Distal Research Articles

Genome-wide identification and expression profiling of the Wnt gene family in three abalone species.

The Wnt gene family plays pivotal roles in a variety of biological processes including cell proliferation and differentiation, apoptosis, and embryonic development. Identifying the Wnt signaling pathway in abalone could provide a basis for elucidating growth and development mechanisms and improving quality. To identify the number, protein physicochemical properties, gene structure, phylogenetic analysis, and expression profiles of the Wnt gene family in abalone. A comprehensive genome-wide analysis was performed to identify the Wnt gene family in the genomes of three abalone species (Haliotis discus hannai, H. rubra, and H. rufescens). Ten single-copy Wnt genes were identified in each abalone species, suggesting that the number of Wnt genes was relatively conserved in Haliotis. Eight Wnt gene subfamilies, including Wnt1, Wnt4, Wnt5, Wnt6, Wnt7, Wnt10, Wnt16, and WntA, are present in all three species. Each abalone species contains two species-specific subfamilies (Wnt9 and Wnt11 in H. discus hannai, Wnt2 and Wnt11 in H. rubra, and Wnt2 and Wnt9 in H. rufescens), reflecting polymorphisms of the Wnt genes in Haliotis. Interestingly, gastropods are characterised by the loss of Wnt8, suggesting a potential evolutionary specificity in gastropods. As expected, Wnt3 is absent in all protostomes, including the abalone. In addition, spatio-temporal expression profiling revealed differential expression levels of the Wnt genes at different developmental stages and in different tissues of H. discus hannai. HdWnt5 and HdWntA might participate in several processes during larval development stages, including germ layer formation and body axis elongation. HdWnt5 may be involved in eye and tentacle development. HdWnt10 may be related to muscle development, and HdWnt6 may be involved in shell formation in abalone. To our knowledge, the results of this study, which is the first genome-wide investigation of the Wnt gene family in abalone, lay the groundwork for future research on the evolution and function of the Wnt gene family in Gastropoda.

Radiographic features and subtypes of congenital thumb duplication type C3 according to Wu et al. and their potential implications for surgical management: new classification and preliminary results

BackgroundWu et al. introduced a modified radiographic system that allows classification of all forms of CTD with excellent interobserver and intraobserver reliability. No study to date has evaluated the radiographic characteristics of Wu et al. type C3 CTD with osseous attachment at the level of the metacarpal.ObjectiveThis study aimed to evaluate the radiographic features of type C3 CTD according to the system of Wu et al., to describe the different anatomical subtypes of the duplication, and to propose a categorization approach to distinguish diverse surgical strategies based on the radiographic anatomy of this specific subtype of duplication.MethodsWe performed a retrospective analysis of 215 patients (221 thumbs) diagnosed with Wu et al. type C3 CTD at our Institution between 2015 and 2021. We evaluated all CTDs by examining the alignment of the interphalangeal (IP) and metacarpophalangeal (MP) joints and by assessing the presence of abnormal hypertrophic epiphysis of the primary thumb on posteroanterior (PA) radiographs. The proposed classification system has four types: Type I with good alignment of both MP and IP joints, Type II with ulnar deviation of the MP joint, Type III with radial deviation in the MP joint and Type IV with abnormal hypertrophic epiphysis of the distal phalanx of the main thumb with ulnar deviation of the IP joint with or without ulnar deviation of the MP joint.ResultsThere were 140 male and 75 female patients with CTD (221 thumbs). There were 65 left, 144 right and 6 bilateral forms. The right-to-left, male-to-female and unilateral-to-bilateral ratios were 2.2:1, 1.9:1 and 35.8:1 respectively. The mean age at surgery was 22.3 ± 11.8 months (range, 8–80). The proposed classification system allowed the classification of all CTDs (n = 221). Specifically, 53 fingers were classified as Type I (24%), 136 as Type II (61.5%), 21 as Type III (9.5%), and 11 as Type IV (5%).ConclusionThe proposed system is based on radiographic pathoanatomy and complements that of Wu et al. by identifying four distinct subtypes of deformity. It has the potential to improve inter-professional communication and guide surgery in patients with Wu et al. type C3 CTD. However, our results are preliminary and further research is needed to validate them.Level of evidenceIII.

Formation of the interatrial septum: Insights obtained from cardiac computed tomographic angiography.

We previously described a septal variant termed left atrial septal pouch (LASP). Present in a third of hearts, it results from incomplete fusion of the septum primum (SP) and septum secundum (SS). We assessed the prevalence of LASP using 64-section multidetector computed tomography and further characterized the different variants. Among 864 scans, 770 were of sufficient quality for assessment (428 male, aged 59.2 ± 11.7 years). They were classified on the basis of the degrees of fusion of the SP and SS into a completely fused septum (CFS), patent foramen ovale (PFO), or LASP. The lengths of the SS, SP, and overlapping SP, the maximal length of the foramen ovale (FO) floor, and the atrial dimensions were compared. A PFO was seen in 181 patients (23.5%), a LASP in 242 (31.4%), and a CFS in 339 (44.0%). There were significant differences in the length of the SS (PFO-13.6 ± 4.3 mm, LASP-17.6 ± 4.8 mm, CFS-14.3 ± 7.7 mm, p < 0.001). Hearts with LASPs had a longer overlapping SP than those with PFOs (PFO-6.3 ± 4.5 mm, LASP-13.1 ± 5.2 mm, p < 0.001). The maximal lengths of the FO floor showed differences in short axis (SAX) view (PFO-21.7 ± 4.5 mm, LASP-15.3 ± 4.3 mm, CFS-16.3 ± 4.3 mm, p < 0.001). Hearts with PFO and LASP showed similar SP lengths (27.3 ± 6.6 mm vs. 26.4 ± 6.6 mm, p = 0.10). There was a positive linear correlation between the length of the SS and the overlapping SP (R2 = 0.28, p < 0.001) with a weaker negative correlation between the SS length and maximal length of the FO floor (R2 = 0.02, p < 0.001). The groups showed similar atrial dimensions and volumes. Present in a third of patients, hearts with LASP have longer SS and overlapping SP.

Progressive First Metatarsal Shortening Is Observed Following Dermal Allograft Interpositional Arthroplasty in Hallux Rigidus: Short Report.

The main goal of this study was to evaluate postoperative changes in the length of the first metatarsal (M1) and the proximal phalanx of the hallux (P1) after acellular dermal allograft interpositional arthroplasty (ADA-IPA). We hypothesized that there would be a shortening of the first ray at the first metatarsal, the proximal phalanx, or both. In this retrospective study, we assessed patients who underwent ADA-IPA between 2019 and 2022. On standing anteroposterior (AP) foot radiographs, we measured first metatarsal (M1), second metatarsal (M2), proximal phalanx (P1), and the entire hallux (HX) lengths. M1/M2 and P1/HX ratios were calculated. The first metatarsophalangeal joint space was calculated. All measurements were recorded preoperatively, at 6 weeks postoperatively, and at final follow-up. The pilot study included 11 patients. At final follow-up, we found shortening of M1 and P1 in comparison to the preoperative length, as evidenced by lower M1/M2 (82.6 ± 2.3 vs 75.4 ± 5.1; P = .001) and P1/HX ratios (53.4 ± 2.3 vs 48.9 ± 7.9; P = .001). Follow-up length was negatively correlated with M1/M2 (r = -0.76, P = .003). ADA-IPA might be associated with shortening of both first metatarsal and proximal phalanx, with the former showing progressive shortening.

Las placas intrapélvicas suprapectíneas interfieren con la evaluación postoperatoria de la calidad de reducción por radiografía simple. Hallazgos sobre una serie retrospectiva de fracturas de acetábulo

IntroductionIntrapelvic suprapectineal plates play an important role in acetabular fracture fixation. However, the shape of these implants may interfere with the quality of reduction evaluations using plain X-rays. We sought to evaluate this artifact and its relationship with CT findings. Materials and methodsIn a retrospective, single-center series of 22 acetabular fractures, postoperative AP, alar and obturator X-ray views and CT images were evaluated by three independent observers. Cohen's kappa was used to examine interrater reliability. ResultsSuprapectineal plates interfered with the evaluation of the weight-bearing surface in 75.3%, and with all three oblique views in 43.9% of cases. The central segment was most consistently interfered with, corresponding to the area where the greatest malreduction was in 46.9% coronal and 42.4% of sagittal CT views. ConclusionsSince the quality of reduction has prognostic value and is a necessary guide for the surgical team, that CT may be considered for the postoperative examination of the most challenging acetabular fracture cases.

Simulation of osteotomy in total knee arthroplasty with femoral extra-articular deformity assisted by artificial intelligence: a study based on three-dimensional models

BackgroundThe impact of extra-articular deformities (EADs) on lower limb alignment and collateral ligament integrity during total knee arthroplasty (TKA) poses significant challenges, increasing surgical complexity. Our study aims to evaluate the influence of EADs on mechanical axis alignment and the risk of collateral ligament injury during TKA using an AI-assisted surgical planning system, with the goal of minimizing ligament damage through precise and scientific planning.MethodsA healthy volunteer underwent CT and MRI scans of the lower limbs. The scan images were imported into Mimics 20.0 software, and the reconstructed models were spatially aligned using 3-maticResearch 11.0 software. Using Unigraphics NX9.0 software, 50 three-dimensional models of femoral lateral joint deformities with varying positions and angles were created. Finally, TKA was simulated using the AI JOINT preoperative planning system.ResultsThe larger the deformity angle and the closer it is to the knee joint, the more pronounced the deviation of the mechanical axis. During MA-aligned osteotomy, nine types of deformities can damage the collateral ligaments. After adjusting the varus/valgus of the prosthesis within a safe range of 3° and leaving a residual 3° varus/valgus in the lower limb alignment, only the 25° varus and 25° valgus deformities located at 90% of the femoral anatomical axis remain uncorrected.ConclusionFor patients with osteoarthritis and concurrent EAD undergoing TKA, using reconstructed 3D models of the collateral ligaments for preoperative planning helps visually assess collateral ligament damage, providing a practical solution. Minimizing intra-articular osteotomies within a safe range and allowing some residual alignment deviation can reduce the risk of collateral ligament injury.

The temporal specificity of BOLD fMRI is systematically related to anatomical and vascular features of the human brain.

The ability to detect fast responses with functional MRI depends on the speed of hemodynamic responses to neural activity, because hemodynamic responses act as a temporal low-pass filter which blurs rapid changes. However, the shape and timing of hemodynamic responses are highly variable across the brain and across stimuli. This heterogeneity of responses implies that the temporal specificity of fMRI signals, or the ability of fMRI to preserve fast information, could also vary substantially across the cortex. In this work we investigated how local differences in hemodynamic response timing affect the temporal specificity of fMRI. We used ultra-high field (7T) fMRI at high spatiotemporal resolution, studying the primary visual cortex (V1) as a model area for investigation. We used visual stimuli oscillating at slow and fast frequencies to probe the temporal specificity of individual voxels. As expected, we identified substantial variability in temporal specificity, with some voxels preserving their responses to fast neural activity more effectively than others. We investigated which voxels had the highest temporal specificity, and tested whether voxel timing was related to anatomical and vascular features. We found that low temporal specificity is only weakly explained by the presence of large veins or cerebral cortical depth. Notably, however, temporal specificity depended strongly on a voxel's position along the anterior-posterior anatomical axis of V1, with voxels within the calcarine sulcus being capable of preserving close to 25% of their amplitude as the frequency of stimulation increased from 0.05Hz to 0.20Hz, and voxels nearest to the occipital pole preserving less than 18%. These results indicate that detection biases in high-resolution fMRI will depend on the anatomical and vascular features of the area being imaged, and that these biases will differ depending on the timing of the underlying neuronal activity. While we attribute this variance primarily to hemodynamic effects, neuronal nonlinearities may also influence response timing. Importantly, this spatial heterogeneity of temporal specificity suggests that it could be exploited to achieve higher specificity in some locations, and that tailored data analysis strategies may help improve the detection and interpretation of fast fMRI responses.

Accuracy and efficiency of 2D/3D single-vertebra spine navigation registration method based on dual-view feature fusion

Objective: To investigate the accuracy and efficiency of spine 2D/3D preoperative CT and intraoperative X-ray registration through a framework for spine 2D/3D single-vertebra navigation registration based on the fusion of dual-position image features. Methods: The preoperative CT and intraoperative anteroposterior (AP) and lateral (LAT) X-ray images of 140 lumbar spine patients who visited Huashan Hospital Affiliated to Fudan University from January 2020 to December 2023 were selected. In order to achieve rapid and high-precision single vertebra registration in clinical orthopedic surgery, a designed transformation parameter feature extraction module combined with a lightweight module of channel and spatial attention (CBAM) was used to accurately extract the local single vertebra image transformation information. Subsequently, the fusion regression module was used to complement the features of the anterior posterior (AP) and lateral (LAT) images to improve the accuracy of the registration parameter regression. Two 1×1 convolutions were used to reduce the parameter calculation amount, improve computational efficiency, and accelerate intraoperative registration time. Finally, the regression module outputed the final transformation parameters. Comparative experiments were conducted using traditional iterative methods (Opt-MI, Opt-NCC, Opt-C2F) and existing deep learning methods convolutional neural network (CNN) as control group. The registration accuracy (mRPD), registration time, and registration success rate were compared among the iterative methods. Results: Through experiments on real CT data, the image-guided registration accuracy of the proposed method was verified. The method achieved a registration accuracy of (0.81±0.41) mm in the mRPD metric, a rotational angle error of 0.57°±0.24°, and a translation error of (0.41±0.21) mm. Through experimental comparisons on mainstream models, the selected DenseNet alignment accuracy was significantly better than ResNet as well as VGG (both P<0.05). Compared to existing deep learning methods [mRPD: (2.97±0.99) mm, rotational angle error: 2.64°±0.54°, translation error: (2.15±0.41) mm, registration time: (0.03±0.05) seconds], the proposed method significantly improved registration accuracy (all P<0.05). The registration success rate reached 97%, with an average single registration time of only (0.04±0.02) seconds. Compared to traditional iterative methods [mRPD: (0.78±0.26) mm, rotational angle error: 0.84°±0.57°, translation error: (1.05±0.28) mm, registration time: (35.5±10.5) seconds], registration efficiency of the proposed method was significantly improved (all P<0.05). The dual-position study also compensated for the limitations in the single-view perspective, and significantly outperforms both the front and side single-view perspectives in terms of positional transformation parameter errors (both P<0.05). Conclusion: Compared to existing methods, the proposed CT and X-ray registration method significantly reduces registration time while maintaining high registration accuracy, achieving efficient and precise single vertebra registration.

Sex Disparity in the Canal-to-Body Ratio of the Cervical Spine Indicating the Prevalence of Cervical Myelopathy: A Cross-Sectional Study

Abstract Background A narrow spinal canal and large vertebral body have been thought to be risk factors for cervical myelopathy. It is generally known that males are more likely to develop cervical myelopathy than females. Thus, sex is also a factor that contributes to myelopathy. The anteroposterior (AP) diameter of the cervical spinal canal is well-established as a primary factor of myelopathy. Objective To investigate the sex discrepancy in the canal-to-body ratio of the cervical spine on magnetic resonance imaging (MRI). Materials and Methods This cross-sectional study included 59 males and 59 females, all aged between 20 and 40 years. Morphological parameters, including height, AP diameter of the vertebral body, and AP diameter of the spinal canal, were measured on sagittal T2-weighted MRI cervical spine images for each participant. The canal-to-body ratio, obtained by dividing the spinal canal's AP diameter by the vertebral body's AP diameter, served as a key metric. The average canal-to-body ratio values compared between male and female groups at each spinal level (C3–C7) elucidate potential gender-related differences. Results The height and the AP diameter of the vertebral body were larger in males than in females throughout C3–C7. There was a statistically significant difference between males and females. The AP diameter of the spinal canal was similar for both genders, with no statistically significant difference between them. The mean canal-to-body ratio was significantly larger in females than in males, with a statistically significant difference between males and females at each spinal level. Conclusion Females had a larger canal-to-body ratio, and men had a significantly lower one. The canal-to-body ratio method was thought to be superior to the absolute value of the AP diameter of the spinal canal for the diagnosis of canal stenosis.

8138 Pituitary Stalk Interruption Syndrome (PSIS) in a patient with Isolated Hypogonadotropic Hypogonadism

Abstract Disclosure: A. Thomson: None. R. Osman: None. Pituitary Stalk Interruption Syndrome in a Patient with Isolated Hypogonadotropic Hypogonadism Pituitary Stalk Interruption syndrome (PSIS) is a rare cause of hypopituitarism, characterized by a radiologic constellation of thin or interrupted pituitary stalk, hypoplasia, or aplasia of the anterior lobe and with the presence of an ectopic posterior pituitary (EPP). It is most commonly associated with isolated growth hormone deficiency (IGHD) and is often diagnosed in childhood. We present one case of a patient with isolated hypogonadotropic hypogonadism in adulthood, subsequently found to have an PSIS on MRI. A 45 year old male patient presented to our clinic with hypogonadism. He gradually started developing decreasing libido, fatigue, and loss of erections. He had normal puberty and childhood growth, and has fathered one child. He denied history of anosmia or visual symptoms. Subsequent hormonal testing showed: morning Total Testosterone: 145 ng/dl (normal 264-916 ng/dl), Free testosterone 1.5 pg/ml (normal 6.8-21.5 pg/ml), LH 1.1 mIU/ml (normal 1.7-8.6 mIU/ml) and FSH of 3.6 mIU/ml (normal 1.5-12.4 mIU/ml). Prolactin was minimally elevated at 21 ng/ml (normal 4.0 - 15.2 ng/ml). Thyroid, IGF-1, cortisol, and ferritin levels were within normal limits. Repeat levels showed similar findings. He denied ever taking any form of exogenous testosterone. His pituitary MRI revealed a small volume of anterior pituitary tissue, measuring 0.2cm x 0.7cm x 0.7cm, without discrete pituitary adenoma, a hypoplastic midline stalk measuring 1.3 mm in AP diameter (nl 2-3 mm), with a T1 hyperintense nodularity measuring 0.6cm x 0.4cm along the posterior aspect of the sella turcica consistent with EPP. No additional structural abnormality or any mass lesions were identified. He was subsequently started on replacement testosterone therapy and his symptoms resolved. PSIS usually presents in childhood with IGHD. Patients may have other pituitary hormone deficiencies and congenital central nervous system defects, although panhypopituitarism is rare. There have been reports in children with delayed puberty and isolated hypogonadotropic hypogonadism who have been found to have PSIS. Only one othercase of an adult female patient exhibiting hypogonadotropic hypogonadism as the only manifestation of PSIS has been documented in the literature. Our case highlights the potential for an adult male to present later in life with hypogonadotropic hypogonadism as a manifestation of PSIS. The marginally elevated prolactin level may be due to lack of inhibition of hypothalamic dopamine on lactotroph cells within the pituitary caused by the EPP, although it is doubtful that this has clinical significance. This is a rare presentation of PSIS, clinicians should be mindful ofthis radiological constellation and the potential for isolated hypogonadotropic hypogonadism presenting unusually in the adulthood. Presentation: 6/3/2024

7404 Evaluation Of Cortisol Reserve And Adrenal Imaging In Patients With Graves’ Disease Before And Six Months After Treatment

Abstract Disclosure: P. Sharma: None. S. Mir: None. S. Mohd Patto: None. A.H. Bhat: None. B. Dar: None. M. Bhat: None. Introduction: There is scarcity of data regarding the effect of thyrotoxicosis on cortisol metabolism and adrenal gland size. An increase in cortisol metabolism can deplete the functional reserve of adrenal cortex and lead to adrenocortical insufficiency even when there is no pre-existing Addison's disease. In developing countries patients with Graves’ disease present in advanced states of thyrotoxicosis. Besides they are also exposed to a variety of environmental stresses such as recurrent febrile illnesses, salt, and water loss due to manual labour in hot and humid climates etc., which can precipitate an adrenal crisis in the presence of compromised adrenal reserve. So present study was undertaken to assess cortisol reserve and adrenal gland size in patients with treatment naive Graves' disease. Objectives- The present study, was undertaken to assess cortisol reserve and adrenal imaging in patients with treatment naive Graves' disease. Specific information in this regard would help alert physicians dealing with clinical thyrotoxicosis in developing countries of tropics to the possibility of co-existing adrenal decompensation and adopt appropriate life saving measures promptly. Material &amp; Methods: We examined 38 treatment-naive Graves' Disease patients at GMC, SSH, Srinagar, Kashmir, INDIA. Basal cortisol and cortisol response to ACTH were measured before and after six months of treatment, alongside adrenal CT imaging. Results: In hyperthyroid state, Graves' patients exhibited significantly lower basal cortisol compared to euthyroid and healthy controls (306 vs. 410 vs. 421 nmol/l, p &amp;lt; 0.05). 23.6% patients had subnormal cortisol response to ACTH(250ug). Those with T3 ≥ 400 ng/dl had lower cortisol response (560±133 nmol/l) and delta cortisol response than T3 &amp;lt; 400 ng/dl (724 ± 294 nmol/l, 213+/-73 vs. 428+/-265 nmol/l). After achieving euthyroid state, cortisol levels improved significantly (410±213 nmol/l vs. 306 ± 103 nmol/l, p &amp;lt; 0.05). Adrenal CT scans in 34 patients was done out of which 19 showed statistically significant increases in gland thickness, width, and AP diameter compared to controls (p &amp;lt; 0.01, p &amp;lt; 0.05. Repeat CT in 26 patients demonstrated resolution of hyperplasia (p &amp;lt; 0.05). Conclusion: Treatment-naive Graves' disease patients have compromised adrenocortical reserve and adrenal gland enlargement. Adrenal changes are reversible after achieving euthyroid state. These findings support steroid supplementation in impending thyrotoxic crisis and highlight a unique feature of reversible adrenal gland enlargement in this context. Keywords: Graves’ Disease, Adrenal hyperplasia, Cortisol reserve. Presentation: 6/3/2024

Introduction of oblique plane waves through a forcing source term in Euler equations

The propagation of shock waves generated by a transonic flow at the tip of a propeller blade is numerically calculated in order to determine the pressure footprint on an aircraft fuselage. An academic case is first proposed to validate the methodology. An incoming signal is built up as oblique harmonic plane waves. The signal is introduced in the computational domain using a Gaussian volume forcing term in the conservation of mass and energy equations. The Euler equations are solved in two dimensions using finite-difference schemes with low dispersion and dissipation. Selective filtering has also been integrated in the algorithm to remove grid-to-grid oscillations. The numerical solution is compared to an analytical solution based on the tailored Green function. An illustration for a realistic open rotor is then considered. The pressure signal near the blade tip, determined from a preliminary RANS simulation, is introduced using a volume source in a solver of the Euler equations.

The Buds of Oscarella lobularis (Porifera, Homoscleromorpha): A New Convenient Model for Sponge Cell and Evolutionary Developmental Biology.

The comparative study of the four non-bilaterian phyla (Cnidaria, Placozoa, Ctenophora, and Porifera) provides insights into the origin of bilaterian traits. To complete our knowledge of the cell biology and development of these animals, additional non-bilaterian models are needed. Given the developmental, histological, ecological, and genomic differences between the four sponge classes (Demospongiae, Calcarea, Homoscleromorpha, and Hexactinellida), we have been developing the Oscarella lobularis (Porifera, class Homoscleromorpha) model over the past 15 years. Here, we report a new step forward by inducing, producing, and maintaining in vitro thousands of clonal buds that now make possible various downstream applications. This study provides a full description of bud morphology, physiology, cells and tissues, from their formation to their development into juveniles, using adapted cell staining protocols. In addition, we show that buds have outstanding capabilities of regeneration after being injured and of re-epithelization after complete cell dissociation. Altogether, Oscarella buds constitute a relevant all-in-one sponge model to access a large set of biological processes, including somatic morphogenesis, epithelial morphogenesis, cell fate, body axes formation, nutrition, contraction, ciliary beating, and respiration.

Effects of Parallax and Distortion in Total Ankle Arthroplasty.

Surgeons rely on intraoperative fluoroscopy to assist in placement of implant components during total ankle arthroplasty (TAA). Parallax alters the direction of an object when viewed from two different points, resulting in image distortion. The purpose of this study was to evaluate parallax/distortion in intraoperative fluoroscopic images during TAA. A retrospective review of all TAAs performed by two surgeons (R.W.M. and B.S.) from August 2019 to April 2023 were reviewed. Intraoperative fluoroscopic anteroposterior (AP) ankle views were evaluated for any obvious parallax image distortion. Cases with obvious parallax distortion were included for angular evaluation of AP intraoperative fluoroscopic and first postoperative plain films. The tibia was marked at 2-centimeter intervals to create zones from the proximal stem of the implant. The anatomical axis of the tibia (AAT) was drawn at the mid-diaphysis. The anatomic lateral distal tibial angle (aLDTA) and anatomic axis deviation (AAD) were measured for each zone. A total of 22 TAAs were performed during the study period. Four cases were excluded due to inadequate imaging, leaving a total of 18 TAAs for review. We found 6 of 18 (33.3%) cases had obvious parallax distortion. We found the average aLDTA was 90.9° (84°-101°). At the most proximal tibial zone, the average aLDTA was 94° (91°-101°). We found the average AAD was 4.7 (0.5-17.2) mm. The AAD ranged from 0.5 to 17.2 mm lateral to 0.8 to 8.2 mm medial. Postoperative plain film radiographs displayed a normal aLDTA and an AAT centered within the ankle joint. Parallax can distort the appearance of the tibia on fluoroscopic images. Deviation from the normal aLDTA and anatomical axis should be anticipated. Surgeons should be aware of the potential impact of parallax and ways to mitigate these effects.

Posture-dependent modulation of marmoset cortical motor maps detected via rapid multichannel epidural stimulation

Recent neuroimaging and electrophysiological studies have suggested substantial short-term plasticity in the topographic maps of the primary motor cortex (M1). However, previous methods lack the temporal resolution to detect rapid modulation of these maps, particularly in naturalistic conditions. To address this limitation, we previously developed a rapid stimulation mapping procedure with implanted cortical surface electrodes. In this study, employing our previously established procedure, we examined rapid topographical changes in forelimb M1 motor maps in three awake male marmoset monkeys. The results revealed that although the hotspot (the location in M1 that elicited a forelimb muscle twitch with the lowest stimulus intensity) remained constant across postures, the stimulus intensity required to elicit the forelimb muscle twitch in the perihotspot region and the size of motor representations were posture-dependent. Hindlimb posture was particularly effective in inducing these modulations. The angle of the body axis relative to the gravitational vertical line did not alter the motor maps. These results provide a proof of concept that a rapid stimulation mapping system with chronically implanted cortical electrodes can capture the dynamic regulation of forelimb motor maps in natural conditions. Moreover, they suggest that posture is a crucial variable to be controlled in future studies of motor control and cortical plasticity. Further exploration is warranted into the neural mechanisms regulating forelimb muscle representations in M1 by the hindlimb sensorimotor state.

The influence of miscentering on radiation dose during computed tomography head examinations and the role of localiser orientation: A phantom study

IntroductionComputed Tomography (CT) chest, abdomen and pelvis research demonstrates a relationship between vertical phantom positioning and radiation dose. Moving the phantom closer or further from the x-ray source results in magnification or minimisation of the localiser. As automatic tube current modulation (ATCM) algorithms use localisers to estimate patient size and calculate required tube current, magnification or minimisation results in the incorrect provision of radiation dose. Radiation dose changes also depend on localiser orientation, changes with anteroposterior (AP) and posteroanterior (PA) localisers demonstrating an inverse relationship. However, within CT head literature often attributes radiation dose changes on impaired function of the bow-tie filter instead. The current study investigated the role of miscentering on ATCM function within CT head, paying particular attention to localiser orientation. MethodsHead scanning was performed with an anthropomorphic phantom at the isocentre, alongside ten vertically miscentered positions. This was performed three times, with an AP, PA and lateral localiser. CT dose index values at each miscentered level were compared across conditions. ResultsVertical miscentering altered radiation dose in both AP and PA conditions, radiation dose linearly increasing (up to 17.05%) when positioning the phantom closer to the x-ray source and decreasing when positioning away (up to −13.13%). Changes across AP and PA conditions demonstrated an inverse relationship. Radiation dose was unaffected in the lateral condition. ConclusionsMiscentering during CT head alters ATCM function due to magnification/minimisation of the localiser image, causing ATCM algorithms to misinterpret patient size and miscalculate required tube current. Implications for practiceRadiographers should be accurate when centering for CT head, avoiding any potential radiation dose changes. Further research into vertical miscentering and image quality during CT head is recommended.

Computational assessment dose distribution of the antero-posterior and postero-anterior in Boron Neutron Capture Therapy for colorectal cancer

Abstract Colorectal is part of the gastrointestinal system that anatomically and physiologically, is excretory and extends throughout the abdominal region. In BNCT (Boron Neutron Capture Therapy) treatment for colorectal cancer, special projections are needed to ensure the dose is distributed effectively in cancer cells. Computational evaluation was carried out using PHITS 3.30 version, to determine the number of doses for organs at risk in the Antero-Posterior (AP) projection compared to the Postero-Anterior (PA) projection in this case, if the cancer cells are located in different parts, there are rectum and colon (transverse). BNCT treatment planning was designed using a female abdomen phantom voxel with the patient position Left Lateral Decubitus. Based on the simulation and evaluation results, it’s confirmed that isoeffective dose and irradiation time examined in the rectum is significantly reduced in the postero-anterior position so that postero-anterior and antero-posterior calculation results are 0.74 Gy and 20.61 Gy. However, if the cancer cells are in the transverse colon, antero-posterior projection is more effective for cases of colon cancer in the transverse colon of 0.71 Gy, and the postero-anterior projection with a dose of 29.15 Gy.

Short humeral stem in total shoulder arthroplasty does not jeopardize primary implant stability

BackgroundThe trend of the modern humeral components in total shoulder arthroplasty (TSA) is towards shorter and shorter humeral stems. However, the question remains whether short uncemented stems can provide the same implant stability as long stems. This study aimed to evaluate and compare the torsional primary stability, and the pull-out extraction force of both a long and a short version of the same stem. Materials and MethodsTen humeral components (five long-stem and five short-stem) were press-fitted into ten synthetic composite humeri. A torsional load was applied to generate the most critical loading condition. The specimens were loaded with 100 cycles between 2 Nm and 10 Nm, at 1 Hz. A 3D Digital Image Correlation system was used to measure the relative displacement between the prosthesis and the host bone during the test. After completing the torsional test, the pull-out force was measured. Differences between the long and short-stem on the biomechanical parameters (permanent migrations, inducible micromotion, and extraction force) were tested with the non-parametric Mann-Whitney test (p<0.05). ResultsThe main rotational inducible micromotion was around the craniocaudal axis. No significant differences were found between the rotational permanent migrations of the long- and short-stem around the craniocaudal (p=0.421), anteroposterior (p=0.841), and mediolateral axes (p=0.452). No significant differences were found between the rotational inducible micromotions of the long- and short-stem around the craniocaudal (p=0.222), anteroposterior (p=0.420), and mediolateral axes (p=0.655). No significant differences were found between the permanent translations of the long- and short-stem the along craniocaudal (p=0.341), anteroposterior (p=0.420), and mediolateral (p=0.429) directions. No significant differences were found between the translations of the long- and short-stem in terms of inducible translation in the craniocaudal (p=0.547), anteroposterior (p=0.999), and mediolateral axis (p=0.285). Similar extraction force (p=0.35) was found. Discussion and ConclusionNo statistically significant difference was found between the long-stem and short-stem implants. These results show that short uncemented stems can provide adequate primary mechanical stability. As the long-stem version of this stem is already clinically used, the present findings suggest that the short-version can be reasonably expected to deliver similar outcomes in terms of implant stability.

Structural Analysis for Qazzaz Metamorphic Core Complex, Northwestern Arabian Shield, Saudi Arabia

AbstractIdentifying deformational mechanisms and associated structures at various scales, ranging from regional‐scale structures to microscopic fabric, is crucial for the assessment of tectonic development. Thirty‐three samples were taken from the Qazzaz metamorphic core complex to estimate the finite strain for felsic and mafic minerals. These samples included gneisses rocks, monzogranite, and metavolcano–sedimentary rocks for both the Thalbah and Bayda groups. Using the Rf/j and Fry methods, the axial ratios (XZ) range about 2.20 to 7.10 and 1.90 to 9.10, respectively. For various rock units, the strain measurements show moderate to highly deformation. Most of the observed samples show shallow WNW dipping along a N to WNW trend of finite strain (X). The short axes (Z) based to be subvertical foliation related with a subhorizontal foliation. The results demonstrate that contacts generated at semi‐brittle to ductile deformation and that the strain of magnitude has the same value for different lithologic units. It concluded that nappe generation in orogens results from pure shear deformation.

Ultrasound Shear Wave Elastography of the Arch-Supporting Structures in Symptomatic Flatfoot: A Pilot Study.

The posterior tibial tendon (PTT), deltoid ligament, and spring ligament are often torn or attenuated in patients with progressive collapsing foot deformity. The goal of this pilot study was to measure the ultrasound shear wave velocity (SWV) of these arch-supporting structures in feet with varying degrees of deformity to improve our understanding of their role in the progression of deformity. Two observers measured the SWV of the supramalleolar and inframalleolar PTT in long and short axes, in the tibiospring portion of the deltoid ligament, and in the superomedial band of the spring ligament in 8 neutrally aligned feet, 5 asymptomatic flatfeet, and 7 symptomatic flatfeet. Each measurement was repeated 3 times both with and without an applied eversion stress. Average SWV was lower at all locations in the symptomatic flatfeet compared with normal feet, but these differences were statistically significant only for the inframalleolar PTT and the spring ligament. Externally applied stress led to an increase in the SWV of the ligaments but a paradoxical decrease in the SWV in the supramalleolar PTT. The SWV of the PTT was lower along the short axis compared with the long axis. SWV may be useful in evaluating the severity of degenerative disease of arch-supporting structures, but further study is needed before this technique can be applied clinically. Level III, case-control study.