although historically thought to be a consistent structure, its variable nature has recently been defined in cadaveric studies. Ribs 11 and 12 are considered floating ribs because they have rudimentary cartilage caps and are not attached to the sternum at all. The sternum comprises the manubrium, body, and xiphoid process. Each component has differing mobility, muscle attachment, and function.

Rib and Sternum Nonunions: Diagnosis and Treatment and Awareness of Other Potential Posttraumatic Pathology.

As the operative management of acute, chest wall, skeletal injury escalates throughout the world, it has become commonplace for patients with posttraumatic conditions to present with clinical reconstructive challenges as well. In addition, it is becoming clear that rib nonunions are not rare, likely more than 5% of rib fractures. No subspecialty is better equipped to address such painful conditions than orthopaedic surgery. Likewise, there are a plethora of other posttraumatic problems that patients face, from intercostal neuralgia, pleural herniation, rib synostosis, and costal margin and sternal injuries that do not heal properly, which require treatment solutions. This emerging new field of surgery is optimized by an interdisciplinary approach, between general and orthopaedic trauma surgeons, and between thoracic, anesthesia, and rehabilitation specialists. This article emphasizes the workup and operative treatment of painful rib and sternal nonunions, in particular, and familiarizes the orthopaedist with other cold skeletal trauma in general. From the distinctive history and physical examination of the patient with a rib psuedoarthrosis to proper diagnostic studies, the surgeon is led through a principled approach to nonunion surgery, inclusive of autogenous graft harvest to provide both biologic and mechanical variables to bear in the successful treatment of this condition.

Aerodynamic parameters investigation of simplified CFD-based CFST truss arch rib model

As the span of long-span concrete-filled steel tube (CFST) truss arch bridges continues to increase, their sensitivity to wind significantly enhances, making the study of arch rib stability under wind loads increasingly important. However, current standards for aerodynamic parameters of CFST truss arch bridges are still incomplete, only providing calculated values for the drag coefficients of local bridge components. This study utilizes Computational Fluid Dynamics (CFD) as the primary research tool, combined with existing wind tunnel tests of arch rib segments, to propose a two-dimensional simplified model of a CFST truss arch rib and validate its effectiveness in computing aerodynamic parameters. Based on this model, parametric studies were conducted on the aspect ratio of a single arch rib section and the aerodynamic interference effects between double arch ribs. The research findings indicate that for long-span CFST truss arch rib sections, the empirical formula values specified in the standards are unsafely low. The overall drag coefficient of the arch rib segment shows a trend of initially increasing and then decreasing with the aspect ratio (H/B), peaking at an H/B of 1.5 before continuously declining. It is recommended that the design value for the arch rib H/B be between 1.75 and 2.5. Additionally, once the spacing ratio (L/B) between double arch ribs exceeds 2, the overall drag coefficient of the arch ribs no longer changes with increased spacing. For long-span CFST truss arch bridges, the wind load on the downstream arch ribs can be considered using a shielding coefficient of 0.53 from the upstream arch ribs.

Rib fracture characteristics increasing the risk of hemothorax: a multicenter study

The precise assessment of hemothorax risk resulting from a rib fracture is not feasible. CT images, patient characteristics, and clinical experience are utilized in daily practice to assess risk intuitively. This study aimed to identify specific markers on CT images that can predict the risk of hemothorax. The study was retrospectively conducted between May 2021 and December 2023 at three different centers. Patients diagnosed with hemothorax at the initial assessment or during follow-up were identified among those being followed for rib fractures. An investigation was carried out to examine the relationship between the number of rib fractures, displacement status, and the location of the fracture on the rib arch with the risk of hemothorax. Of the 273 patients included in the study, 201 (73.6%) were male. The mean age was 53.9 ± 17.27 (19–93) years. Lateral (p = 0.029) and posterior (p < 0.001) location of the fracture and displacement of at least one fracture (p = 0.003) were associated with an increased risk. There was a significant correlation between the number of rib fractures and the risk of hemothorax (p < 0.001). The optimal cut-off for the number of rib fractures associated with a high risk of hemothorax was determined to be 4. Anatomical characteristics of a rib fracture can be useful to assess the risk of hemothorax practically in patients with thoracic trauma especially in emergency rooms. Patients with four or more rib fractures, at least one displaced rib fracture, and lateral and posterior rib fractures should be followed more carefully for hemothorax.

Research on the Safety and Stability Evaluation for a New Type of Prefabricated Aqueduct in the Construction Stage

To address the issue of regional water resource scarcity, water diversion projects have been constructed worldwide. As an essential lifeline project, the prefabricated aqueduct is prevalently utilized in cross-regional water transfer and diversion projects. This paper was based on the prefabricated aqueduct project, which adopted fabricated technologies including the connection technology among the gravity pier, the prefabricated arch ribs, and the prefabricated bent frame columns. The PHC piles, bearing platforms, bent frame columns, arch ribs, and groove bodies were all prefabricated components that were transported to the site for installation. The connections of the prefabricated aqueduct employed to link different components were of such crucial significance that their safety and stability determined whether the overall structure would be compromised. Therefore, the main objective of this paper was to examine the stress and deformation of this prefabricated aqueduct to prevent the occurrence of security risks throughout the entire construction stage. The finite element model was established in Midas Civil, and the entire construction stage was simulated and analyzed. Coupled with on-site monitoring, the stress and deformation of the prefabricated aqueduct were evaluated. The results indicated that the tensile stress, the compressive stress, the vertical displacement, and the lateral displacement of each part of the prefabricated aqueduct met the requirements of the standard, suggesting that the overall structure with the applied connection technology was in a safe and stable state throughout the entire construction stage.

ASSOCIATION OF RISK FACTORS WITH THE INCIDENCE OF LUMBAR PAIN SYNDROME IN PHYSIOTHERAPISTS AT THE CLINIC FOR PHYSICAL MEDICINE AND REHABILITATION

Introduction: Lumbar pain syndrome encompasses various entities manifested by pain, muscle tension, or discomfort between the lower rib arch and the lower gluteal fold, with or without radiation to the leg.Aim: To examine the association of existing risk factors with the incidence of lumbar pain syndrome in physiotherapists.Subjects and Methods: The research was designed as a cross-sectional study and conducted at the Clinic for Physical Medicine and Rehabilitation, University Clinical Hospital Mostar. The study included physiotherapists of both genders and all age groups who did not have a previous history of spinal disease and had more than one year of work experience. Data were collected through anonymous surveys, and the modified Nordic Questionnaire for musculoskeletal symptom analysis was used as the research instrument. This questionnaire consists of four parts: socio-demographic data, healthcare provision, lower back pain, and job satisfaction.Results: The prevalence of lumbar pain in the last 12 months was around 94.0%. The study involved 56 participants, most of whom were female, with the majority being in the 31-40 age group with higher education. Males were slightly overweight, and the duration of lumbar pain was associated with the gender of the participants.Conclusion: Participants who lifted heavier loads experienced significantly more lumbar spine pain, while the duration of work experience was not significantly associated with the incidence of lumbar pain syndrome. Keywords: lower back pain, risk factors, physical activity, daily life activities, physiotherapists

In-plane stability behaviours of concrete-filled steel tubular catenary arches under different loading conditions

Concrete-filled steel tubular (CFST) catenary arches, renowned for their superior loading-bearing efficiency due to the alignment of the arch axis with the thrust line, have become the predominant choice for large-span arch bridges over the past decade. However, research on CFST catenary arches remains limited, with most studies focusing on the in-plane strength of circular and parabolic arches. And the existing design methods are tailored to a narrow range of loading conditions, which raises concerns about their applicability to CFST catenary arches. Therefore, this paper addresses this gap by designing and testing six CFST catenary arches under three different loading conditions (quarter-point concentrated load, mid-span concentrated load, and five-point concentrated loads). The failure modes, load-displacement curves, cross-sectional strain and stress development, and confinement effects were compared and analysed among the loading conditions. Additionally, the finite element (FE) models using beam elements were developed and verified against the test results to conduct a parametric analysis. The influence of arch axis coefficient, slenderness ratio, rise-to-span ratio, and steel ratio on the in-plane strength of the CFST catenary arches under seven different loading conditions was discussed. Finally, by accounting for the non-uniform distribution of internal forces along the arch rib, a lower-bound design formula for the in-plane strength of CFST catenary arches under various loading conditions was proposed, and comparisons with numerical results show that the proposed method can provide conservative predictions.

A novel method for calculating the ultimate bearing capacity of in-service RC arch bridges using sectional constitutive relation

Ultimate bearing capacity is the main basis for evaluating the safety state of in-service reinforced concrete (RC) arch bridges. However, current evaluation methods require a lot of cost to handle the material nonlinearity problem, thereby failing to efficiently addressing such a tough issue. To this end, a novel method for calculating the ultimate bearing capacity of in-service RC arch bridges is proposed. This method accelerates the material nonlinear analysis by the sectional constitutive relation, which avoids the computational intensiveness in conventional methods and may provide a quick solution for structural safety assessment. Firstly, considering the arch axis deviation, temperature change and arch rib damage, the geometric nonlinear differential equation is established, and the real internal force and deformation of the structure are obtained by spline function and Newton–Raphson method. On this basis, the sectional stiffness identification method of in-service arch bridges is developed, in which the identified stiffness is taken as the input parameter. Then, a practical formula of the sectional constitutive relation is proposed to accelerate the material nonlinear analysis based on the fiber model. Finally, the practical formula of the sectional constitutive relation is combined into the geometric nonlinear analysis of arch bridges, by which the double nonlinear analysis of in-service arch RC bridges is fast realized. The effectiveness and superiority of the proposed method is verified experimentally and numerically, and the main factors affecting the service safety of arch bridges are revealed through parameter analysis. The results show that the proposed method can improve the calculation efficiency significantly while maintaining the same accuracy as the traditional method. In numerical validation, the relative calculation error is only 2.08 %, and the total calculation time is only 1/25 of the finite element method.

BN SO46 - PANDORA's BOX- When anatomy trumps the pathology

Abstract Background Obturator hernias are usually attributed to elderly females presenting with small bowel obstruction. We present a case of an elderly gentleman with severe Kyphoscoliosis presenting with small bowel obstruction. His past medical history included Ischaemic Heart Disease with stents in the coronary arteries and on dual antiplatelets. His Kyphoscoliosis precluded him from being able to lie flat on his back. The spinal deformity as revealed in the CT scans proved challenging to position him dsafely for surgery. The lack of access between costal margins and the pelvis meant that surgical access with Laparoscopy was going to be impossible. Method After initial resuscitation, he underwent CT scan of his Chest, abdomen and pelvis which revealed an obstructed Obturator Hernia on the left side with small bowel obstruction. The CT was also concerning for the Anaesthetists due to the challenge posed by the severe Kyphoscoliosis. After fibreoptic intubation, abdomen was accessed through a transverse muscle cutting incision, at the level of the umbilicus. The Obturator membrane was approached from above and the hernia was reduced. The obstructed small bowel was viable and the defect in the obturator membrane was closed with No1 Ethibond sutures. The abdomen was closed with mass closure. Results Patient had a smooth post operative period and was discharged home after 2 weeks. Obturator hernias are notorious for their occult presentation. Unless the patient is scanned with CT imaging, it is impossible to make the diagnosis although clinical signs like Howship- Romberg sign may be present with pain on internal rotation of the hip, as a result of irritation of the Obturator nerve. Obturator Neuralgia may be elicited with positive Hannington- Kiff sign, which is an absence of absent adductor reflux in the thigh. Conclusion Obturator hernias are typically seen in skinny old females. When presenting with small bowel obstruction, Obturator herniae are challenging both in terms of diagnosis as well as in management. In our case, the challenging anatomy posed greater risk to safe airway control. From surgical view, laparoscopy as a less invasive option was ruled out because of the restricted access. When anatomy is challenging, the Surgeon will be forced to think outside the box and consider access to the abdomen through incisions which are not routinely used. The preoperative imaging shows the challenge posed by the extreme spinal deformity.

Reconstrução toracoabdominal com tela de polipropileno após exérese de osteossarcoma condroblástico em cadela

Osteosarcoma is the main bone neoplasm originating in the costal arches; however, its occurrence is less common than that of appendicular osteosarcoma. Known to be locally invasive and with high metastatic potential, it generally requires multimodal treatment involving aggressive surgery and adjuvant chemotherapy. This study aims to report an unusual case of costal arch osteosarcoma in a one-year-old Pit bull dog, who underwent resection of five ribs aiming at wide tumor resection, with subsequent reconstruction of the thoracoabdominal wall using polypropylene mesh. After surgical resection of the tumor, adjuvant antineoplastic chemotherapy with doxorubicin and carboplatin was performed at 21-day intervals, totaling six cycles. To date, the patient has shown no signs of local recurrence or metastases, with a disease-free period of 16 months.

Analysis and sequence for the cable design and construction in steel arch bridges: lesson learned from Taipei chung-cheng bridge reconstruction project

ABSTRACT The girder, the arch rib and the cables are the three main components of an arch bridge. The girder bears the vertical load of road and bridge’s own weight, and these vertical loads are transmitted through the cables to the bridge’s arch. Together, these three components create the structural balance of an arch bridge. The forces exerted on the cables are crucial in the design of steel arch bridges, making the precise configuration and distribution of the cables essential. Cable stretching methods varies between site conditions and structure type. The cable force ratio iteration method was adopted in the reconstruction of Chung-Cheng Bridge to solve the cable force calculations. The iterative process of the cable force analysis at each stage ensures the cable force align with the original design consideration while also factoring in bridge deck elevation and road smoothness. It was successfully applied during the installation and the tensioning of the steel cables. The Chung-Cheng bridge has since been completed and opened to traffic, and the method was proved to be feasible and accuracy were validated, providing a valuable reference for subsequent cable tension control.

Flexural behavior of reinforced concrete arch ribs

For many years, arch bridges have been celebrated for their striking appearance and structural effectiveness. However, the response of arch bridges to dynamic loadings, particularly during earthquakes, remains poorly understood, and reliable seismic design guidelines are lacking. Previous research has suggested that reinforced concrete (RC) arch ribs may experience flexural yielding at their springings due to the interaction of axial force and bending moment under earthquake loading. To assess the ductile behavior and ensure the adequate performance of RC arch ribs, a comprehensive investigation combining experimental and analytical approaches was conducted in this study, taking into account the influence of high axial load and the hollow section configuration present in RC arch ribs. The test results revealed that all RC arch ribs exhibited a typical flexural failure mode. As the axial load increased, the lateral load bearing capacity also increased, but the displacement ductility decreased significantly. Comparing different section configurations, the RC arch rib specimen with a double-cell boxed section demonstrated higher lateral load bearing capacity but lower displacement ductility compared to the single-cell boxed section, while the energy dissipation capacity was approximately similar for both section configurations.

Rib Alignment Control of Long-Span Arch Bridge in Cable-Stayed Buckle by Multi-Objective Optimization

The construction duration of long-span arch bridges is excessively prolonged due to insufficient closing precision and the non-convergence of traditional cable adjustment calculation methods. This study investigates cable force management in long-span concrete-filled steel tubular (CFST) arch bridges during cable-stayed buckle construction, aiming to improve construction safety and precision in arch rib alignment. Using the Pingnan Third Bridge and Tian’e Longtan Bridge as practical examples, the research develops a multi-objective optimization method for cable forces that integrates influence matrices, constrained minimization, and a forward iterative approach. This method offers a robust strategy for tensioning and cable-stayed buckling, enabling real-time monitoring, calculation, and adjustment during the construction of large-span CFST arch bridges. The results reveal that the iterative approach notably enhances calculation efficiency compared to conventional methods. For instance, field measurements at the Pingnan Third Bridge show a minimal arch closure error of only 3 mm. Additionally, the study addresses concerns about excessive stress in exposed steel tubes during concrete casting. By optimizing the sequence of main arch closure and concrete casting, stress in the exposed steel tube is reduced from 373 MPa to 316 MPa, thus meeting specification requirements. In summary, the multi-objective cable force optimization method demonstrates superior efficiency in determining cable tension and controlling rib alignment during cable-stayed buckle construction of long-span CFST arch bridges.

Surgical management of costal margin rupture associated with intercostal hernia: Evolution of techniques.

Costal margin rupture (CMR) injuries in association with intercostal hernia (IH) are rare and symptomatic and provide a significant surgical challenge. Surgical failure rates up to 60% are reported, and optimal techniques are unclear. We have characterized these injuries and describe the evolution of our surgical management techniques. Patients characterized by the Sheffield Classification where CMR and IH were both present, either CMR-IH or transdiaphragmatic intercostal hernia (TDIH), were identified prospectively, and injury characteristics, patient management, and follow-up data were recorded. Surgical techniques evolved according to patient outcomes from suture repair without and then with extrathoracic mesh, to three iterations of double-layer mesh repair (DLMR). The third iteration involved DLMR with biologic mesh, titanium buttress plates applied to the ribs adjacent to the IH with intercostal nerve-sparing suture placement. Associated surgical stabilization of rib fractures, or surgical stabilization of nonunited rib fractures, was performed when required, with costal margin plate fixation where possible. Of 25 patients with CMR-IH and 11 with TDIH, 25 patients underwent surgery, with 6 reoperations in 5 patients. There were 8 suture repairs and 3 extrathoracic mesh repairs: DLMR was performed in 14 patients (3 Mark [Mk] 1, 5 Mk 2, and 6 Mk 3) with 2, 1, and 0 reoperations, respectively. Costal margin stabilization with titanium plates was successful twice at the level of the seventh but failed twice out of three times at the ninth costal cartilage.Reoperation after a failed mesh repair is particularly challenging and may require the placement of titanium buttress plates, surgical stabilization of rib fractures, and the use of stainless steel wire sutures. Repair of CMR-IH/TDIH is challenging, but experience-based evolution of techniques has led to a durable and reproducible Mk 3 repair. Observational; Level III.

Research on the cross-sectional geometric parameters and rigid skeleton length of reinforced concrete arch bridges: A case study of Yelanghu Bridge

To investigate the influence of cross-sectional parameters and the rigid skeleton length on the structural mechanics behavior of reinforced concrete arch bridges, this study focused on the Yelanghu Bridge with a span of 210 m. The sensitivity of the main arch rib's instability mode to cross-sectional parameters such as width, spacing between adjacent webs, height, and concrete thickness was examined by combining the finite element method and the theoretical derivation. Subsequently, research was conducted on the impact of the rigid skeleton length during construction on the static and dynamic performance of the structure relying on the Midas Civil software. The findings indicate that for the Yelanghu Bridge, the risk of in-plane instability is greater than that of out-of-plane and local instabilities. In-plane instability is most sensitive to the section height and the out-plane instability is most sensitive to the thickness of the roof and floor concrete. Under ultimate load-bearing conditions, the axial force in the critical sections of the bridge increases with the length of the rigid skeleton. The fundamental frequency of the Yelanghu Bridge is approximately 0.32, which is significantly lower than that of more rigid arch bridges but higher than those of structurally softer structures such as cable-stayed or suspension bridges. This indicates that large-span reinforced concrete arch bridges exhibit unique dynamic characteristics and belong to moderately flexible structures.