Distal Research Articles

Pediatric reference values for myocardial contraction fraction and global function index of the left ventricle: A cardiovascular magnetic resonance study

BackgroundCardiovascular magnetic resonance (CMR) derived global function index (GFI) and myocardial contraction fraction (MCF) were identified as useful imaging markers to assess left ventricular (LV) cardiac performance and can provide prognostic information for several cardiac diseases. As pediatric reference values are lacking, the aim of this retrospective study was to establish these values. Methods154 CMR examinations of healthy children and adolescents (4–18 years) were included. LV end-diastolic, end-systolic and stroke volumes, ejection fraction (LVEF) and myocardial mass were measured using short axis stacks. Results were used to calculate LVGFI and LVMCF. Statistically, the Lambda-Mu-Sigma (LMS)-method was applied to create percentile curves and tables. ResultsThe mean age (standard deviation) of the subjects was 13.8 (2.8) years, 102 were male (66%). Mean LVGFI was 46.3 (6.0)% and mean LVMCF was 110.6 (19.9) %. Both, LVGFI and LVMCF decreased significantly with age (LVGFI: r = −0.30, p < 0.001; LVMCF: −0.30, p < 0.001). There was no statistical difference between girls and boys (p all >0.05). Strong correlations between LVGFI and LVMCF (r = 0.78, p < 0.001) as well as between LVGFI and LVEF (r = 0.80, p < 0.001) were documented whereas the correlation of LVMCF and LVEF was weaker (r = 0.32, p < 0.001). Univariable and multivariable regression analysis demonstrated that LVGFI was strongly associated with age whereas LVMCF was associated with weight. Percentile curves and tables were created accordingly. ConclusionWe provide pediatric CMR reference values for the new cardiac functional markers LVGFI and LVMCF. These may improve the interpretation of clinical CMR studies and can be used for future research studies.

Dimension of normal anterior cruciate ligament on MRI in our population.

Objective: The present study will help us in establishing local statistics in our population. Study Design: Descriptive study. Setting: Department of Orthopedic Surgery at Khyber Teaching Hospital in Peshawar. Period: June 2023 to December 2023. Methods: Seventy MRI of knee were collected. Knee MR images sagittal and coronal plane (T2-Weighted Images) were reviewed by radiologist and only knees with an intact cruciate ligament were included in the study. All the measurement (length and width) were made with electronic caliper. Results: Regarding radiological length of ACL on sagittal view on MRI, the minimum length was 28mm and maximum was 46mm and mean length was 34mm and standard deviation of 4.49, Regarding width of ACL on sagittal view it was found that the minimum length was 8mm and maximum was 16mm and its mean length was 10.4mm with standard deviation of 2.02. While the width of ACL on coronal plane was such that the minimum length was 6mm maximum was 16mm its mean was 11.34 and standard deviation of 2.48. By applying one sample T-Test and compare with Kowen parameter the p value was 0.00 for both length and width showing statistically highly significant. Conclusion: In conclusion in our population ACL is shorter and thicker then westerns population. Further studies should be done arthroscopically and on cadaveric to establish our local statistics of anthropometric measurements of anterior cruciate ligament.

An initial investigation into the use of virtual reality (VR) glasses on self-reported pain perception during mammography

ObjectivePain is one of the causes of refraining from mammography. This study aimed to investigate the use of virtual reality (VR) glasses for management of pain during mammography. MethodsFifty subjects who were referred to the radiology unit for mammography screening were invited to participate in the study. The study was approved by the hospital's ethics committee and participants provided written and oral informed consent. Craniocaudal (CC) and mediolateral oblique (MLO) views of the right breast were first acquired, followed by left CC and MLO mammographic views with the VR glasses on. After the examination, participants completed a questionnaire including a validated visual analog scale (VAS) scoring system to analyze pain scores. Data were analyzed using Spearman's rho and the Kruskal-Wallis test, as well as the Bland–Altman analysis to examine discrepancy. ResultsThe association of the right breast pain score with the parameters of age, breast density, previous mammography, family history of breast cancer, educational attainment, and employment status was examined using a correlation test. All the parameters showed no significant correlation with the right breast pain score except age (p: 0.016, correlation coefficient: −.340). Apart from that this study demonstrated no significant correlation between the perceived pain experienced during mammography and the utilization of VR technology. ConclusionThe findings indicate an inverse correlation between participant's age and pain perception during mammography examinations. Moreover, the utilization of Virtual Reality (VR) did not demonstrate efficacy in reducing pain perception.

An Earth-sized Planet on the Verge of Tidal Disruption

TOI-6255 b (GJ 4256) is an Earth-sized planet (1.079 ± 0.065 R ⊕) with an orbital period of only 5.7 hr. With the newly commissioned Keck Planet Finder and CARMENES spectrographs, we determine the planet’s mass to be 1.44 ± 0.14 M ⊕. The planet is just outside the Roche limit, with P orb/P Roche = 1.13 ± 0.10. The strong tidal force likely deforms the planet into a triaxial ellipsoid with a long axis that is ∼10% longer than the short axis. Assuming a reduced stellar tidal quality factor Q⋆′≈107 , we predict that tidal orbital decay will cause TOI-6255 to reach the Roche limit in roughly 400 Myr. Such tidal disruptions may produce the possible signatures of planet engulfment that have been seen on stars with anomalously high refractory elemental abundances compared to their conatal binary companions. TOI-6255 b is also a favorable target for searching for star–planet magnetic interactions, which might cause interior melting and hasten orbital decay. TOI-6255 b is a top target (with an Emission Spectroscopy Metric of about 24) for phase-curve observations with the James Webb Space Telescope.

Risk factors for malalignment after intramedullary nail treatment of distal tibia fractures with associated fibula fractures

PurposeMalalignment of distal tibia fractures can lead to malunion/nonunion or alter the limb mechanical axis which may cause arthritis. Proposed methods to decrease malalignment include fibular fixation or multiplanar interlocking screws, however these remain controversial. This study aimed to identify factors associated with malalignment in distal tibial fractures with associated fibular shaft fractures.MethodsA retrospective review was performed of distal tibia fractures with associated fibular shaft fractures treated with intramedullary nailing at two level one trauma centers between 2015 and 2019. Cases involving malalignment (> 5° of deviation from anatomic axis on either coronal/sagittal axis) on final follow-up (minimum three months postoperatively) were compared to those without malalignment with regard to demographics, fracture characteristics, intraoperative characteristics, and complications.ResultsThe rate of malalignment was 13%. On multivariate analysis, multiplanar distal interlocking screw fixation (odds ratio [OR], 0.18; 95% confidence interval [CI] 0.03–0.92) was associated with a decreased rate of final malalignment, while nail diameter > 10 mm was associated with a higher rate (OR, 4.05; 95% CI 1.25–13.11). Fibular fixation was not associated with malalignment.ConclusionMultiplanar distal interlocking screws may protect against malalignment. Fibula fixation does not appear associated with a decreased rate of malalignment in distal tibia fractures treated with intramedullary nails.Level of EvidenceIII.

Improved Acromiohumeral Distance Independently Predicts Better Outcomes After Arthroscopic Superior Capsular Reconstruction Graft Tears

PurposeTo identify independent factors responsible for the poor outcomes after a graft tear after arthroscopic superior capsular reconstruction (ASCR). MethodsPatients who underwent ASCR for massive rotator cuff tears between January 2013 and July 2021were reviewed. Based on the achievement of the minimal clinically important differences for clinical outcome measures at the final follow up, patients were divided into the good outcome (GO) and poor outcome (PO) groups. The minimal clinically important differences were calculated as the values equal to one‐half of the standard deviation of the changes in outcome scores between the preoperative baseline and the latest follow‐up. Pre- and final follow-up variables included demographics, American Shoulder and Elbow Surgeons (ASES) score, Constant score, visual analog scale (VAS) score, range of motion, Preoperative and postoperative 1-year radiological variables were analyzed using MRIs, including anteroposterior (AP) and mediolateral (ML) tear sizes, subscapularis tear, acromiohumeral distance (AHD), and degree of fatty degeneration. Logistic regression analysis was performed to identify the significant predictors of poor outcomes. ResultsA total of 33 patients who underwent ASCR presented with graft tears, which were confirmed by postoperative 1-year magnetic resonance imaging (MRI), and had a minimum follow-up duration of 2 years after surgery were enrolled. The GO group demonstrated significantly greater improvements in functional outcomes compared with the PO group (ASES: 83.5 ± 11.8 vs. 64.0 ± 20.4, P = 0.004; Constant: 67.6 ± 5.7 vs. 57.1 ± 9.8, P <0.001; and VAS: 0.9 ± 1.2 vs. 2.4 ± 2.0, P = 0.026). The postoperative 1-year AHD showed significant improvement in the GO group (3.1 ± 1.2 vs. 6.1 ± 1.4, P <0.001) but no change in the PO group (3.4 ± 1.3 vs. 4.2 ± 0.9, P = 0.074) postoperatively. Multivariate logistic regression analysis indicated that a decreased postoperative 1-year AHD (OR, 0.145; P = 0.019) was associated with a poor outcome after a graft tear. ConclusionA narrow postoperative 1-year AHD was identified as the most importantindependent risk factor indicating poor clinical outcomes after a graft tear post-ASCR, which was related to a larger tear and loss of integrity between the grafts and infraspinatus at 1 year postoperatively. Level of evidenceLevel IV.

Ultrasonographic Assessment of the Thymus Among Neonates Admitted in a Special Newborn Care Unit of a Medical College Hospital in Eastern India.

The thymus is essential for the maturation of T-lymphocytes, crucial for adaptive immunity. In neonates, thymic development is influenced by factors such as gestational age, birth weight, birth length, etc. Ultrasonography offers a non-invasive method to assess thymic size and morphology. However, there is limited research on thymic ultrasonography among neonates in Eastern India. This study aimed to investigate the ultra-sonographic characteristics of the thymus in neonates admitted to a Special Neonatal Care Unit (SNCU) in Eastern India and its correlation with certain clinical and anthropometric variables. Conducted from May to July 2024, this cross-sectional observational study involved 80 neonates admitted to the SNCU at the College of Medicine & Sagore Dutta Hospital. Thymic ultrasonography, using an Esaote MylabX7 ultrasound machine with a 3-11 MHz linear probe (Esaote, Genoa, Italy), measured thymic length, width, anteroposterior (AP) dimension, sagittal area, and thymic index. Clinical data, including gestational age, birth weight, birth length, and antibiotics received, were collected from medical records. Pearson's correlation coefficient and linear regression analysis were used to examine correlations and predictors of thymic dimensions. The cohort consisted of 45 boys (56%) and 35 girls (44%). The average birth weight was 2,626 grams for boys and 2,639 grams for girls. The median gestation period was 38 weeksfor both groups. Thymic measurements did not significantly differ by gender. Correlation analysis revealed significant relationships between thymic dimensions and neonatal anthropometric measurements. Birth weight showed a strong positive correlation with thymic length (r = 0.486) and width (r = 0.233). Linear regression identified birth weight as a significant predictor of the thymic index (p < 0.001), explaining 21.2% of the variance. This study provides insights into the factors associated with thymic size in neonates, highlighting the critical role of birth weight in thymic development. Future research should explore additional variables influencing thymic size and consider larger sample sizes to enhance model explanatory power and its potential role in immunity.

The different subtypes of cam morphology as defined by statistical shape modeling and their relationship with the development of hip osteoarthritis: A nationwide prospective cohort study (CHECK) with 10 years follow-up

ObjectiveTo determine if subtypes of cam morphology on anteroposterior (AP) radiographs exist using statistical shape modelling (SSM), and to assess their association with incident radiographic hip osteoarthritis (RHOA) within 10 years. DesignThe nationwide prospective Cohort Hip and Cohort Knee (CHECK) study included 1,002 participants aged 45-65 years with 10-year follow-up. Subtypes of cam morphology were defined as SSM-based shape variations of femoral head-neck junction that are associated with baseline cam morphology (alpha angle ≥60°). The association between each subtype in hips free of osteoarthritis at baseline (Kellgren & Lawrence (KL) grade <2) and incident RHOA (KL grade≥2, or a total hip replacement) was estimated using logistic regression at 10-year follow-up and stratified by sex. ResultsIn sex-combined group, but also for males and females separately, cam morphology subtypes were captured in modes 1, 3, 4, and 5 with odds ratios (ORs) ranging from 0.39(0.27-0.58) to 2.25(1.64-3.10). For sex-combined group, only mode 3, a flattened head-neck junction, was associated with incident RHOA (OR:1.14, 1.02-1.27). Males’ modes 1 and 3 and females’ modes 3 and 4 were associated with RHOA. Notably, the female mode 4, a slightly flattened neck but with subtle curvature, was significantly protective for RHOA (OR:0.88, 0.80-0.98). ConclusionsWe identified four distinct morphological subtypes of cam morphology defined by alpha angle. Only some subtypes were found acting as risk factors for RHOA at 10-year follow-up, which differed between males and females. This highlights the need to study cam morphology beyond the alpha angle alone.

A taxon-restricted duplicate of Iroquois3 is required for patterning the spider waist.

The chelicerate body plan is distinguished from other arthropod groups by its division of segments into 2 tagmata: the anterior prosoma ("cephalothorax") and the posterior opisthosoma ("abdomen"). Little is understood about the genetic mechanisms that establish the prosomal-opisthosomal (PO) boundary. To discover these mechanisms, we created high-quality genomic resources for the large-bodied spider Aphonopelma hentzi. We sequenced specific territories along the antero-posterior axis of developing embryos and applied differential gene expression analyses to identify putative regulators of regional identity. After bioinformatic screening for candidate genes that were consistently highly expressed in only 1 tagma (either the prosoma or the opisthosoma), we validated the function of highly ranked candidates in the tractable spider model Parasteatoda tepidariorum. Here, we show that an arthropod homolog of the Iroquois complex of homeobox genes is required for proper formation of the boundary between arachnid tagmata. The function of this homolog had not been previously characterized, because it was lost in the common ancestor of Pancrustacea, precluding its investigation in well-studied insect model organisms. Knockdown of the spider copy of this gene, which we designate as waist-less, in P. tepidariorum resulted in embryos with defects in the PO boundary, incurring discontinuous spider germ bands. We show that waist-less is required for proper specification of the segments that span the prosoma-opisthosoma boundary, which in adult spiders corresponds to the narrowed pedicel. Our results demonstrate the requirement of an ancient, taxon-restricted paralog for the establishment of the tagmatic boundary that defines Chelicerata.

Performance testing of a novel short axis photomultiplier tube for the HUNT project

Photomultiplier tubes (PMTs) with large-area cathodes are increasingly being used in cosmic-ray experiments to enhance detection efficiency. The optical modules (OMs) of the High-Energy Underwater Neutrino Telescope (HUNT) have employed a brand new N6205 20-inch microchannel plate photomultiplier tube (MCP-PMT) developed by the North Night Vision Science & Technology (Nanjing) Research Institute Co. Ltd. (NNVT). In order to make the 20-inch PMT fit into the 23-inch diameter pressure-resistant glass sphere, NNVT improved the internal structure of PMT and shortened the height of PMT by more than 10 cm. The first batch of these PMTs has been delivered for preliminary research work. This paper describes a specific PMT testing platform built for the first batch of 15 MCP-PMTs, and some performance parameters of PMT, such as peak-to-valley ratio, TTS and nonliniearity, are measured. The measurement results show that the new PMT still has good performance and can meet the requirements of HUNT project.

The Cambrian Odaraia alata and the colonization of nektonic suspension-feeding niches by early mandibulates.

The diversity of cephalic morphologies in mandibulates (myriapods and pancrustaceans) was key to their evolutionary success. A group of Cambrian bivalved arthropods called hymenocarines exhibit diagnostic mandibulate traits that illustrate this diversity, but many forms are still poorly known. These include the odaraiids, typified by Odaraia alata from the Burgess Shale (Wuliuan), characterized by its unique tubular carapace and rudder-like tail fan, and one of the largest Cambrian euarthropods at nearly 20 cm in length. Unfortunately, odaraiid cephalic anatomy has been largely unknown, limiting evolutionary scenarios and putting their mandibulate affinities into question. Here, we reinvestigate Odaraia based on new specimens from the Burgess Shale and describe exquisitely preserved mandibles with teeth and adjacent structures: a hypostome, maxillae and potential paragnaths. These structures can be homologized with those of Cambrian fuxianhuiids and extant mandibulates, and suggest that the ancestral mandibulate head could have had a limbless segment but retained its plasticity, allowing for limb re-expression within Pancrustacea. Furthermore, we show the presence of limbs with spinose endites which created a suspension-feeding structure. This discovery provides morphological evidence for suspension feeding among large Cambrian euarthropods and evinces the increasing exploitation of planktonic resources in Cambrian pelagic food webs.

Determination of the best point of entry of percutaneous insertion of sacroiliac screws depending on patient positioning for surgery: A cadaveric study.

The standard starting point for percutaneous sacroiliac screw insertion was initially determined at the intersection of the line posterior to the anterior superior iliac spine and the line continuing the anatomical axis of the femur. The technique was pioneered in patients lying prone in surgery, although it has been used with patients in the supine position. The optimal starting point for patients in both prone and supine positions remains uncertain. This cadaveric study aimed to determine the best entry point for the percutaneous insertion of sacroiliac screws depending on the patient's positioning for surgery. Kirschner wires (K-wires) were percutaneously inserted into the sacral body of 8th human cadavers. In addition to the so-called standard sacroiliac screw entry point (point A), points located consecutively 1 cm (point B) and 2 cm (point C) cranially from the point along the line, prolonging the femoral axis were also studied. The K-wires were inserted into the studied entry points on the right side in a supine position and on the left side of the same cadaver in a prone position. The placement of the K-wires was assessed using radiographic imaging and cadaver dissection. An analysis of the K-wire placement in the supine position revealed incorrect positioning of 100% of the K-wires inserted at entry point A and 87% at entry point B. All the K-wires inserted in the supine position at entry point C were correctly placed. All K-wires inserted in the prone position were correctly positioned. All 3 studied entry points enabled the correct placement of orthopedic implants for prone position surgery. The best entry point for surgery performed in the supine position was located 2 cm cranially from the standard entry point, along the line prolonging the femoral axis.

Analysis of maxillary teeth and soft tissue profiles among Tibetan and Han Chinese females with facial symmetry for orthodontic treatment planning.

The evaluation of maxillary teeth and soft tissue profiles is a critical component of orthodontic diagnosis and treatment planning. This study aimed to evaluate the correlation between the sagittal position of maxillary anterior teeth and facial profile esthetics among Tibetan and Han Chinese adult females for optimizing orthodontic diagnosis and treatment planning. A total of 100 Tibetan Chinese and 100 Han Chinese adult females with good facial symmetry were recruited. The smiling facial profile images with the maxillary central incisors and forehead in full view were taken based totally on the same standard. The photo measurement and head position were adjusted using the picture-enhancing software. The reference traces associated with forehead inclinations were utilized to assess the anteroposterior (AP) positions of the maxillary central incisors. The results showed that a round forehead was the dominant forehead shape for Tibetan (93%) and Han (55%) Chinese females. In Tibetan females, 85% of the maxillary central incisors were found to be located between the forehead's anterior limit line (the Gall line) and the goal anterior limit line (the Fall line), with 15% located posterior to the Fall line. This distribution manifested a strong association with incisor position and forehead inclination (R2 = 0.742). In Han females, 83% of the maxillary central incisors were located between the Fall line and the Gall line, with 12% posterior to the Fall line and 5% anterior to the Gall line. The positions of the maxillary central incisors exhibited a strong relationship with forehead inclination (R2 = 0.827). The maxillary central incisors were close to the aesthetic line in both ethnic groups, while forehead inclinations were correlated with AP maxillary incisor position. These findings demonstrated that there was a close relationship between the incisor position of Tibetan and Han females with facial symmetry and the forehead FFA factor, indicating a reference in oral hard and soft tissues for optimizing orthodontic diagnosis and treatment planning in terms of facial contour.

Measurements of the Interventricular Septum and Mitral Leaflet Length in Hypertrophic Cardiomyopathy Patients Who Underwent Surgical Myectomy: A Prospective Comparative Multimodality Imaging Study

Transesophageal echocardiography (TEE) plays an important role for real-time procedural guidance during surgical myectomy (SM) for hypertrophic obstructive cardiomyopathy (HOCM). We aimed to compare a) IVS thickness using two (2D) and three-dimensional (3D) intraoperative TEE and pre-operative cardiac magnetic resonance (CMR) and b) mitral valve (MV) leaflet length using 2D, 3D TEE, automatic quantification of mitral valve (AMVQ) and pre-operative CMR. We prospectively studied 50 HOCM patients (age 59 ±12, 44% men) undergoing SM during 2018-2019. Maximal basal, mid, and distal anteroseptum (AS) and inferoseptum (IS) were measured by multiplanar 3D reconstruction on TEE and by short axis imaging on pre-operative CMR, and classified as mild (≤18mm), moderate (18-25mm) or severe (≥ 25 mm) groups, based on AS and IS thickness on CMR. MV leaflet lengths were evaluated by pre-operative CMR and intra-procedural 2D TEE, zoom 3D TEE and AMVQ (EchoPAC, General Electric, Wi). There was a moderate correlation between AS and IS thickness on 3D TEE and CMR (R2=0.46, p<0.01 and R2=0.41, p<0.01 respectively), with 3D TEE showing an average overestimation of 3.8 and 4.7 mm vs. CMR. 3D TEE over-estimated 14 (56%) patients with mild thickness as moderate, and 5 (22%) patients with moderate thickness as severe. Assuming 3D TEE as the gold standard, the closest correlation for anterior mitral leaflet length was with CMR (average overestimation by CMR of 0.5 mm [root mean square deviation or RMSE% 17]), intermediate correlation with 2D TEE (average deviation of 0.6 mm [RMSE%:21]) and no correlation with AMVQ (average deviation of 0.7mm [RMSE% 24]). In conclusion, 3D TEE overestimates IVS thickness vs. CMR in HOCM patients undergoing SM, with greater discrepancy in those with thinner IVS. There are significant differences in MV lengths measured using different imaging techniques.

Assessment Accuracy of 2D vs. 3D Imaging for Custom-Made Acetabular Implants in Revision Hip Arthroplasty.

Revision total hip arthroplasty (rTHA) presents significant challenges, particularly in patients with severe acetabular bone defects. Traditional treatment options often fall short, leading to the emergence of custom-made 3D-printed acetabular implants. Accurate assessment of implant positioning is crucial for ensuring optimal postoperative outcomes and for providing feedback to the surgical team. This single-center, retrospective cohort study evaluates the accuracy of standard 2D radiographs versus 3D CT scans in assessing the positioning of these implants, aiming to determine if 2D imaging could serve as a viable alternative for the postoperative evaluation. We analyzed the implant positions of seven rTHA patients with severe acetabular defects (Paprosky ≥ Type IIIA) using an alignment technique that integrates postoperative 2D radiographs with preoperative CT plans. Two independent investigators, one inexperienced and one experienced, measured the positioning accuracy with both imaging modalities. Measurements included translational shifts from the preoperatively templated implant position in the craniocaudal (CC), lateromedial (LM), and ventrodorsal (VD) directions, as well as rotational differences in anteversion (AV) and inclination (INCL). The study demonstrated that 2D radiographs, when aligned with preoperative CT data, could accurately assess implant positions with precision nearly comparable to that of 3D CT scans. Observed deviations were 1.4 mm and 2.7 mm in CC and LM directions, respectively, and 3.6° in AV and 0.7° in INCL using 2D imaging, all within clinically acceptable ranges. For 3D CT assessments, mean interobserver variability was up to 0.9 mm for translational shifts and 1.4° for rotation, while for 2D alignment, observer differences were 1.4 mm and 3.2° for translation and rotation, respectively. Comparative analysis of mean results from both investigators, across all dimensions (CC, LM, AV, and INCL) for 2D and 3D matching, showed no significant differences. In conclusion, conventional anteroposterior 2D radiographs of the pelvis can sufficiently determine the positioning of custom-made acetabular implants in rTHA. This suggests that 2D radiography is a viable alternative to 3D CT scans, potentially enhancing the implementation and quality control of advanced implant technologies.

Correction of Aero-Optical Effect with Blow–Suction Control for Hypersonic Vehicles

High-speed turbulence induces significant aero-optical effects that severely disrupt the functionality of imaging systems of hypersonic vehicles. In this study, the aero-optical correction of various jet cooling modes is investigated using a Terminal High Altitude Area Defense (THAAD)-like seeker model and the imaging impact of high-speed flow field and flow control on the optical window is analyzed by the Delayed Detached Eddy Simulation (DDES) method. The findings reveal that a jet mode parallel to the window exhibits better cooling effectiveness compared to a perpendicular jet mode along the body axis; however, it introduces additional wavefront distortion, leading to degraded imaging quality. Although micro-vortex generators (MVGs) can reduce density fluctuations near the window from a refractive index perspective, they do not effectively mitigate wavefront distortion or improve window cooling efficiency. Finally, incorporating suction control, a comprehensive flow control solution, significantly improves the flow field structure near the window, resulting in a more uniform temperature distribution and reduced wavefront distortion. Applying this flow control method results in a 14.7% reduction in wavefront distortion at 3 Ma and an approximately 20% maximum value reduction at 5 Ma. This study proposes a novel and comprehensive flow control method to effectively mitigate the aero-optical effect in hypersonic flows, providing a new avenue for subsequent researchers in this field.

Center of Pressure Measurement Accuracy via Insoles with a Reduced Pressure Sensor Number during Gaits.

The objective was to compare simplified pressure insoles integrating different sensor numbers and to identify a promising range of sensor numbers for accurate center of pressure (CoP) measurement. Twelve participants wore a 99-sensor Pedar-X insole (100 Hz) during walking, jogging, and running. Eight simplified layouts were simulated, integrating 3-17 sensors. Concordance correlation coefficients (CCC) and root mean square errors (RMSE) between the original and simplified layouts were calculated for time-series mediolateral (ML) and anteroposterior (AP) CoP. Differences between layouts and between gait types were assessed via ANOVA and Friedman test. Concordance between the original and simplified layouts varied across layouts and gaits (CCC: 0.43-0.98; χ(7)2 ≥ 34.94, p < 0.001). RMSEML and RMSEAP [mm], respectively, were smaller in jogging (5 ± 2, 15 ± 9) than in walking (8 ± 2, 22 ± 4) and running (7 ± 4, 20 ± 7) (ηp2: 0.70-0.83, p < 0.05). Only layouts with 11+ sensors achieved CCC ≥ 0.80 in all tests across gaits. The 13-sensor layout achieved CCC ≥ 0.95 with 95% confidence, representing the most promising compromise between sensor number and CoP accuracy. Future research may refine sensor placement, suggesting the use of 11-13 sensors. For coaches, therapists, and applied sports scientists, caution is recommended when using insoles with nine or fewer sensors. Consulting task-specific validation results for the intended products is advisable.

Factors Related to Cholesteatoma Formation in External Auditory Canal Osteomas and Treatment Algorithm.

Objectives: Osteomas in the external auditory canal (EAC) can lead to stenosis, and impair epithelium migration and self-cleaning capability, thereby trapping keratinized epithelium and triggering the development of cholesteatoma. Our study aims to identify the risk of cholesteatoma development in patients with osteoma and proposes a stepwise approach to managing patients with EAC osteoma. Methods: The maximum diameter of the osteoma was measured in axial and coronal views on high-resolution computed tomography (HRCT). We calculated the relative obstruction ratio caused by the osteoma in the axial and coronal views. Prior to surgery, otoscopy was employed to identify pedicle formation. The patients were categorized into 2 groups based on the presence of cholesteatoma. Results: We identified 43 patients diagnosed with EAC osteoma. A total of 9 (20.9%) patients with EAC osteomas developed cholesteatoma and the other 34 (79.1%) did not. The maximum diameter of osteomas with and without cholesteatoma was 12.67 ± 4.09 and 7.67 ± 3.27 mm, respectively (P < .001). In the group without cholesteatoma, 21 osteomas had pedicles while the other 13 did not. In the cholesteatoma group, 2 osteomas had pedicles and 7 did not (P = .037). No difference was observed in the relative obstruction ratio between these 2 groups. Conclusions: Our findings indicate that larger osteomas are more likely to develop cholesteatoma, while the formation of a pedicle may reduce the occurrence of cholesteatoma. In symptomatic patients, preoperative evaluation, including HRCT and otoscopy, is vital for assessing the extent of the osteoma and the potential coexistence of cholesteatoma. These factors are critical for preoperative consultations and surgical planning.

Electromyographic Analysis of Large Muscle Activity in Progressive Collapsing Foot Deformity.

There are various deformities described in the spectrum of Progressive Collapsing Foot Deformity (PCFD) which not only have adverse effects on the foot but also on the entire lower limb. Early lower limb muscular fatigue and pain during exertion is the most common complaint of patients with PCFD. Surface electromyography (sEMG) provides an accurate assessment of muscle activity. In this study, we aim to compare the activities of quadriceps, hamstrings, and gastrosoleus muscle groups of adult patients with PCFD with normal lower limbs and correlate the radiological parameters and functional effects of PCFD with the activities. Thirty patients with bilateral PCFD and 30 controls underwent weight-bearing anteroposterior (AP), lateral, and hindfoot alignment radiographs of the foot. Radiographic parameters of PCFD were assessed. Surface electromyography was used to assess the quadriceps, hamstrings, and gastrosoleus activities, and this was compared between the 2 groups and correlated with radiological measurements of PCFD. Tegner activity questionnaire was used to assess the functional effects of collapsed arch. Electrical activities of all muscle groups were significantly higher in cases than controls. Meary's angle and hindfoot moment arm had significant correlations with hamstring activity (P = .013) and gastrosoleus activity (P = .027), respectively. Tegner scores of cases were significantly lower than those of controls (P = .041). The PCFD causes an increase in activity of large muscles of the affected lower limb which act on joints other than those in the foot. This finding may be due to several compensatory mechanisms that counteract the deforming forces. This may be a cause for the frequent complaint, early fatigue, and hence functional impairment. However, most radiological parameters did not correlate with muscle activities and larger study size may be required for further association. Diagnostic: Level 3.

Callus formation after total hip arthroplasty using a short tapered-wedge stem.

The incidence of periprosthetic fractures after total hip arthroplasty using a short tapered-wedge stem is high. Callus formation preceding this fracture, which indicates postoperative stress fracture around the stem, has been reported. However, previous studies on postoperative callus are limited. Hence, the current study aimed to evaluate the prevalence and risk factors of postoperative callus after total hip arthroplasty with a short tapered-wedge stem. This retrospective study included 127 patients who underwent total hip arthroplasty using a cementless short tapered-wedge stem. The depth of stem insertion was measured as the distance from the lateral corner of the stem to the most medial point of the lesser trochanter along the body axis. Postoperative callus was defined as a bridging callus on the lateral femoral cortex at the distal end of the porous coating of the stem. Plain radiography was performed before surgery and immediately and at 1, 3, and 6months after surgery to assess postoperative callus. Univariate and multivariate logistic regression analyses were performed to identify the risk factors for PC. In total, 60 (47.2%) of 127 patients presented with postoperative callus. Multivariate logistic regression analysis with postoperative callus as the dependent variable revealed that the stem depth at 1month after total hip arthroplasty (odds ratio, 1.14; 95% confidence interval, 1.04-1.24, p = 0.002) was a significant and independent risk factor of postoperative callus. Deep insertion of a short tapered-wedge stem is a risk factor for postoperative callus.