Vertical Reduction Research Articles

Principle and Logic of Vertical Reduction Repair Double-Ring Breast Reduction.

Secondary reduction mammaplasty poses challenges. This article delves into the reasons and complaints regarding secondary repair following double-ring method and outlines the principle and logic of utilizing vertical incision for repair. A retrospective analysis of patients who underwent secondary reduction mammaplasty in our hospital was conducted. The analysis included baseline demographic data, reasons for consultation, surgical records, and postoperative outcomes. Thirty-five patients (70 breasts) underwent secondary reduction mammaplasty. The mean time between the primary reduction mammaplasty and second procedure was 2.99 years (range, 0.5-15years). The mean weights were 210.49g (range, 42-558g) and 207.91g (range, 6-560g) for left and right mastectomies, respectively. Reasons for secondary reduction mammaplasty include poor shape (flat breasts and pseudoptosis), widened incision scar, persistent macromastia, and bilateral asymmetry. The superior and superomedial vertical techniques are safe, effective, and satisfactory in secondary reduction mammaplasty. This journal requires that authors assign a level of evidence to each article. For a full description of these Evidence-Based Medicine ratings, please refer to the Table of Contents or the online Instructions to Authors www.springer.com/00266 .

Trends in continuity of treatment among children and adolescents living with HIV in 14 districts in South Africa from 2018-2023: A retrospective program analysis

ObjectivesUNAIDS estimates 152,984 children under 15 years living with HIV (C/ALHIV) by 2022 in South Africa. Monitoring the continuity of antiretroviral treatment remains challenging without electronic health records. We explored treatment cohort growth and interruption trends in 14-USAID-PEPFAR-supported districts. MethodsWe reviewed data from 2018 to 2023. We triangulated this data with NAOMI HIV estimates. We used Tableau version 2023.2 for analysis to understand heterogeneity in outcomes. ResultsHIV incidence halved from 4.3 per 1000 in 2017 to 2.5 per 1000 in 2022. HIV testing doubled: 188,371 in FY19Q1 to 399,708 in FY23Q4 while testing positivity declined from 3.3% to 0.7%. Linkage to treatment increased from 67% to 102%, viral suppression increased from 79% to 84%. C/ALHIV treatment cohort started at 82,897 in FY19Q1 and increased to 105,107 in FY20Q2. Subsequently, the cohort decreased to 79,288 in FY23Q4 despite 42,498 initiations and 62,256 returns. ConclusionsThe C/ALHIV treatment and viral suppression increased substantially commensurate with expected trends. Subsequent cohort decline was aligned to vertical transmission reduction, HIV incidence decline, and expected aging. We highlight the inadequacy of the information systems to quantify losses. We underscore a need for resources to enhance program monitoring and interventions to address this gap.

Experimental Study on Vibration and Noise Reduction of Gear Transmission System Based on ISFD

Gear transmission systems are widely used in ship propulsion systems, but, during operations, they produce serious vibration and noise problems, reducing the fatigue life of gears and affecting the performance of ships and the comfort of operators. Taking into account the complex frequencies and vibration components of gear transmission systems, this study conducted wide-band vibration suppression and noise reduction research on a gear transmission system using an integral squeeze film damper (ISFD), providing a novel approach for reducing vibration and noise in gear transmission systems. By conducting a simulation analysis and numerical calculations, the ISFD was analyzed via a static analysis and a dynamic analysis. We developed an experimental platform for reducing vibration and noise in gear transmission systems using sliding bearings, and the experiments were conducted under different speed and load conditions to study the vibration suppression and noise reduction of gears based on the ISFD. The experimental results show that the ISFD has good vibration suppression capabilities for gears at different speeds, with a horizontal vibration reduction of 75.44% and a vertical vibration reduction of 68.48% at 2400 r/min. The ISFD has wide-band vibration suppression capabilities, especially for mesh frequency and twice-mesh frequency, with a vibration reduction of 86.96% or more. Moreover, the ISFD has good vibration suppression capabilities for gears at different load torques, with a reduction of more than 35% in all directions. In addition, the ISFD also has noise reduction capabilities, reducing the gears’ noise by 1.92 dB at different speeds.

High-precision tropospheric correction method for NRTK regions with significant height differences

Abstract In response to the issue of poor network real-time kinematic (NRTK) service performance in regions with significant height differences, an improved tropospheric height correction (ITHC) method is proposed. Precise point positioning (PPP) is employed to compute the troposphere delay at base stations. Subsequently, a tropospheric vertical profile fitting model (TVPFM) is established for the vertical reduction of the troposphere in regions with significant height differences. In this case, the tropospheric errors introduced by the height differences between the base and rover stations can be calculated. Finally, the tropospheric error can be corrected during the generation of virtual observations, ensuring high-accuracy positioning of NRTK rovers. With the troposphere delay computed based on the PPP approach, datum errors introduced by inaccurate tropospheric correction methods are mitigated. To reduce the dependence of the troposphere delay on height, ECMWF reanalysis v5 (ERA5) data are employed to fit the TVPFM. Experimental analysis demonstrates that the troposphere exhibits distinct vertical variation characteristics, allowing for its segmentation into three layers. Consequently, a piecewise TVPFM is established. Observations obtained from the continuously operating reference stations network located in Yunnan, China, are utilized for validation. The selected stations exhibit a maximum height difference of approximately 2 km. The experimental results exhibit a notable enhancement in correction accuracy with the ITHC in comparison to conventional correction methodologies. Specifically, the ambiguity fixing rate demonstrates a noteworthy improvement of 13.3%, accompanied by a substantial increase in positioning accuracy by 51.4%.

Analysis of Different Height Correction Models for Tropospheric Delay Grid Products over the Yunnan Mountains

Accurate tropospheric delays are of great importance for both Global Navigation Satellite System (GNSS)-based positioning and precipitable water vapor monitoring. The gridded tropospheric delay products, including zenith hydrostatic delays (ZHD) and zenith wet delays (ZWD), are the most ideal method for accessing accurate tropospheric delays. The vertical adjustment method is critical for implementing the gridded tropospheric products. In this work, we consider the different models used for grid products and assess their performance over Yunnan mountains with complex topography. We summarize the main results as follows: (1) The products can provide accurate ZHD with mean biases of −2.6 mm and mean Standard Deviation (STD) of 1.5 mm while the ZWD results from grid products show a performance with biases of −0.4 mm and STD of 1.3 cm over the Yunnan area. (2) The Tv-based model shows a better performance than the T0-based model and IGPZWD in rugged areas with large height differences. The grid products can provide hourly ZHD with biases of 3 mm and wet delay with mean biases of within 2 cm and mean STD of below 3 cm in the Yunnan mountains, which exhibit a large height difference of around 1.5 km. (3) The radiosondes results confirm that the Tv-based model has an obvious advantage in calculating ZHD height corrections for differences within 2 km while the T0-model suffers from a loss in accuracy in the case of large height differences. If the site is located more than 1 km below the reference height, the IGPZWD model can provide a better ZWD with a mean bias of 1.5 cm and a mean STD of 1.7 cm. With vertical reduction models, the grid products can provide accurate ZHD and ZWD in real time, even if in complex area.

3D surgical planning method for lower jaw osteotomies applied to facial feminization surgery

Our proposed method uses a three-dimensional (3D) measurement approach that focuses mainly on the lower jaw from basal, lateral, and frontal views applied to the volumetric skull model derived from a computed tomography (CT) of the head. Likewise, we discuss the geometrical features and clinical considerations involved in the 3D biomodeling of the surgical osteotomy. The workflow that allowed this virtual planning to be developed was composed of medical imaging processing software, data extraction software from images, and statistical software that allows the creation and generation of curve-fitting (nonlinear regression) graphs from data. Thirty-two (32) anatomical points were positioned, sixteen (16) measurements were taken, and two-dimensional (2D) sketches in three views (frontal, lateral, and inferior) were generated to overlap in a 3D environment, which informed the cutting of the desired bone segments. Implementing a nonlinear regression curve-fitting on the contours of the original jaws allowed optimal planning of the osteotomy. Desired cutting shapes were extrapolated for the front view by third-order equations, while for the side and bottom views, log-normal distribution curves and second-order polynomial curves were used, respectively. The reduction in the mandibular volume was between 6.55 and 10.27 %, with two of the most important measurements related to vertical reduction in the lateral views and the difference to determine gonion reduction.

Vertical Scar Reduction Mammaplasty Using the Superomedial-Based Pedicle Technique in Gigantomastia.

Breast reduction surgery has witnessed significant advancements in recent years; however, it continues to pose challenges for both surgeons and patients when dealing with cases involving excessive breast volume and severe breast ptosis. This study aimed to assess the aesthetic outcomes and the impact on the quality of life, as measured by the BREAST-Q questionnaire, in patients with gigantomastia and severe breast ptosis who underwent reduction mammaplasty using the superomedial-based pedicle technique. We present a retrospective series comprising 84 patients who underwent reduction mammoplasty utilizing the superomedial pedicle technique. The surgical resections exceeded 1 kg per breast, with a mean resection weight of 1506.58 g (right breast) and 1500.32 g (left breast). The preoperative mean suprasternal notch to nipple distance measured 40.50 cm (right breast) and 40.38 cm (left breast). Postoperatively, the patients were followed up for a minimum of 6 months. Both preoperative and postoperative BREAST-Q surveys were administered to the participants, and scores were analyzed using descriptive statistics. Complications were observed in 3 patients (3.57%), characterized by partial loss of the areola, which resolved spontaneously over time. Additionally, 2 cases of hematoma and 2 instances of minor delayed wound healing were reported. All patients expressed satisfaction with their aesthetic outcomes, as they achieved a natural breast shape and minimal scarring, along with symptomatic relief. The superomedial pedicle reduction mammaplasty technique has demonstrated its ability to produce satisfactory aesthetic outcomes and long-term benefits in patients with excessively large breasts. Careful patient selection and postoperative management are vital for achieving optimal results. Further investigations involving larger sample sizes and longer follow-up periods are warranted to validate our findings. IV.

Impact of peri-implant keratinized mucosa width on the long-term reconstructive outcomes of peri-implantitis: A retrospective analysis with a follow-up up to 10 years.

To investigate the effect of mid-buccal peri-implant keratinized mucosa width (KMW) ≥2 mm or peri-implant KMW >0 mm and <2 mm on the long-term outcomes of peri-implantitis reconstructive treatment. Twenty-nine patients (40 implants; mean follow-up: 9.2 ± 1.4 years) with at least one implant affected by peri-implantitis and surgically treated through a reconstructive procedure followed by a submerged healing were included. Patients were categorized according to their initial KMW: Group 1 (KMW ≥2 mm) and Group 2 (KMW >0 mm and <2 mm). Peri-implant clinical and radiographic parameters and a dedicated composite outcome were assessed at different follow-up visits during supportive peri-implant therapy for up to 10 years. Regression analyses were utilized to identify possible risk/predictive indicators for probing pocket depth (PPD) change and treatment success at the latest follow-up. The mean PPD did not exhibit any statistical difference from the baseline to the latest follow-up between the groups at both patient and implant levels. Long-term treatment success was 46.6% (Group 1) and 42.6% (Group 2) at patient level, it was 42.8% (Group 1) and 33.3% (Group 2), respectively, at implant level (p > 0.05). Group 1 demonstrated significantly higher vertical defect depth reduction than Group 2 (p = 0.018). Presence of buccal bony wall and mean PPD at the baseline were found to be associated with mean PPD change, while KMW at 6 months following surgery was identified as the only significant indicator for treatment success (p < 0.05). Implants with KMW ≥2 mm did not present significantly better long-term clinical outcomes following reconstructive therapy than those exhibiting KMW >0 mm and <2 mm. However, KMW values at the end of healing phase following a submerged approach had a significant impact on long-term treatment success.

Vertical vibration control of structures with tuned liquid column dampers

Conventional tuned liquid column dampers (TLCDs) can only be used to suppress structural vibrations in horizontal directions. However, in reality, the vibration-induced motion of civil engineering structures normally consists of both vertical and horizontal components. In this study, a TLCD-based vibration control system, which is composed of a pair of inclined U-shaped containers, springs, dashpots, as well as supporting slopes, is proposed to control the vertical vibration of an engineering structure. The proposed control system (denoted as vertical TLCD) successfully extends the application of TLCD-type devices to vertical vibration reduction. First, the general configuration and operating principle of the proposed vertical TLCD are illustrated in detail. Second, the equations of motion are derived based on the Lagrange dynamic equations and further verified by two-way fluid–structure coupling numerical simulations using finite element method and finite volume method. Subsequently, the closed-form solution is derived for the optimized design of the vertical TLCD in the frequency domain. The dynamic characteristics of an optimized vertical TLCD-structure system are revealed. The effects of mass ratio, excitation amplitude and structural damping ratio on the optimization results are elaborated, respectively. Under the same optimized parameters, the vertical TLCD is found to be superior, compared to the vertical tuned mass damper (TMD). Finally, the effectiveness of the proposed system is demonstrated by applying it to the control of a bridge experiencing vertical vibrations under seismic loads. The findings of this study provide a comprehensive understanding of TLCD’s capabilities and identify its potential for vertical vibration control, which contributes to the development of more effective and versatile vibration mitigation strategies for a wide range of structures under different engineering scenarios.

Vertical gradient of needle ozone uptake within the canopy of Cryptomeria japonica

Leaf ozone uptake through the stomata is an important index for the ozone risk assessments on trees. Stomatal conductance (gs) and ozone concentration ([O3]), determinants of the leaf ozone uptake, are known to show vertical gradients within a tree canopy. However, less is known about the within-canopy vertical gradient of leaf ozone uptake. This study was aimed to elucidate how the vertical gradient of [O3] and gs affect needle ozone uptake within a canopy of mature Cryptomeria japonica trees in a suburban forest at Tokyo, Japan. For this purpose, a multilayer gas exchange model was applied to estimate the vertical gradient of needle gs and the accumulated ozone uptake during the study period (POD1, Phytotoxic Ozone Dose above a threshold of 1 nmol m−2 s−1). In addition, we also tested several scenarios of vertical gradient of [O3] within the canopy for sensitivity analysis. The POD1 was declined from the top to the bottom of the canopy. This tendency strongly depended on the vertical gradient of gs and was hardly affected by the changes in simulated vertical reductions of the [O3]. We further assessed the photosynthesis of sunlit needles (needles absorbing both direct and diffuse light) and shaded needles (needles only absorbing diffuse light). The photosynthesis of shaded needles in the upper half of the canopy made a great contribution to the entire canopy photosynthesis. In addition, given that their POD1 was lower than that of sunlit needles, ozone may affect sunlit and shaded needles differently. We concluded that these considerations should be incorporated into modeling of the calculation of ozone uptake for mature trees to make accurate predictions of the ozone effects on trees at the canopy scale.

Stress and Strain Characteristics in Flexible Pavement Using Three-Dimensional Nonlinear Finite Element Analysis

AbstractA new numerical simulation was developed to obtain various structural parameters by employing a nonlinear finite element method using ABAQUS: stress, strain, and the displacement response of five layers on the flexible pavement. The primary purpose of this study was to develop a new simulation that can accurately and effectively characterize stress and strain problems in flexible pavement. New constitutive model equations were developed based on Hooke’s law the three-dimensional model for stress and strain. 40 kN wheel load was used to represent a set of dual tires, assuming a uniformly distributed contact area between the tire-pavement surfaced using linear viscoelastic and nonlinear viscoelastic materials. Four tire-inflation pressures were used 380, 490, 630, and 700 kPa. Results indicated that each flexible pavement layer created with a nonlinear viscoelastic material exhibited a 40% vertical plastic strain reduction compared to linear viscoelastic materials after 7000 s and repeated for 30,000 cyclic loadings. The implication of this newly developed constitutive model was verified against published experimental data. Analyses were completed to simplify the results model results considering the effects of stress and strain on flexible pavement layers. The newly developed constitutive model for solving stress and strain characterization problems can predict the effects on flexible pavement layers and various types of observed flexible pavement failure.

The Derivation of Vertical Damping Reduction Factors for the Design and Analysis of Structures Using Acceleration, Velocity, and Displacement Spectra

Damping reduction factors (DRFs) play a vital role in the seismic design of structures. DRFs have been widely studied due to their primary importance to the lateral resistance of structures subjected to earthquakes. On the other hand, devastating earthquakes have occurred all over the world, and recently, the Kahramanmaraş earthquakes in Turkey revealed the import of the vertical component of earthquakes and their impact on structures and infrastructures. Considering the importance of this parameter, this paper aims to develop new damping reduction factor (DRF) equations for the acceleration (DRFa), velocity (DRFv), and displacement spectra (DRFd) of the vertical components of earthquakes. For this purpose, 775 real ground motion records were selected from the Pacific Earthquake Engineering Research (PEER) strong motion database, and the vertical elastic response spectra of selected records were computed according to linear dynamic analysis. Taking the 5%-damped vertical response spectra as the target, the vertical spectral damping reduction factors (DRFa, DRFv, and DRFd) were computed for 1%, 3%, 10%, 15%, 20%, 30%, and 40% damping ratios. The effect of the earthquake magnitude, distance, and soil types on the DRFs was investigated. The results indicated that magnitude, distance, and soil type had no particular effect on the trend in the DRFs. Based on the evaluations, extensive statistical analyses were carried out, and new prediction equations were developed according to the nonlinear regression method. The developed equations were then compared to those found in the literature and seismic design codes. The comparisons proved that the proposed DRFa, DRFd, and DRFv models are strongly compatible with real DRFs and show strong robustness compared to existing models.

Wind-driven post-bloom dispersion of Microcystis in a large shallow eutrophic lake: A case study in Lake Taihu

To clarify the wind-driven post-bloom dispersion range of Microcystis, which originally clustered on the water surface, an Individual-Based Model (IBM) of Microcystis movement considering the combined effects of wind and light was developed based on actual hydrodynamic data and Microcystis biomass. After calibrating the effects of hydrodynamics and light, 66 cases of short-term (within a week) post-bloom with satellite images from 2011 to 2017 were simulated. The results showed that there were three short-term post-bloom types: vertical reduction (VR), horizontal reduction (HR) and mixed reduction (MR). For VR type, the cyanobacterial bloom reduction rate was rapid (>160 km2/day), but the dispersion range of Microcystis was limited (<2 km/day), and a larger bloom area was likely to form in the original location when wind speed decreased. For HR type, the cyanobacterial bloom reduction rate was slow (<10 km2/day), but Microcystis exhibited a broad dispersion range (>4 km/day), often leading to smaller, thicker, and longer-lasting cyanobacterial blooms downwind, albeit with a lower probability of occurrence. The characteristics of MR lay between the two aforementioned types.

Maxillary Sinus Augmentation with Anorganic Bovine Bone Mineral of Different Particle Sizes: A Split-Mouth Study with Histomorphometric, Radiographic, and Clinical Analyses.

The aim of the present study was to compare the histomorphometrically evaluated new bone formation (NB), the radiographically measured graft stability, and the clinical implant outcome for maxillary sinus augmentation grafted with deproteinized bovine bone mineral (DBBM) with either small (Bio-Oss-S, Geistlich) or large (Bio-Oss-L, Geistlich) particles. Using a split-mouth study design, bilateral maxillary sinus augmentation was performed in 13 patients either with Bio-Oss-S particles (0.25 to 1 mm) or Bio-Oss-L particles (1 to 2 mm). After a healing period of 6 months, bone biopsies were axially retrieved in the molar region for histologic/histomorphometric analysis of NB, including subsequent staged implant placement. To determine graft stability, the maxillary sinus augmentation vertical graft heights were radiographically measured immediately after sinus augmentation, at implant placement, and at the 2- and 4-year post-augmentation follow-ups. In addition, the clinical implant-prosthodontic outcome (survival/ success/marginal bone loss) was assessed at 1 and 3 years post-loading. A total of 22 sinuses from 11 patients with split-mouth evaluation were ultimately available for data and statistical analysis. Histomorphometric analysis of the axially retrieved bone biopsies revealed the presence of NB (S: 25.5% ± 7.0% vs L: 23.6% ± 11.9%; P = .640), residual graft particles (S: 19.6% ± 9.2% vs L: 17.5% ± 6.3%; P = .365) as well as connective tissue (S: 54.9% ± 9.2% vs L: 58.9% ± 12.5%; P = .283), without significant differences between the use of small (Bio-Oss-S) and large (Bio-Oss-L) particles. However, there was significantly (P = .021) higher bone-to-graft contact (BGC) for the small-particle graft sites (27.9% ± 14.8%) compared to the large-particle graft sites (19.9% ± 12.9%), representing a significantly higher osteoconductivity. Both particle sizes showed significant (P < .01) vertical graft height reduction over time (4 years) of about 10%, with predominant graft reduction in the time period between sinus augmentation and implant placement compared to any follow-up periods after implant placement. At the 3-year post-loading implant evaluation, all implants and prostheses survived (100%), and the peri-implant marginal bone loss (S: 0.52 ± 0.19 mm; L: 0.48 ± 0.15 mm) as well as the peri-implant health conditions (S: 87.5%, L:81.2%) did not differ between implants inserted with the two different xenograft particles used. The use of small and large bovine xenograft particles for maxillary sinus augmentation provides for comparable bone formation, ensuring stable graft dimensions combined with high implant success and healthy peri-implant conditions. However, small particle size resulted in a higher BGC, providing for higher osteoconductivity than with the larger particle size.

Research on optimization of case adaptation and enhancement of knowledge application benefits for multi-decision class cases based on FASS-NRS and SAGA-FCM

PurposeTraditional case-adaptation methods have poor accuracy, low efficiency and limited applicability, which cannot meet the needs of knowledge users. To address the shortcomings of the existing research in the industry, this paper proposes a case-adaptation optimization algorithm to support the effective application of tacit knowledge resources.Design/methodology/approachThe attribute simplification algorithm based on the forward search strategy in the neighborhood decision information system is implemented to realize the vertical dimensionality reduction of the case base, and the fuzzy C-mean (FCM) clustering algorithm based on the simulated annealing genetic algorithm (SAGA) is implemented to compress the case base horizontally with multiple decision classes. Then, the subspace K-nearest neighbors (KNN) algorithm is used to induce the decision rules for the set of adapted cases to complete the optimization of the adaptation model.FindingsThe findings suggest the rapid enrichment of data, information and tacit knowledge in the field of practice has led to low efficiency and low utilization of knowledge dissemination, and this algorithm can effectively alleviate the problems of users falling into “knowledge disorientation” in the era of the knowledge economy.Practical implicationsThis study provides a model with case knowledge that meets users’ needs, thereby effectively improving the application of the tacit knowledge in the explicit case base and the problem-solving efficiency of knowledge users.Social implicationsThe adaptation model can serve as a stable and efficient prediction model to make predictions for the effects of the many logistics and e-commerce enterprises' plans.Originality/valueThis study designs a multi-decision class case-adaptation optimization study based on forward attribute selection strategy-neighborhood rough sets (FASS-NRS) and simulated annealing genetic algorithm-fuzzy C-means (SAGA-FCM) for tacit knowledgeable exogenous cases. By effectively organizing and adjusting tacit knowledge resources, knowledge service organizations can maintain their competitive advantages. The algorithm models established in this study develop theoretical directions for a multi-decision class case-adaptation optimization study of tacit knowledge.

Two characterizations of the dense rank

In this paper, we have considered the dense rank for assigning positions to alternatives in weak orders. If we arrange the alternatives in tiers (i.e., indifference classes), the dense rank assigns position 1 to all the alternatives in the top tier, 2 to all the alternatives in the second tier, and so on. We have proposed a formal framework to analyze the dense rank when compared to other well-known position operators, such as the standard, modified and fractional ranks. As the main results, we have provided two different axiomatic characterizations which determine the dense rank by considering position invariance conditions along horizontal extensions (duplication), as well as through vertical reductions and movements (truncation, and upward or downward independency).

Functional reconstruction of chronic acromioclavicular joint separation using a double suture technique combined with semitendinosus autograft.

We present the functional and clinical results of a combined surgical technique that functionally restores chronic Acromioclavicular Joint Instability (AJI). The method combines a double-looped suture fixation augmented with a semitendinosus autograft. Between 2017 and 2021, 15 patients were treated using the surgical technique. All patients suffered an Acromioclavicular Joint Separation that remained untreated for at least 6 (6-16) weeks after the initial injury. Four Ethibond sutures were passed below the coracoid process and through a 4.5 drill hole in the clavicle. The sutures provided adequate horizontal and vertical reduction and stabilization of the clavicle. A semitendinosus autograft was passed below the coracoid process and looped around the clavicle. The remaining graft limbs were used to reconstruct the acromioclavicular capsule. Patients were radiologically evaluated with bilateral anteroposterior (AP), Zanca, and Alexander views. The clinical evaluation was based on the Acromioclavicular Joint Instability Score and the Constant-Murley Score. The mean follow-up period was 31.2months (17-61). The mean last ACJIS and CMS scores were 96 (90-100) and 97.67 (87-100), respectively. Reduction of the clavicle was radiologically confirmed in all cases throughout the follow-up period. AC arthritis was reported in 1 case without associated clinical symptoms. No significant complications were reported, and all patients returned to the pre-injury activity level. The presented functional reconstruction of the AC joint disruption in chronic cases is an effective and secure method with low complication rates and good clinical results. This journal requires that authors assign a level of evidence to each article. For a full description of these Evidence-Based Medicine ratings, please refer to the Table of Contents or the online Instructions to Authors www.springer.com/00266 .

Coracoclavicular and acromioclavicular ligament reconstruction with a double-bundle semitendinosus autograft and cortical buttons for chronic acromioclavicular joint dislocations: clinical and imaging outcomes

BackgroundThere are few clinical and radiographic studies of coracoclavicular (CC) ligament reconstruction in chronic acromioclavicular (AC) joint dislocation. Additionally, reported AC joint reduction rates vary. HypothesisArthroscopically assisted double-bundle semitendinosus tendon autografts with CC and AC ligament reconstruction for AC joint reconstruction provide AC joint stability and improved function at the final visit. MethodsIn this retrospective study of prospectively collected data, 21 patients surgically treated for chronic AC joint dislocation (Rockwood III–V) were assessed clinically and radiographically preoperatively, and at day 1, 3 months, 12 months, and at a final visit (> 24 months) postoperatively. Clinical assessments included Constant and ASES scores. The CC vertical distance (CCD) on the affected and unaffected sides [CCD ratio (%)] on the anterosuperior view were measured. AC joint vertical reduction loss was defined as an increase in the CCD ratio of > 25%. Horizontal AC joint instability was evaluated on axillary views. Pearsons’ correlation coefficients were generated to examine the relationships among postoperative clinical scores, CCD ratio, interval from injury to surgery, and age at the time of surgery. ResultsTwenty-one shoulders in 21 patients (mean age, 40.0 years at the time of surgery; 16 men, 5 women) were evaluated with a mean 31.7-month follow-up period. The mean Constant scores, ASES scores, and CCD ratios significantly improved from preoperatively to the final visit [57.4 ± 10.1, 49.1 ± 12.1, 101.6 ± 64.1 preoperatively; 89.6 ± 5.3, 96.5 ± 4.2, 9.9 ± 34.5 at the final visit, respectively (P < 0.001 for all)]. Vertical AC and horizontal AC joint instability were observed in four shoulders (19.0%) and in one shoulder (4.8%), respectively. However, there was no significant correlation between the increase in CCD and clinical scores at the final visit (Constant score; r = 0.179, P = .438: ASES score; r = -0.260, P = .256) or the interval from injury to surgery (r = 0.099, P = .669) or age at the time of surgery (r = 0.019, P = .935). No clinical complications were associated with clinical symptoms. ConclusionsPatients who underwent the index procedure achieved significant improvement in shoulder function without complications related clinical symptom after a mean follow-up interval of 31.7 months. In contrast, the rates of total ACJ instability in the vertical and horizontal planes were unsatisfactory but compatible with those in previous studies.

Impact of Variable Parameters of Expansion Joints and Bearing Supports on the Vehicle-Induced Vibration of Curved Girder Bridges

To study how varying the parameters of expansion joints and bearing supports (E-B parameters) affects the dynamic response of a coupled vehicle–bridge system for curved girder bridges, a dynamic response analysis method for the coupled vehicle–joint (bearing)–bridge system, which takes into account centrifugal forces, was proposed and verified. Subsequently, taking a continuous curved box girder bridge as the prototype, the influence of the E-B parameters on the vehicle-induced dynamic response of the curved girder bridge was explored. The results showed that the dynamic amplification factor (DAF) of the middle beam of the expansion joint (DAF-EJ) and the main girder of the curved bridge (DAF-MG) were both significantly influenced by the E-B parameters. When there were height differences between the middle beam and side beam in the EJ, the DAF-EJ obviously varied, and the DAF-MG increased. When the EJ was damaged, the impact effect of the vehicle on the bearing support increased. The DAF-EJ and DAF-MG both increased with the decrease of the vertical support stiffness of the bearing support. The DAF-EJ was greatly affected by the single-support void at the near-slit end of the lane. The DAF-MGs at the beam end, the 1/4 point and 1/2 point of the first span, and the 1/2 point of the second span, were significantly affected by the single-support void near the measuring point. Compared with the single-support void, the DAF-EJ and DAF-MG more significantly increased under the double-support void. Variation in the height difference of the EJ had a more significant effect on the DAF-EJ and DAF-MG at the beam end, while a vertical stiffness reduction in the bearing support had a more significant effect on the DAF-MG.

Effect of single and dual voids on vertical capacity of large-diameter monopiles in marine clay

This study utilizes the finite element limit analysis (FELA) method to numerically investigate the effect of single and dual voids on the vertical bearing capacity of nearshore large-diameter monopiles in marine clay. After validating the numerical model, numerous numerical analyses in predicting the behavior of the pile-void system were conducted under different geometric parameters of pile and void, different pile-void distances, and different undrained shear strengths. These numerical results can be expressed in the form of design charts for vertical capacity reduction coefficients, which can facilitate a quick and straightforward assessment of pile capacity considering single and dual voids by multiplying the capacity without voids by respective coefficients. In addition, the numerical results can further give the contours of the plastic multiplier of the pile-void system which can be used to graphically conclude several representative failure modes. In short, this study intuitively illustrates the void effect on the pile vertical bearing capacity (including failure mode) and shows the significant differences between the cases with single and dual voids.