Sharp Angle Research Articles

Short-term effects of laparoscopic sleeve gastrectomy combined with reconstruction of the acute His angle on postoperative gastroesophageal reflux disease

Objective: To compare the short-term efficacy of laparoscopic sleeve gastrectomy (LSG) combined with sharp His angle reconstruction (LSG-His) versus traditional LSG. Methods: In this retrospective cohort study we collected clinical data of patients with obesity who had undergone LSG or LSG-His in the Department of General Surgery, Beijing Chaoyang Hospital, Capital Medical University, from January to June 2022. After excluding patients with incomplete follow-up data and those with hiatal hernia, 83 obese patients, of which 39 who had undergone LSG (LSG group) and 44 who had undergone LSG-His (LSG-His group), were included in the study. The basic steps in LSG-His are the same as in conventional LSG. After continuous suturing of the gastric staple line, one stitch is placed between the proximal side of the gastric greater curvature staple line and the proximal side of the gastric fundus posterior wall with the left diaphragm, and another stitch between the right side of the gastric fundus and the esophagus, reconstructing the sharp His angle. Clinical data, postoperative complications, and follow-up data on weight loss and gastroesophageal reflux disease (GERD) symptoms 1-, 3-, 6-, and 12-months post-discharge were compared between the two groups. GERD symptoms were assessed using the Gastroesophageal Reflux Disease Questionnaire and Reflux Diagnostic Questionnaire. Results: There were no significant differences between the two groups in baseline characteristics, length of hospital stay, hospitalization costs, intraoperative bleeding, postoperative nausea and vomiting, dysphagia, or postoperative complications (all P>0.05). Compared with the LSG group, the LSG-His group had significantly longer operative times (92 [80, 100] minutes vs. 80 [70, 100] minutes, U=2.227, P=0.026), higher postoperative 24-hour pain scores (5.2±1.8 vs. 4.3±1.9, t=-2.065, P=0.041), and higher rates of morphine use (70.5% [31/44] vs. 46.2% [18/39], χ²=4.519, P=0.025). The incidence of new-onset GERD 12 months postoperatively was significantly lower in the LSG-His than the LSG group (10.7% [3/28] vs. 61.3% [19/31], χ²=14.00, P<0.001). According to changes in Gastroesophageal Reflux Disease Questionnaire and Reflux Diagnostic Questionnaire scores, the LSG-His group also had significantly lower rates of exacerbation of GERD (2/16 vs. 5/8, χ²=4.27, P=0.021) and higher rates of GERD remission (12/16 vs. 2/8, χ²=3.62, P=0.032) than did the LSG group. Additionally, excess weight loss rates were significantly higher in the LSG-His group at 3 months [(54.7± 18.7)% vs. (46.5±15.0)% , t=-2.166, P=0.033], 6 months [(73.8±24.7)% vs. (64.0±19.1)% , t=-2.018, P=0.047], and 12 months [(82.9±26.7)% vs. (72.2±19.3)%, t=-2.063, P=0.042] than in the LSG group. Conclusion: Compared with LSG, LSG-His is safe and feasible and achieves better short-term control of postoperative GERD and more effective weight loss. Further large-scale, long-term, prospective studies are needed to confirm the long-term efficacy of LSG-His.

Transradial stent angioplasty using double guide wires for severe stenosis of vertebral artery ostium at a lower location

To investigate the effect and safety of transradial stent angioplasty using double guide wires for severe stenosis of vertebral artery ostium at a lower location. Patients with severe stenosis of the vertebral artery ostium at a lower location treated with transradial stent angioplasty were retrospectively enrolled. All the clinical and endovascular treatment data were analyzed. Thirty-nine patients were enrolled. A low location of the vertebral artery ostium was present in 33 (84.6%) patients and an ultra-low location in 6 (15.4%). Transradial stent angioplasty was performed in all patients. In one patient who had a tortuous radial artery, the transradial access was failed. In the other 38 (97.4%) patients, transradial stent angioplasty was all successful. The sharp angle formed between the vertebral artery and the subclavian artery was significantly (P<0.0001) increased from 15°-65° (36°±11°) before to 70-125° (90°±17°) after insertion of a support guide wire. No damage was found in all support guide wires. Thirty-nine stents were deployed, and the preoperative stenosis rate of 70%-98% (85%±13%) was significantly (P<0.0001) decreased to 0-25% (16%) immediately after stenting. Six-12 months after surgery, 29 (74.4% or 29/39) patients were followed up with imaging, and nine (31.0%) patients experienced in-stent restenosis, with endovascular retreatment being performed in 3 (33.3%) patients. Transradial stent angioplasty using double guide wires is safe and effective for the treatment of severe stenosis of the vertebral artery ostium at a lower location even though more studies are necessary to confirm this.

A novel subsurface damage model in diamond wire sawing of silicon wafers

The subsurface damages (SSDs) generated during fixed abrasive diamond wire sawing (DWS) of silicon wafers can reduce the fracture strength and increase the breakage probability of these wafers. It is crucial to accurately evaluate these SSDs. A theoretical model of SSD depth is developed for the fixed abrasive DWS of silicon wafers considering the size effects of material properties, micro-geometries of abrasive grits, and inclination/interaction effects of subsurface cracks. A series of silicon wafers are processed, and the silicon material properties, diamond wire parameters, and surface/subsurface morphologies of silicon wafers are measured. The model is experimentally validated and then used to study the effects of processing parameters on inclination/interaction effects, cutting behaviors, and SSDs. The results show that the model has a relative error of less than 5.0% after revealing that the inclination/interaction parameters, cutting behavior parameters, and SSD depth almost follow a normal distribution, with a maximum distribution probability ranging from 30% to 50%. The average inclination angle is approximately 30°, the average cutting depth is in the range of one to two hundred micrometers, the average load is a few millinewtons, and the SSD depth is in the range of a few micrometers. With an increasing density of abrasive grit, a decreasing feed rate, or an increasing wire speed, the interaction effect becomes more pronounced, while the inclination angle, cutting depth, load, active grit ratio, and SSD depth decrease. When the protrusion height increases, or the half sharpness angle or tip radius of abrasive grit decreases, there is an increase in the cutting depth, load, active grit ratio, or SSD depth. The inclination angle decreases as the protrusion height, half sharpness angle, or tip radius increases. This research helps to understand the cutting mechanism and evaluate the SSDs during the DWS of silicon wafers.

A groundbreaking electrocardiographic observation: “Isoelectric horizontal ST-segment with sharp ST-T angle” a novel sign for acute coronary syndrome

Consecutive suspected acute coronary syndrome (ACS) cases were categorized into three groups: Group-1 (ST-depression), Group-2 (T-inversion), and Group-3 (remaining cases). Group-3 was subclassified into isoelectric horizontal ST-segment with sharp ST-T-angle (IHST) positive and IHST negative groups. They underwent serial high-sensitive Troponin-I testing. ACS incidence was 77.96 %, with 33.02 %, 15.96 %, and (15.04 %, 35.96 %) of patients in Groups 1, 2, and 3 (IHST positive, IHST negative), respectively. The presence of IHST exhibited higher sensitivity than T-inversion and greater specificity than ST-depression in detecting ACS. The presence of IHST sign additionally detected 15.04 % of ACS. The presence of IHST was significant among group-3 (p = 0.008) as well as the overall ACS cases (p = 0.048).

Optimization of Advance Drainage Borehole Layout Based on Visual Modflow

It is an effective measure to prevent water damage in coal mines in order to construct drainage boreholes in water-filled aquifers of a working face roof. The hydrogeological parameters of the roof water-filled aquifer and the parameters of the drainage borehole are closely related to the underground drainage effect. Taking the 3085 working face of the Donghuantuo Mine in Kailuan as an example, the influence degree of hydrogeological parameters and hydrophobic borehole parameters on the amount of drainage water was analyzed using the generalized gray correlation degree. Based on Visual Modflow, the 3D groundwater visualization model was established and the dredging borehole was generalized into the pumping borehole. By changing the main influencing factors, the design optimization of the advanced hydrophobic borehole was discussed. The results showed that the aquifer thickness had a great influence on the amount of water discharged, and the influence degree of the sharp angle between the formation and the direction of drilling, the depth of the final hole, the azimuth angle of drilling, the dip angle of drilling, the elevation of the final hole and the elevation of the borehole on the amount of water discharged decreased successively. Based on the simulation calculation, it could be observed that the hydrophobic borehole should be placed in a position with a larger accumulated thickness of the aquifer to have a better effect of hydrophobic depressurization.

A Study on Imaging Risk Factors for Hip Osteoarthritis.

Due to low prevalence and few studies, the morphologic risk factors for hip osteoarthritis (HOA) in Chinese population remain unknown. The purpose of this study was to investigate the relationship between 10 radiographic parameters measured via anteroposterior pelvic X-ray radiography and HOA in Chinese population. Thirty-three patients who required total hip arthroplasty for unilateral HOA (2017-2022) and 132 healthy individuals were selected for this case-control study. We measured 10 radiological parameters via anteroposterior pelvic X-ray radiography, which were sharp angle, center edge angle, sourcil angle, neck shaft angle, α angle, pelvic height, pelvic width, femoral head diameter, femoral neck width, and ratio of the femoral head diameter to the femoral neck width. After measurements were obtained, logistic regression analysis was utilized to calculate the adjusted odds ratios (ORs) for confounding variables such as age, sex, and body mass index (BMI). Receiver operating characteristic (ROC) curves were utilized to determine the proportional risk contribution (PRC) of each radiographic factor. After adjustment for confounding factors, individuals with a larger sourcil angle (SA) (OR = 4.89, 95% CI 1.66-14.42, p = 0.004), larger α angle (OR = 4.14, 95% CI 1.53-11.23, p = 0.005), and wider femoral neck (OR = 5.27, 95% CI 1.50-18.51, p = 0.01) were found to have a greater risk of developing HOA. Among all radiographic parameters, the SA demonstrated the greatest risk contribution (PRC = 13.695%). Radiographic parameters correlate with the incidence of HOA. The SA is probably the most powerful of all the parameters related to HOA.

Position and frequency of lateral canals in carnassial teeth of dogs

Carnassial teeth, as one of the most important teeth in dogs, are commonly affected by different types of injuries and pathological disorders, which require endodontic treatment. Lateral canals, which leave the main root canal, and apical deltas are present in the root canal system of dogs. These canals represent small branches that leave the main root canal at a sharp angle and terminate in a region of the periodontal ligament on the external root surface. In this study, 200 teeth were included, of which 100 were superior fourth premolars and 100 were inferior first molars. Lateral canals were present in a total of 30 roots of superior fourth premolar teeth, whereas in inferior first molars, these canals were found in 3% of roots. In superior fourth premolars, lateral canals were mostly present in the apical third, 86%, while 14% were present in the middle third of the root. In inferior first molars, lateral canals were found in 3% of the roots, 2% in the apical third and 1% in the middle third of the roots. The knowledge of the complex root canal morphology is essential for any endodontic treatment. Due to the presence and frequency of lateral canals, it is imperative to perform more thorough cleaning and instrumentation while performing endodontic treatment on superior fourth premolars compared to inferior first molars.

Can acetabular dysplasia be measured on axial CT? A measurement for trauma surgeons

BackgroundAcetabular dysplasia has been theorized as a risk factor instability amongst common acetabular fractures, such as posterior wall (PW) fractures. However, common radiographic measurements often cannot be acquired in trauma patients. We evaluated axial computed tomography (CT) scans to identify novel, easily-obtained measurements that correlate with acetabular dysplasia for use in surgical indications and planning. MethodsPatients with known acetabular dysplasia undergoing elective periacetabular osteotomy were selected. A different group of patients without pelvic ring or acetabular fractures from an institutional trauma registry were selected as a comparison group. Standard indices of dysplasia were collected, such as center-edge angle (CEA). Acetabular geometric measurements were taken at three axial levels: 0 – cranial CT slice at the dome; 1 – cranial CT where the dome is an incomplete circle; 2 – cranial CT with femoral head visible. Distances between levels were also calculated: Levels 0–1 (Dome Height; DH), Levels 1–2 (Head Height; HH), and Dome-Head Difference (DH – HH = DHD). ResultsDH, HH, and DHD were all significantly correlated with CEA, Tonnis angle, and Sharp's angle in dysplastic hips. All dysplastic hips had DH ≤ 2.5 mm and HH ≥ 1.25 mm. DHD ≤ 0 mm was most specific (93.6 % sensitive, 77.3 % specific) for predicting dysplasia. ConclusionDH ≤ 2.5 mm, HH ≥ 1.25 mm, and DHD ≤ 0 mm were independently associated with dysplasia on axial CT scans. These measurements may be quickly and easily used by trauma surgeons to assess a trauma-based axial CT scan for acetabular dysplasia.

Patients With Dysplasia Achieve Similar Outcomes and Survivorship to Nondysplastic Patients 10 Years After Hip Arthroscopy for Femoroacetabular Impingement

To determine the long-term outcomes of hip arthroscopy (HA) for femoroacetabular impingement (FAI) in the presence of concomitant lateral rim dysplasia compared with a matched control group. Patients undergoing HA between January 2009 and October 2013 with minimum 10-year follow-up were reviewed. The inclusion criteria consisted of patients undergoing HA for FAI with evidence of lateral rim dysplasia (lateral-center edge angle [LCEA] < 25°). Patients with lateral rim dysplasia were matched to patients with an LCEA greater than 30° based on sex, Tönnis grade, and age. Outcomes included survival (avoidance of total hip replacement [THR]), repeated HA, and patient-reported outcomes (PROs). Survivorship was assessed using a Kaplan-Meier curve and log rank test, whereas revision rates between groups were assessed using χ2 analysis. Between- and within-group analyses of PROs were conducted using the Mann-Whitney U test and Wilcoxon signed rank test, respectively. The proportion of cases achieving the patient acceptable symptom state was compared between groups using χ2 analysis. This study comprised 46 dysplasia cases and 90 control cases. There was no statistically significant difference between groups in baseline metrics apart from the LCEA (P < .001), Sharp angle (P < .001), and Tönnis angle (P < .001). By 10 years postoperatively, 9% of dysplasia cases and 4% of control cases underwent conversion to THR. There was no statistically significant difference between groups in survival or revision rates. Both groups reported improvements in PROs, and there was no difference between PRO scores at either time point. Excluding cases that underwent THR, 84% and 83% of dysplasia and control cases, respectively, achieved the patient acceptable symptom state. HA for symptomatic FAI is a successful treatment in cases in which dysplasia is present. Low complication rates, comparable outcomes to cases without lateral rim dysplasia, and a high survivorship rate of 91% at minimum 10-year follow-up are observed. Increasing Tönnis angle preoperatively may increase the risk of THR conversion. Level IV, retrospective cohort study.

Generalized Joint Hypermobility Is Associated with Type-A Hip Dysplasia in Patients Undergoing Periacetabular Osteotomy.

Joint hypermobility may be associated with developmental dysplasia of the hip (DDH), but no definite conclusion has been reached. On the basis of long-term clinical observations, we hypothesized that joint hypermobility was associated with the occurrence, imaging findings, and clinical symptoms of DDH. We conducted a case-control study that included 175 Chinese Han patients between 13 and 45 years of age with Hartofilakidis type-A hip dysplasia. All of these patients underwent periacetabular osteotomy (PAO) between November 2021 and February 2023. An additional 76 individuals of comparable age and sex but without hip dysplasia were selected from the general population to serve as healthy controls. The Beighton 9-point scoring system was used to evaluate joint hypermobility, and a score of ≥4 was defined as generalized joint hypermobility. Standing anteroposterior pelvic radiographs were reviewed. For patients with DDH, the lateral center-edge angle, Tönnis angle, Sharp angle, lateralization of the femoral head, and patient-reported outcomes (iHOT-12, HHS, and WOMAC) were also collected to determine the radiographic severity or clinical symptoms of DDH. Patients with DDH had an elevated prevalence of generalized joint hypermobility compared with that in the healthy population (27% versus 12%; p = 0.009). Among patients with DDH, those with concomitant generalized joint hypermobility had lower lateral center-edge angles (3.55° versus 9.36°; p = 0.012), greater lateralization of the femoral head (13.78 versus 12.17 mm; p = 0.020), greater standardized lateralization of the femoral head (0.64 versus 0.54; p = 0.009), and lower iHOT-12 scores (35.22 versus 40.96; p = 0.009) than did those without concomitant generalized joint hypermobility. Further multivariable linear regression analysis revealed that higher Beighton scores and younger age were predictive of more severe hip dysplasia. However, the Beighton score was not found to be independently associated with patient-reported outcomes according to multivariable linear regression analysis. The prevalence of generalized joint hypermobility was greater in patients with DDH than in healthy controls. A higher degree of joint hypermobility was also correlated with more severe hip dysplasia. These results suggest that joint laxity, in addition to bone or cartilage factors, is an important factor related to DDH. Prognostic Level III. See Instructions for Authors for a complete description of levels of evidence.

Effects of cutting tool geometry on material removal of a gradient nanograined CoCrNi medium entropy alloy.

CoCrNi medium-entropy alloys (MEAs) have attracted extensive attention and research because of their superior mechanical properties, such as higher ductility, strength, and toughness. This study uses molecular dynamics (MD) simulations to investigate the cutting behavior of a gradient nanograined (GNG) CoCrNi MEA. Moreover, it explores the influence of relative tool sharpness and rake angle on the cutting process. The results show that an increase in the average grain size of the GNG samples leads to a decrease in the average resultant cutting force, as predicted by the Hall-Petch relationship. The deformation behavior shows that grain boundaries are crucial in inhibiting the propagation of strain and stress. As the average grain size of the GNG sample increases, the range of shear strain distribution and average von Mises stress decreases. Moreover, the cutting chips become thinner and longer. The subsurface damage is limited to a shallow layer at the surface. Since thermal energy is generated in the high grain boundary density, the temperature of the contact zone between the substrate and the cutting tool increases as the GNG size decreases. The cutting chips removed from the GNG CoCrNi MEA substrates will transform into a mixed structure of face-centered cubic and hexagonally close-packed phases. The sliding and twisting of grain boundaries and the merging of grains are essential mechanisms for polycrystalline deformation. Regarding the cutting parameters, the average resultant force, the material accumulation, and the chip volume increase significantly with the increase in cutting depth. In contrast to sharp tools, which mainly use shear deformation, blunt tools remove material by plowing, and the cutting force increases with the increase in cutting-edge radius and negative rake angle.

HF/HR VSP acquisition, processing, and interpretation in the deviated section of the high angle geothermal borehole of Grigny GGR5, targeting intra Dogger thin, porous beds.

Defining 5m thin, or even thinner, porous reservoir beds was the feasibility objective assigned to the High Frequency/High Resolution (HF/HR) look ahead VSP survey to be recorded in the deviated section of a geothermal production well drilled down to the top of the carbonate Dogger aquifer in the Paris basin, around 1500m in vertical depth, with a landing angle of 65°. The idea was to predict the depth of the first porous bed(s) to be drilled at high angle, and to determine the minimal DLS (Dog Leg Severity) to be applied by the driller after setting a production casing at the top Dogger level and changing the drilling fluid composition, so as to avoid directional drilling with sharp angles. A 50-100m vertical depth range was targeted for the acoustic impedance to be predicted below the top Dogger carbonate aquifer. Besides, a Pilot Hole (PH) was drilled prior to the high angle leg to assess with full reliability the depth of productive thin beds to be subsequently drilled at high angle. These actions were undertaken within a global R&amp;D project named “SISMOSUB” aiming reservoir characterisation, conducted by the reservoir and drilling engineers of GEOFLUID/GPCIP, in a partnership with IFPEN, and partially financed by ADEME (French Agency for Ecological Transition). High Frequency (HF) VSP still represents a frontier seismic domain to investigate, for which technical difficulties are piling up: First, the surface fix source needs to be extremely repeatable and preferably deliver an increased amount of HF energy to compensate somehow for the higher loss of seismic amplitudes with high frequency. Second, downhole receiver tool or toolstring may not present constant vector fidelity of 3 component reception over the whole recording frequency range, mainly in high frequency, due to mechanical coupling characteristics of the VSP tool hardware and the open borehole ruggedness; in cased hole, the mechanical coupling of the VSP tool to the formation is insured by a good cementing quality between casing and borehole wall. Third, the physics of the seismic attenuation is not fully understood and depends on several factors, mainly viscoelasticity and heterogeneity, potentially variable in depth and laterally to the wellbore. Additionally, the geometrical spreading represents the main factor of amplitude decay, independent from frequency, and can be estimated at processing stage. Surprisingly, the VSP image produced underneath the deviated hole section evidenced a faulted structure. A remarkable abrupt amplitude loss of high frequencies above 120Hz occurs where the direct P-wave ray crosses one of the confirmed minor faults before reaching Total Depth (TD); secondary downgoing arrivals appear locally in depth, mainly in the high frequencies, which are not strictly parallel to the first P-wave arrival...

Effect of lumbosacral transitional vertebra on developmental alterations of the hip: a quantitative investigation of the lumbo-pelvic-hip complex via whole-body computed tomography.

Lumbosacral transitional vertebra (LSTV) is a common spinal variant, with the reported prevalence varying from 8.1% to 36%. LSTV has been shown to alter the lumbo-pelvic parameters and reduce the benefits of total hip arthroplasty, but the specific effects of LSTV on hip development remain unclear. The aim of this study was thus to investigate the impact of LSTV on developmental alterations of the hip. A total of 310 individuals were categorized into three groups according to whole-body computed tomography (CT) imaging: a group with sacralization of 23 presacral vertebrae (PSV) (n=102), a group with lumbarization of 25 PSV (n=108), and a normal control group with 24 PSV (n=100). Quantitative parameters of the lumbo-pelvic-hip complex (LPHC) including lumbar lordosis (LL), pelvic incidence (PI), pelvic tilt (PT), sacral slope (SS), axial and sagittal acetabular anteversion angle (AAA), center-edge (CE) angle, Sharp angle, and femoral neck-shaft angle (FNSA) were measured and analyzed. Statistical analyses were used to compare the differences of these quantitative parameters among the three groups and to assess the relationship between hip and lumbar-pelvic parameters. Significant differences between each pair of three groups and the LSTV subgroups were only found in the sagittal AAA (left side: P=0.008; right side: P<0.001), with no differences found for the other parameters. Compared to the normal group (24 PSV), both the 23 PSV and 25 PSV groups exhibited increased values in the sagittal AAA, especially in the right side of the 23 PSV group. Only the sagittal AAA showed low-to-moderate positive correlations with pelvic parameters of PI (r=0.195-0.429; P=0.001-0.08) and PT (r=0.239-0.605; P=0.001-0.03). Variations of LSTV are correlated with the hip anatomical development via LPHC transmission and may potentially reduce the sagittal acetabular coverage, particularly in the 23 PSV subtype on the right side.

Acetabular coverage exerts minimal influence on femoral head collapse and the necessity for surgical intervention in patients with osteonecrosis of femoral head

PurposeThe acetabular coverage in osteonecrosis of the femoral head (ONFH) affects the need for surgical intervention, and the collapse of the femoral head remains unclear. This study aimed to evaluate the relation between the acetabular coverage and the need for surgical treatment and femoral head collapse.MethodsThe study included 158 patients with 252 hips with glucocorticoid administration and idiopathic ONHF without osteoarthritis changes. The mean age at the first visit was 45.2 years, and the mean follow-up period was 92.2 months. All ONFH hips were subsequently divided into two groups: those needing surgical intervention and those without surgery. Additionally, it divided 167 initially non-collapsed hips into those that either later collapsed or not. Radiographic parameters with the centre-edge angle, acetabular roof obliquity, sharp angle, and necrotic location, following the guidelines of the Japanese Investigation Committee, were evaluated.ResultsThere were no significant differences in radiographic parameters between the 106 hips that underwent surgery and the 146 hips without surgery. Among the 167 hips without initial collapse, 91 eventually collapsed while 76 did not; their radiographic findings have no significant differences. The necrotic locations were significantly larger in hips requiring surgical intervention or femoral head collapse. Furthermore, 21.8% (55 out of 252 hips) had acetabular dysplasia, which did not significantly correlate with the necessity for surgical treatment or the incidence of femoral head collapse.ConclusionsAcetabular coverage has little effect on the necessity for surgical treatment and femoral head collapse in ONFH patients over a long-term follow-up.

Procedural generation of geometric patterns for thin shell fabrication

This paper addresses the design of surface shells as assemblies of tileable, flat geometric patterns with predictable performance in response to mechanical stimuli. We design a family of tileable and fabricable patterns represented as triangle meshes, which can be assembled for creating surface tessellations. First, a regular recursive subdivision of the planar space generates different geometric configurations for candidate patterns, having interesting and varied aesthetic properties. Then, a refinement step addresses manufacturability by solving for non-manifold configurations and sharp angles that would produce disconnected or weak patterns. We devise a strategy for creating continuous variations on the geometry of individual patterns, in both aesthetics and behavior, to enrich the catalog of available designs. Finally, we simulate our patterns to evaluate their mechanical response when loaded in different scenarios targeting out-of-plane bending. Through a simple browsing interface, we show that our patterns span a variety of different bending behaviors. The result is a catalog of patterns with varied aesthetics and predefined mechanical behavior, to use for the direct design of mechanical metamaterials. To assess the feasibility of our design-to-fabricate approach, we show fabricated 3D objects with different curvatures, and compare physical and simulated experiments.

Anatomical features of the mastoid segment of the facial canal.

Considering the tortuous course of the facial canal that houses the facial nerve, the stylomastoid artery and the homonymous vein, its morphological features are of great clinical significance in otologic, maxillofacial, oncologic, reconstructive and plastic surgery of the head and neck. The aim of this paper was to determine the individual specific features of the mastoid segment of facial canal and of the stylomastoid foramen. The study was carried out on 82 temporal bones (41 right/41 left), at the Department of anatomy and clinical anatomy of Nicolae Testemitanu State University of Medicine and Pharmacy of the Republic of Moldova. The morphometry of the mastoid segment of the facial canal and of the stylomastoid foramen was performed. The morphometric parameters were statistically analyzed by descriptive and inferential statistics methods. The mastoid segment exited the facial canal by an obtuse, right and sharp angles, with a mean value of 113.1 ± 21.80° (right/left - 112.1 ± 23.85°/114.1 ± 19.76°), p = 0.701. The mean length of the mastoid segment was 15.1 ± 3.78 mm (right/left - 15.7 ± 3.66 mm/14.5 ± 3.84 mm), p = 0.153. The longitudinal diameter of the stylomastoid foramen had a mean of 3.0 ± 0.93 mm (right/left - 3.3 ± 0.96 mm/2.7 ± 0.81 mm), p = 0.007. The transverse diameter had a mean of 2.6 ± 0.74 mm (right/left - 2.9 ± 0.80 mm/2.4 ± 0.60 mm), p = 0.012. In otologic surgery and particularly in mastoidectomy, it should be taken into consideration that the mastoid segment of the facial canal could exit the temporal bone by a sharp, right and obtuse angles that along with high morphological variability of the stylomastoid foramen might be a predisposal factor for Bell's palsy.

An in-depth analysis of young adults with osteonecrosis secondary to developmental dysplasia of the hip who underwent total hip arthroplasty

BackgroundPatients with osteonecrosis of the femoral head secondary to DDH frequently require total hip arthroplasty (THA), but it is not well understood which factors necessitate this requirement. We determined the incidence of THA in patients who have osteonecrosis secondary to DDH and factors associated with need for THA.MethodsWe included patients who received closed or open reductions between 1995 and 2005 with subsequent development of osteonecrosis. We determined osteonecrosis according to Bucholz and Ogden; osteoarthritis severity (Kellgren-Lawrence), subluxation (Shenton’s line); neck-shaft angle; and acetabular dysplasia (centre-edge and Sharp angles). We also recorded the number of operations of the hip in childhood and reviewed case notes of patients who received THA to describe clinical findings prior to THA. We assessed the association between radiographic variables and the need for THA using univariate logistic regression.ResultsOf 140 patients (169 hips), 22 patients received 24 THA (14%) at a mean age of 21.3 ± 3.7 years. Associated with the need for THA were grade III osteonecrosis (OR 4.25; 95% CI 1.70-10.77; p = 0.0019), grade IV osteoarthritis (21.8; 7.55–68.11; p < 0.0001) and subluxation (8.22; 2.91–29.53; p = 0.0003). All patients who required THA reported at least 2 of: severe pain including at night, stiffness, and reduced mobility. Acetabular dysplasia and number of previous operations were not associated with the need for THA.ConclusionsWe identified a 14% incidence of THA by age 34 years in patients with osteonecrosis secondary to DDH. Grade III osteonecrosis (global involvement femoral head and neck) was strongly associated with THA, emphasising the importance to avoid osteonecrosis when treating DDH.

Analysis of risk factors for failed closed reduction in pediatric Gartland Type III supracondylar humerus fracture

PurposeGartland Type III supracondylar humerus fractures are commonly treated using closed reduction followed by percutaneous pin fixation. However, conversion to open reduction may be necessary if closed reduction fails. This study aimed to identify risk factors associated with failed closed reduction and provide a theoretical basis for clinical decision-making in the treatment of Gartland Type III fractures. MethodsA retrospective analysis was conducted on children with Gartland Type III supracondylar humerus fracture who underwent surgical treatment between April 2017 and June 2018. Based on whether or not the closed reduction was successful, patients were split into the open reduction group and the closed reduction group. Within the closed reduction group, subgroup analysis based on surgery duration was carried out. Data were collected from medical records and X-ray images. Univariate and multivariate regression analyses were utilized to evaluate the relationship between variables and failed closed reduction. ResultsThe study included 36 patients in the open reduction group and 135 patients in the closed reduction group. Multivariate analysis revealed that the presence of angle (P=0.024, OR=3.199), rotation (P=0.000, OR=6.359), skin creases (P=0.013, OR=4.077), anterior-posterior displacement ratio (P=0.011, OR=4.337), fracture angle in the anteroposterior view (P=0.014, OR=0.939), and fracture distal displacement direction (P=0.002, OR=5.384) were independent risk factors for failed closed reduction. Subgroup analysis showed that fracture distal displacement direction (P=0.013), skin folds (P=0.013), lateral displacement ratio (P=0.016), and anterior-posterior displacement value (P=0.005) significantly influenced the duration of closed reduction surgery. ConclusionThe presence of sharp angle or rotation at the fracture ends, skin folds on the anterior elbow, minor anterior-posterior displacement of the fracture, higher medial inclination of the fracture plane, and distal fracture displacement towards the radial side are independent risk factors for failed closed reduction in pediatric Gartland Type III supracondylar humerus fracture.

Less Acetabular Coverage Predicts the Failure of Core Decompression for Osteonecrosis of the Femoral Head: A Retrospective Cohort Study.

It is unclear whether less acetabular coverage is associated with the failure of core decompression (CD) for osteonecrosis of the femoral head (ONFH). This study aimed to investigate the clinical outcomes of CD for ONFH with small- or medium-sized pre-collapse lesions, and determine what factors, especially acetabular anatomical parameters, predict the failure of CD. Between January 2010 and December 2022, we retrospectively reviewed 269 consecutive CDs in 188 patients diagnosed with ONFH with small- or medium-sized pre-collapse lesions. The Kaplan-Meier method was used to evaluate the survival rate of CD for ONFH with progression of collapse or conversion to total hip arthroplasty (THA) as the endpoint. Univariate and multivariate logistic regression analyses were conducted to identify the potential risk factors for the failure of CD. Receiver operating characteristic (ROC) curve analysis was further performed with conversion to THA as the endpoint to determine the predictive value of these factors. The overall 5-year survival rate of CD for ONFH with small- or medium-sized pre-collapse lesions was 74.3% (95% confidence interval (CI) 69.0%-81.1%) with progression of collapse as the endpoint and 83.9% (95% CI 79.3%-88.7%) with conversion to THA as the endpoint. Univariate logistic regression analysis showed that bilateral affected hips was significantly associated with progression of collapse, and center-edge angle (CEA), sharp angle, acetabular head index (AHI), as well as acetabular depth ratio (ADR) were significantly associated with both progression of collapse and conversion to THA. Multivariate logistic regression analysis further indicated that CEA and AHI were independent risk factors for both progression of collapse and conversion to THA. ROC curve analysis with conversion to THA as the endpoint revealed that the cutoff values for CEA and AHI were 26.8° (sensitivity = 74.4%, specificity = 78.6%, area under the curve (AUC) = 0.809) and 79.8 (sensitivity = 78.4%, specificity = 73.8%, AUC = 0.818), respectively. CD showed satisfactory clinical outcomes for ONFH with small- or medium-sized pre-collapse lesions where less acetabular coverage with a CEA < 26.8° or AHI < 79.8 was identified as an independent risk factor for the failure of CD.

Optofluidic SERS based on Ag nanocubes with high sensitivity for detecting a prevalent water pollutant.

To enhance the integration and practical applicability of the Raman detection system, silver nanocubes (Ag NCs) were synthesized using a polyol method. A liquid-liquid interface approach was employed to transfer a monolayer of Ag NCs "film" onto a SiO2 substrate, resulting in the fabrication of a highly sensitive and uniform surface-enhanced Raman scattering (SERS) substrate denoted as "Ag NCs@SiO2." The electromagnetic field distribution of various dimers on the Ag NCs@SiO2 was analyzed using finite difference time domain (FDTD) software. The results reveal that the electromagnetic enhancement effect is most pronounced in cube-cube dimers, indicating that Ag NCs exhibit superior localized surface plasmon resonance (LSPR) response due to their well-defined geometric regularity and sharp geometric angles. For Rhodamine 6G (R6G) probe molecules, the Ag NCs@SiO2 shows ultrahigh sensitivity, with a limit of detection (LOD) of 10-12 mol/L, and the enhancement factor (EF) can reach 1.4 × 1010. The relative standard deviation (RSD) at the main characteristic peaks is below 10%, demonstrating good consistency in substrate performance. In addition, the Ag NCs@SiO2 modified with hexanethiol exhibits high sensitivity, uniformity, and repeatability in detecting for pyrene, with the LOD of 10-8 mol/L and a minimum RSD of 6.09% at the main characteristic peak, and effective recognition capabilities for pyrene and anthracene in mixed solutions. Finally, chemisorption and physisorption strategies were prepared in optofluidic channels and experimentally compared, enabling real-time detection of the pyrene solution. This method can achieve a rapid detection and precise differentiation of polycyclic aromatic hydrocarbons in a water pollutant.