Double Wire Research Articles

S1111 Post-ERCP Pancreatitis: Does Diet Matter?

Introduction: Post-ERCP pancreatitis (PEP) is one of the most feared and most common complications of an ERCP, with an incidence of approximately 9.7%. While several risk factors for PEP have been established, the relationship between post-procedure diet and PEP is not well understood. We sought to evaluate whether a regular diet immediately post-ERCP was associated with an increase in PEP. Methods: This was a retrospective study during which consecutive patients at two academic medical centers who underwent ERCP in 2021 were evaluated. Inclusion criteria were a) patients ≥ 18 years old; b) inpatient status prior to ERCP; c) no prior history of ERCP; d) no prior history of pancreatitis; e) no prior history of Sphincter of Oddi dysfunction. Data collected from these patients included patient demographics, ERCP procedure details, pre- and post- ERCP diet orders, and post- procedure complications. Association with PEP was evaluated using X2 and Fisher’s exact tests. Results: 100 consecutive patients met inclusion criteria and were included in this study. Overall, 74 patients (74%) received a modified post-ERCP diet, and 26 (26%) of patients received a regular post-ERCP diet. There was no significant difference in the incidence of PEP between these two groups (7/74 (9.4%) vs 0/26 (0%), p = 0.185). Cannulation type was found to be significantly associated with the development of PEP (standard cannulation, 2/72 (2.7%) vs other cannulation (double wire, needle knife, sphincteroplasty- assisted), 5/25 (20%), p=0.011). No other factors were found to have a significant association with the development of PEP (Table). Conclusion: In this cohort of 100 patients, post-ERCP diet choice was not found to be associated with the development of PEP. In fact, the only factor that was associated with PEP was a non-standard cannulation during ERCP, which is a well-established risk factor. The lack of association of post ERCP diet with PEP is an important finding because it is a common practice for endoscopists to recommend a modified consistency diet post ERCP to reduce the risk of PEP despite the lack of supporting evidence for this recommendation. Immediate advancement to a regular diet has significant benefits including aiding in patient recovery, reducing hospital length of stay, and improving patient satisfaction. Larger scale studies to corroborate this data in a prospective fashion are indicated. Table 1. - Factors Associated with the Development of Post-ERCP Pancreatitis Post-ERCP Pancreatitis Yes No p-value Main Exposure: Post-ERCP Diet, n (%) 0.1852 Modified 7 (9.46) 67 (90.54) Regular 0 26 (100.00) Demographic Characteristics Sex, n (%): 1.0000 Male 4 (7.27) 51 (92.73) Female 3 (6.67) 42 (3.33) Age in Years: 0.5122 Mean (SD) 58.29 (21.69) 63.46 (18.46) Comorbidities History of Pancreatitis, n (%) 1.0000 Yes 0 (0.00) 10 (100.00) No 7 (7.78) 83 (92.22) History of Cholelithiasis, n (%) 0.3411 Yes 0 (0.00) 19 (100.00) No 7 (8.64) 74 (91.36) ERCP Characteristics Indication, n (%) 0.8308 Benign Bile Duct Pathology 6 (8.45) 65 (91.55) Malignancy 1 (6.25) 15 (93.75) Benign Pancreas Duct Pathology 0 (0.00) 13 (100.00) Cannulation Type (N = 97*), n (%) 0.0116 Standard 2 (2.78) 70 (97.22) Other 5 (20.00) 20 (80.00) Sphincterotomy, n (%) 0.1856 Yes 4 (5.06) 75 (94.94) No 3 (14.29) 18 (85.71) Biliary Stent, n (%) 0.1139 Yes 6 (11.54) 46 (88.46) No 1 (2.08) 47 (97.92) Pancreatic Stent, n (%) 0.3108 Yes 2 (12.50) 14 (87.50) No 5 (5.95) 79 (94.05) Complexity Grade, n (%) 1.0000 Grade 3 1 (7.69) 12 (92.31) Grade 1-2 6 (6.90) 81 (93.10) Post-Procedure Fluid (mL, N = 81*), n (%) 0.9525 Mean (SD) 870.00 (710.28) 904.45 (778.64) Rectal Indomethacin Given, n (%) 0.1037 Yes 7 (9.86) 64 (90.14) No 0 (0.00) 29 (100.00) *N listed due to missing data for some patients at these data points

S2832 First Trimester Subcapsular Hepatic Hematoma Following Endoscopic Retrograde Cholangiopancreatography

Introduction: Endoscopic retrograde cholangiopancreatography (ERCP) is commonly utilized to treat pancreaticobiliary diseases and is considered safe in pregnancy. We describe a case of ERCP indicated for choledocholithiasis in a newly pregnant patient which resulted in a very rare complication related to guide wire trauma. Case Description/Methods: A 24-year-old female presented to the emergency department with right upper quadrant pain, fever, leukocytosis, and obstructive jaundice. Bloodwork revealed she was 8 weeks pregnant. Imaging studies showed acute cholecystitis and choledocholithiasis with a dilated common bile duct of 1.2 cm. Therapeutic ERCP was performed with minimal use of fluoroscopy to reduce fetal exposure. Double wire technique was utilized and the bile duct was successfully cannulated with a 0.025 mm angled-tipped hydrophilic wire. Sphincterotomy was performed, followed by sphincteroplasty. The bile duct was swept with a 12 mm balloon but only one stone was extracted. To avoid further fetal fluoroscopy exposure, double plastic stents were placed into the common bile duct and a single pigtail plastic stent was placed into the pancreatic duct. The following day, she became hemodynamically unstable. Labs suggested an improved cholestatic pattern and improved leukocytosis post ERCP decompression. Due to worsening hepatocellular injury and hemodynamic instability, a computed tomography angiogram was performed. A 3.9 cm subcapsular hepatic hematoma with capsular retraction and parenchymal distortion of the superior right hepatic lobe was found. Interventional radiology catheter embolization was attempted. Aggressive conservative management with blood transfusions and close monitoring successfully stabilized the patient. The patient ultimately had a spontaneous abortion and returned for an outpatient ERCP with biliary stent removal and stone extraction. Discussion: Although a very rare complication, this case does highlight the possibility of angled-tipped hydrophilic guide wire hepatic trauma and clinically significant bleeding. When strongly indicated, ERCP should be performed in people who are pregnant, but exposure to fluoroscopy should be minimized. Similar cases hypothesize that liver injury is attributable to traumatic damage to the intrahepatic biliary tree and hepatic parenchyma by the ERCP guide wire.Figure 1.: Computed tomography of the abdomen revealed a hypodense subcapsular collection on the right side of the liver. The bleed continues inferiorly and medially. A plastic pancreatic stent and a plastic biliary stent are also visible.

S1674 An Unusual Cause of Septic Shock Secondary to Lemmel Syndrome

Introduction: Lemmel syndrome (LS) is a rare cause of obstructive jaundice occurring in the absence of pancreaticobiliary tumors or choledocolithiasis and commonly caused by periampullary diverticulum (PAD) with an incidence of 1-27%. They are typically asymptomatic and underreported leading to complications in ∼5% of cases. Herein, we report a case of septic shock due to acute cholangitis secondary to Lemmel Syndrome. Case Description/Methods: A 58-year-old male with a medical history significant for hypertension who presented to the ER with right upper quadrant abdominal pain, jaundice, and multiple episodes of nonbloody-nonbilious emesis. On admission, the patient was febrile, tachycardic and hypotensive. Initial laboratory tests are shown in the Table. CT of the abdomen showed cholelithiasis and diffuse gallbladder thickening with no intra or extrahepatic biliary duct dilation. He developed septic shock requiring vasopressors. Blood cultures were positive for Escherichia coli, and antibiotics were administered. Emergent ERCP was performed due to the presence of acute cholangitis. He was found to have a large diverticulum located around the major ampulla. Double wire technique was performed to access the ventral pancreatic duct (VPD) and common bile duct (CBD). Fluoroscopic images revealed biliary tapering in the distal third but no visualized stones (Figure). Plastic stents were placed into the VPD and CBD and biliary sphincterotomy was performed. He also underwent laparoscopic cholecystectomy. The patient was discharged with resolution of symptoms. Discussion: The pathophysiology of LS is due to direct mechanical irritation of the diverticulum causing papillary fibrosis. Secondly, the diverticulum may cause sphincter of Oddi dysfunction. Thirdly, the distal CBD may be directly compressed by the periampullary diverticulum. The imaging modalities of choice to confirm the diagnosis include enhanced contrast CT and MRCP. ERCP allows for direct visualization of the duodenal diverticulum. Treatment of these entities is required if the patient becomes symptomatic. The mainstay of treatment is endoscopic sphincterotomy with stent placement or papillary balloon dilation. Due to the high recurrence rate, if endoscopic treatment fails then surgical approach via diverticulectomy is performed. It is important physicians remain vigilant regarding this condition since misdiagnosis leads to delay in therapy. The incidence of septic shock in LS is unknown and to our knowledge, there has only been one other reported case in literature.Figure 1.: A: Cholangiogram of biliary tree with no stones B: Cholangiogram with diverticulum, stent in place and no obvious stones C: Periampullary diverticulum after placement of CBD and pancreatic stent D: CT abdomen showing CBD stent in place with gallbladder sludge. Table 1. - Initial Laboratory Values Blood Chemistry Reference Range Sodium 137 mmol/L 136 - 145 mmol/L Potassium 3.8 mmol/L 3.5 - 5.3 mmol/L Blood urea nitrogen (BUN) 10.0 mg/dL 6 - 24 mg/dL Creatinine 1.0 mg/dL 0.6 - 1.2 mg/dL Lactic acid 5.3 mmol/L 0 – 2.0 mmol/L C-reactive protein 21.8 mg/dL 0.0-0.8 mg/dL TSH 1.1180 µIU/mL 0.400 - 4.500 µIU/mL Total bilirubin 3.3 mg/dL 0.2–1.2 mg/dL Direct bilirubin 1.94 mg/dL 0.0-0.3 mg/dL AST 487 U/L 10-36 U/L ALT 365 U/L 9-46 U/L Alkaline phosphatase 155 U/L 40-115 U/L Complete blood count White blood cell (WBC) 4.3x10 3/ uL 4.4 - 11 × 103/µL Hemoglobin 12.2 g/dL 13.5 - 17.5 g/dL Platelet 107 x103 /uL 150 - 450 × 103/µL

Thumb reconstruction after radical tumor resection using free osteocutaneous lateral arm flap with secondary humerus fracture—a case report

IntroductionMalignant diseases with infiltration of bony structures in the area of the phalanges or metacarpals require either amputation or complex reconstruction. The decision for reconstruction means to restore length, mobility, sensibility, stability as well as aesthetics.MethodsWe present a case of complex first ray reconstruction of the left hand using a free osteocutaneous lateral arm flap from the ipsilateral side. The reconstruction was performed after radical resection of an exulcerated squamous cell carcinoma, including the first metacarpal bone, trapezium, partial trapezoid and distal scaphoid as well as partial resection of the extensor pollicis longus, extensor pollicis brevis, abductor pollicis longus and flexor carpi radialis tendons. The osteosynthetic restoration was achieved distally by a double wire cerclage and a proximally by temporary K-wire suspension. Moreover, to reconstruct the extensor pollicis longus tendon the ipsilateral palmaris longus tendon was harvested and used. Postoperatively, a secondary humerus fracture occurred, which was initially attended by plate osteosynthesis. The fracture showed delayed healing, which was treated by re-plating and autologous cancellous bone.Results12 months postoperatively, the patient showed an excellent outcome with length preservation and good range of motion, sensibility, stability and aesthetic of the thumb. Furthermore, the quarterly tumor aftercare showed no evidence of recurrence.ConclusionThis case report showed that the free osteocutaneous lateral arm flap is a reliable solution for the reconstruction of the first ray with a great functional and aesthetic outcome. To prevent a secondary humerus fracture, a preventive plate osteosynthesis simultaneous with the osteocutaneous flap elevation should be considered.

Stereotaxic Core-Needle Biopsy in Assessing Intraductal Pathologic Findings at Ductography.

The purpose of this study was to analyze the capabilities of ductography (DG) to navigate stereotactic core-needle biopsy (sCNB) for localizing and differentiating intraductal benign and malignant proliferations of the breast in patients with pathological nipple discharge (PND). Patients underwent physical, radiological, ultrasound, endoscopic and histopathological examinations. The study included 183 patients. In 51, traditional DG was performed and in eight patients DG was performed using endoscopic mammoductoscopy (EMDS). A routine ductectomy labeled with methylene blue or propylene thread was performed in 81 patients. In 77 cases, a ductectomy was performed after double wire marking of intraductal proliferations (IDP) through the nipple and through the skin. In 26 patients, a preoperative sCNB under guidance of DG was performed. After sCNB 23/26 patients had benign IDP and three (11.5%) had invasive cancer. Breast surgery confirmed histology to be the gold standard in all patients, with the exception of 7 (26.9%) under the age of 45 years with benign IDP. These patients had watchful waiting and after 35 months of follow-up no signs of malignant growth were detected.DG was characterized by high (87.9%) sensitivity and low (33.3%) specificity. False positive rate was 25.9% and the cause was peripheral location of IDP (>3 cm from the nipple) in 57.1% and inadequate excision with leaving them outside the resection. This initial study on sCNB under the guidance of traditional or selective DG reports promising findings. Further studies are needed to determine whether preoperative histological assessment of pathologic intraductal lesions at DG would reduce the number of open surgeries with benign histology at sCNB.

Characterization of nickel-titanium alloy graded materials using double wire alternating current cross arc additive manufacturing

Using an arc heat source, the filling ratio of Ti6Al4V and Inconel 625 wires was controlled to manufacture a TiNi gradient material using wire arc additive manufacturing (WAAM). The effects of wire filling ratio on the microstructure of the deposition layer were studied through X-ray diffraction (XRD), scanning electron microscope (SEM), and differential scanning colorimetry (DSC). The mechanical performance was evaluated using compression, Vickers hardness, and surface wear testing. The results show that increasing the ratio of Inconel 625 filling wire can form Ti 2 Ni and TiNi strengthening phases in the deposition layer. The Ti 2 Ni and TiNi phases are evenly distributed over the region owing to the stirring of the molten pool by the arc, which improves the compression and surface wear performance of the WAAM parts. When the Inconel 625 wire filling ratio is 35%, the Vickers hardness reaches 600 HV and the compression strength increases to 2.15 GPa. However, excessive Ti 2 Ni phase will reduce toughness. As an Inconel 625 wire filling ratio lower than 35% can achieve a well-performing structure, five kinds of wire filling ratios were chosen to fabricate different gradient materials, and the microstructure, elemental distribution, phase composition, and mechanical properties were analyzed thoroughly. • We propose a new AC-WAAM method to manufacture Ni-Ti alloy Graded Materials. • By adding lnconel625 filling wire and titanium alloy filling wire at the same time. • Changing alloy compound by adjusted the speed rate of lnconel625 and TC4 filling wire. • The effects of wire feeding rate on the microstructure and mechanic were analyzed.

Homogenizing the composition of in-situ fabricated Ti2AlNb-based alloy via manipulating the droplet transfer mode of twin-wire arc additive manufacturing

The twin-wire arc additive manufacturing (TWAAM) technology is an effective method for the in-situ fabrication of Ti2AlNb-based alloys relative to conventional cast and wrought routes. However, composition segregation is still challenging in the field of in-situ TWAAM. To homogenize the chemical composition, here we proposed a novel single droplet pre-alloying transfer mode of TWAAM based on the original droplet transfer mode of double wires directly fed into the molten pool. The designed nominal composition of Ti-25Al-23Nb was set as the target alloy. The as-printed parts were investigated systematically. The results showed that this unique droplet transfer mode could not only improve the forming accuracy but also effectively mitigate the composition segregation. In addition, the inconsistency of microstructure caused by the composition segregation was successfully solved by this mode and appears a fully lamellar microstructure. The improvement of composition uniformity played a positive role in enhancing the mechanical properties of the alloy, in which the tensile strength of room and high temperature were improved by 76.8% and 74.1% respectively compared with our previous research. This work is of great significance to alleviate the composition segregation of intermetallics and further promote the in-situ TWAAM fabrication of Ti2AlNb-based alloys.

Effective operational capacity of brushcutter with different cutting tools

Brushcutters use different cutting tools with variations in operating capacity. Thus, the present study evaluate the effective operational capacity of a brushcutter equipped with different cutting tools in different areas of plant cover. It was subdivided into three experiments with 44 replicates of 4m2 each. The first was carried out in an area with plants cover with wheat and ryegrass, with blades of triple and double discs, and double wire. The second was carried out in another area with a cover composed of wheat, ryegrass, and fallow (composed of different species plants), with double- and triple-discs blades. The last experiment was carried out in a fallow area, with all cutting tools, except for the double wire. The results indicate that the brushcutter equipped with the triple-disc blade had greater operational capacity compared to the other cutting tools. For a working day of 8 h.day-1, the highest amount of mowed biomass was obtained with the triple-disc blade in areas with ryegrass and wheat cover, while for the fallow area, there is no significant difference between the double- and triple-disc blades. The adequate selection of the cutting tool contributes to the increase of the cut biomass in a shorter time, reducing the exposition of the operator to the vibrations and noise produced by the machine.

Morphological and Electrical Properties of Polythiophene Nanostructured Film Synthesized Using Atmospheric Pressure-Plasma Reactor with Double V-Shaped Bare Electrode

To synthesize a wide-area conducting polymer with improved morphology and electrical properties, we proposed a new atmospheric pressure (AP) plasma reactor with double V-shaped bare wire electrode operating at a low driven voltage to expand the plasma area for nanostructure synthesis. The two wires form a V-shape making a 60° angle at the edges and are joined together forming a cross, creating a canopy-like plasma medium in the plasma reactor center. Using the AP-plasma reactor, the polythiophene (PTh) nanostructured films are successfully synthesized with and without iodine doping. Moreover, the molecular structures and chemical properties of nascent and iodine-doped PTh films are compared, and the electrical resistivities of ex situ and in situ iodine-doped PTh nanostructures are also analyzed.

Treatment of Wehbe-Schneider typesⅠB and ⅡB bony mallet fingers with one-stage closed reduction and elastic compression fixation with double Kirschner wires

To investigate the effectiveness of one-stage closed reduction and elastic compression fixation with double Kirschner wires for Wehbe-Schneider types ⅠB and ⅡB bony mallet fingers. Between May 2017 and June 2020, 21 patients with Wehbe-Schneider type ⅠB and ⅡB bony mallet fingers were treated with one-stage closed reduction and elastic compression fixation using double Kirschner wires. There were 15 males and 6 females with an average age of 39.2 years (range, 19-62 years). The causes of injury were sports injury in 9 cases, puncture injury in 7 cases, and sprain in 5 cases. The time from injury to admission was 5-72 hours (mean, 21.0 hours). There were 2 cases of index finger injury, 8 cases of middle finger injury, 9 cases of ring finger injury, and 2 cases of little finger injury. The angle of active dorsiflexion loss of distal interphalangeal joint (DIPJ) was (40.04±4.02)°. According to the Wehbe-Schneider classification standard, there were 10 cases of typeⅠB and 11 cases of type ⅡB. The Kirschner wire was removed at 6 weeks after operation when X-ray film reexamination showed bony union of the avulsion fracture, and the functional exercise of the affected finger was started. The operation time was 35-55 minutes (mean, 43.9 minutes). The length of hospital stay was 2-5 days (mean, 3.4 days). No postoperative complications occurred. All patients were followed up 6-12 months (mean, 8.8 months). X-ray films reexamination showed that all avulsion fractures achieved bony union after 4-6 weeks (mean, 5.3 weeks). Kirschner wire was removed at 6 weeks after operation. After Kirschner removal, the visual analogue scale (VAS) score of pain during active flexion of the DIPJ was 1-3 (mean, 1.6); the VAS score of pain was 2-5 (mean, 3.1) when the DIPJ was passively flexed to the maximum range of motion. The angle of active dorsiflexion loss of affected finger was (2.14±2.54)°, showing significant difference when compared with preoperative angle (t=52.186, P<0.001). There was no significant difference in the active flexion angle between the affected finger (79.52±6.31)° and the corresponding healthy finger (81.90±5.36)° (t=1.319, P=0.195). At 6 months after operation, according to Crawford functional evaluation criteria, the effectiveness was rated as excellent in 11 cases, good in 9, and fair in 1, with an excellent and good rate of 95.24%. For Wehbe-Schneider typesⅠB and ⅡB bony mallet fingers, one-stage closed reduction and elastic compression fixation with double Kirschner wires can effectively correct the deformity and has the advantages of simple surgery, no incision, and no influence on the appearance of the affected finger.

The Method of Modal Parameters for the Wire Segments With Symmetrical Geometry and Singularity Expansion Method

The previously developed Method of Modal Parameters (MoMP) was applied to calculate the Singularity Expansion Method (SEM) poles of the single and double wire segments with symmetrical geometry: straight wire, circular wire and helix wire, which are important for EMC practice. The symmetry leads to the simplification of the corresponding formulas for matrix elements and allows to obtain SEM poles of the first, second and third layers, which correspond both to the known analytical results and numerical data. Moreover, for the first layer of the poles one can use a simplified variant of the method taking into account only diagonal elements of the p.u.l. impedance matrix.

Experimental study on flame spread characteristics of double PE-insulated wires with different spacing distances

In this paper, three types (typeⅠ, type Ⅱand type III) of polyethylene-insulated wires with copper core diameters of 6 mm, 8 mm and 10 mm and thickness of polyethylene of 2 mm respectively, were used to research the flame spread of double wires with spacing sizes of 0 mm,1 mm,2 mm,3 mm,5 mm,7 mm,10 mm,12 mm, 15 mm and 18 mm. The results showed that with the increase of spacing, the flame changed from “less propagating” to “quasi-intermittent merging” stage, to “continuous merging” stage, then to “intermittent merging” stage, and finally to “non-merging” stage. For type III of the largest Cu core diameter, the flame could not spread when s = 1 mm and 2 mm.After that, the same transition from"continuous merging” stage to “non-merging” stage was found. The flame width showed the similar trend with FSR for typeⅠand type Ⅱ, while for type III the correlation between flame width and FSR was not closely related. The mass loss rate and mass dripping rate showed the similar trends with FSR. The faster FSR, the larger mass loss and dripping rates. The “re-burning” phenomena were found during the process of flame spread with small spacing distances, which made the residual material PE ignite again, and the flame width increase.

Double bridle wire technique: A better alternative for mandibular fracture stabilization.

The first documented evidence of splinting teeth to stabilize mandibular fractures dates back to the Greco–Roman period. Bridle wires then, were made of gold/linen threads.[1] The original technique as described by Hippocrates involved placement of a single wire around the teeth adjacent to the fracture, which is followed till date. The technique is a temporary ' first aid' measure aimed at stabilizing the fracture ends by passing a circumdental pre-stretched 26 gauge wire around the necks of one or two teeth on either side of the fracture. Maintaining manual reduction at the alveolus level, the wire ends are twisted and tightened in a clockwise manner to attain stability. This helps alleviate pain due to fracture movement, gives support and protects from further soft tissue damage and muscle cramping.[2] It helps assist in open reduction and internal fixation (ORIF) of mandible fractures by holding the fracture in a reduced position during fixation.[3] Clinically, loosening of the single bridle wires is often noted and can lead to errors in fixation or patient discomfort due to fracture mobility. A double bridle wire technique can provide better stability and maintenance in the reduced position for mandibular fractures. Similar to a single circumdental wire, two wires are passed around one or two teeth adjacent to the fracture site. The operator while maintaining reduction with one hand, tightens one of the wires by pulling it to one direction away from fracture end (similar to a single wire technique). Subsequently, he pulls and tightens the other wire in the opposite direction, again away from the fracture site. Both the wires are equally tightened to maintain minimum force on the fracture site. After equal tightening of both the bridle/tie wires, the twisted ends are cut and turned clockwise to form a small loop so that the buccal gingiva is not damaged [Figures 1 and 2].Figure 1: Fracture before reductionFigure 2: Fracture stabilized with double bridle wiresIn single mandibular fractures this technique can help reinforce stability of the reduction and can sometimes eliminate the need for arch bars. Financial support and sponsorship Nil. Conflicts of interest There are no conflicts of interest.

Towards custom built double core carbon nanothreads using stilbene and pseudo-stilbene type systems.

Until recently, saturated carbon nanothreads were the missing tile in the world of low-dimension carbon nanomaterials. These one-dimensional fully saturated polymers possess superior mechanical properties by combining high tensile strength with flexibility and resilience. They can be obtained by compressing aromatic and heteroaromatic crystals above 15 GPa exploiting the anisotropic stress that can be achieved by the diamond anvil cell technique. Recently, double-core nanothreads were synthesized by compressing azobenzene crystals, achieving the remarkable result of preserving the azo group as a linker of the resulting double thread. Herein, we demonstrate the generality of these findings through the synthesis of double carbon nanothreads from trans stilbene and azobenzene-stilbene mixed crystals. Employment of Fourier transform infrared spectroscopy and synchrotron X-ray diffraction enabled a comprehensive characterization of the reactivity identifying threshold conditions, kinetics and structure-reaction relationship. In particular, the reaction is anticipated by a phase transition characterized by a sudden increase of the monoclinic angle and a collapse along the b axis direction. Large bidimensional crystalline areas extending several tens of nanometers are evidenced by transmission electron microscopy also confirming the monoclinic unit cell derived from X-ray diffraction data in which threads possessing the polymer 1 structure, as suggested by density functional theory calculations, are packed. The most exciting result of this study is the demonstration of viable synthesis of double nanothreads where the number and the nature of chromophoric groups linking the threads can be tuned by preparing starting crystals of desired composition, thanks to the isomorphism typical of the pseudo-stilbene molecules. This is extremely important in tailoring nanothreads with tunable optical properties and an adjustable band gap, also exploiting the possibility of introducing substituents in the phenyl groups.

Impaction Bone Grafting for Severe Femoral Bone Loss: Surgical Technique in Revision Total Hip Arthroplasty.

The specific steps to perform this procedure include (1) preoperative planning; (2) positioning of the patient and surgical approach; (3) cautious removal of the previous components; (4) preparation of the bone graft; (5) implantation of the appropriate IBG revision system, restoring bone loss from distal to proximal and utilizing metal mesh as needed; (6) implantation of the new stem, bypassing the defect; and (7) aftercare with protected weight-bearing in order to avoid subsidence of the stem and periprosthetic fracture. There are several alternatives to the IBG technique in the setting of revision total hip arthroplasty with extensive femoral bone loss. These alternatives include distal cementless fixation (either modular or nonmodular), a megaprosthesis, or an allograft-prosthesis composite. The rationale for use of the IBG technique is restoration of bone stock. Although this issue may be irrelevant in low-demand elderly patients, we believe it is of the utmost importance among young (i.e., <60 years old) and active patients. This technique is versatile enough to be utilized in different scenarios such as periprosthetic fracture, periprosthetic joint infection (2-stage protocols), and aseptic loosening. We have reported favorable clinical and radiographic outcomes for the treatment of both aseptic and septic femoral component loosening. In all cases, we utilized vancomycin-supplemented impacted cancellous allograft without evidence of secondary effects with regard to bone incorporation, nephrotoxicity, or allergic reactions. Although it was initially contraindicated, we further extended the indication for this reconstruction alternative to cases of circumferential proximal bone loss with non-neoplastic bone defects of ≤15 cm, utilizing encompassing metal mesh and a bypassing long stem. Recently, we reported on poorer outcomes following IBG compared with the use of uncemented modular stems for the treatment of type B3 periprosthetic femoral fractures, with a significantly higher rate of infection and implant breakage for the former treatment. Nowadays, we advocate the use of this technique in young, active patients (i.e., <60 years old) with a femoral bone defect Paprosky grade IIIB or IV, in which reconstitution of bone stock is crucial to avoid an eventual implant failure in the long term. This technique requires an experienced team. This procedure should be avoided in the presence of active periprosthetic joint infection.The gluteus maximus tendon should be detached to avoid tensioning the sciatic nerve and to decrease the chance of periprosthetic femoral fracture.Massive bone loss can jeopardize correct implant orientation and restoration of biomechanics. In this scenario, surgeons might consider the intercondylar axis as a guide for femoral version.Try to avoid (if possible) trochanteric or extended trochanteric osteotomy because proximal bone stock is necessary to contain the bone grafts. In some cases, such as those in which the removal of the stem is difficult, especially with certain uncemented stem designs, an extended trochanteric osteotomy must be performed. Whether or not a cemented stem is removed, it is mandatory to remove all remaining cement in the femoral canal.Preoperative templating is a necessity to reconstruct leg length. Accurately determining the length of the mesh is the most important step to avoid shortening or overlengthening of the lower extremity.Approximately 10 cm of circumferential metal mesh should be fixed with 3 to 5 double cerclage metal wires to the remaining bone. The new femoral stem should bypass extend beyond the mesh for approximately 5 cm. If the stem does not bypass the mesh, there is an increased risk of postoperative fracture.In order to decrease the risk of intraoperative femoral fracture, the distal aspect of the femur should be secured with cerclage wires, and the proximal aspect of the femur should also be protected with cerclage wires over the mesh. As in any other complex femoral revision procedure, torsional forces in the supracondylar zone should be avoided, especially during trial or stem reduction maneuvers.Always utilize a bone graft mixed with antibiotic powder.Retrograde cementation must be done with cement that is in a more liquid state than in primary total hip arthroplasty. PO = postoperativePMMA = polymethyl methacrylateIV = intravenousLMWH = low molecular weight heparinDVT/EP = deep vein thrombosis and extended prophylaxis.

Direction dependency in coaxial laser double wire Direct Energy Deposition

Coaxial Laser wire Direct Energy Deposition (L-DED) promises a direction-independent buildup due to a centric supply of the welding material. To fabricate Functionally Graded Materials (FGMs), a processing head was designed that is capable of supplying two wire materials into the processing zone. This study investigates the direction dependency of welding seams produced by two 1.4718 metal wires with a diameter of 0.8 mm in a coaxial laser setup using three separately controllable single laser beams with a maximum combined laser power of 660 W. The welding wires are supplied simultaneously to the laser spot under an incidence angle of 3.5° to the middle axis of the processing head. The seam geometry is investigated using a confocal laserscanning-microscope. A comparison of the height, width and macroscopic seam geometry reveals the influence of the welding direction on the seam geometry and quality in Laser Double wire Direct Energy Deposition (LD-DED).

Influence of laser spot oscillation parameters on the seam geometry and dilution in the LDNA process

The “Laser-assisted double wire with non-transferred arc surfacing process (LDNA)” is characterized by an electric arc burning between the filling wires. The molten filler material is fed to the substrate surface by gravity and is shaped by a laser beam. In this work, the influence of laser parameters on seam geometry and dilution is investigated. The investigations include a linear and convex pendulum form, a focal length of 300 mm and 400 mm, an oscillation frequency of 10 Hz and a disc laser using a wavelength of 1,030 nm with a power of 1,000 W and 1,400 W. Two 316L filling wires with 1.2 mm and an AISI1024 substrate with 20 mm are used. The change in the dilution and the welding geometry is determined.

Characterization of Nickel-Titanium Alloy Graded Materials Using Double Wire Alternating Current Cross Arc Addictive Manufacturing

Characterization of Nickel-Titanium Alloy Graded Materials Using Double Wire Alternating Current Cross Arc Addictive Manufacturing

Hammertoe Correction with Wire Fixation of Varying Length

Category:Midfoot/Forefoot; Lesser ToesIntroduction/Purpose:Hammertoe deformities are commonly encountered and frequently require surgical intervention for pain relief and shoewear accommodation. Various techniques exist for surgical management, but proximal interphalangeal (PIP) joint fusion with Kirschner (K) -wire fixation remains an inexpensive, popular treatment. The decision to place a K wire that spans the metatarsophalangeal (MTP) joint versus only fixating the digit through the proximal phalanx is entirely dependent on provider preference and situational context. This study was performed to evaluate the effect of length of wire fixation on clinical outcomes after hammertoe reconstruction.Methods:A retrospective review of all hammertoe reconstructions by a single fellowship trained foot and ankle surgeon from 2017-2021 was performed. Hammertoe reconstructions involved PIP arthrodesis with double wire fixation and other supplemental balancing procedures as indicated. Pins were routinely removed at between 5-6 weeks and protected heel weightbearing was generally advised. Wire length was chosen at the discretion of the surgeon intraoperatively. Patients were excluded if no radiographic follow-up was available after pin removal. Patient outcomes were evaluated with radiographs and clinic notes to assess pin length, pin complications/breakage, return to the OR, MTP congruency, and PIP union rate. A logistic regression was performed to determine the odds ratio for digit congruency and non-union status.Results:88 toes (45 patients) underwent hammertoe reconstruction with K wire fixation. Of these toes, 47 had wires that spanned the MTP and 41 that did not. There were 65 congruent MTP joints and 23 incongruent joints. 16 of the incongruent joints were pinned across the MTP while 31 in the congruent group were pinned. One toe in the MTP group required return to the OR for removal of a broken wire, compared to zero in the phalanx group (p=1.0). No pins broke in the phalanx group, compared to 3 in the MTP group (p=0.25). One toe in the proximal phalanx group had their pins pull out early but no return to the OR was needed. There were 26 (63.4%) PIP radiographic nonunions, compared to 21 (44.7%) in the MTP group (p=0.12).Conclusion:Wire failure was a rare occurrence in either group. Breakage only occurred in the MTP group, but only required one surgical intervention for removal. Pinning the MTP may allow for improved deformity correction and increased stability of the hammertoe reconstruction. Pin breakage can occur, but it may be of little clinical significance. The increased stability and control of MTP correction may be worth the potential risk of pin breakage. Pin breakage may be avoided potentially by using thicker wires, earlier removal, and protected weightbearing.

Complication after the reconstruction of the old patellar tendon rupture

Introduction. Chronic patellar tendon rupture (PTR) occurs rarely; its frequency and prevalence are unknown. There are very little data on the late patellar tendon reconstruction in rheumatoid arthritis and its complications. Case report. We presented a surgical repair of a PTR with early postoperative rupture of the contralateral patellar tendon for a 21-year-old woman with a past medical history of juvenile rheumatoid arthritis (treated with corticosteroids) who sustained initial injury 11 months prior to the presentation. The contralateral side was used for autograft harvesting. We used bone-tendon-bone (BTB) autograft and allografts followed by double-wire loop reinforcement and immediate postoperative mobilization. The patient was followed for 2 years, and the function of both knees was re-stored completely, with a full active range of motion. In this case, reconstruction of an 11-month-old chronic PTR (with complete resorption of the tendon and completely separated infrapatellar pads, complicated by the contralateral PTR) with BTB autograft and allografts and double wire loop reinforcement gave an excellent functional result. Two years after the surgical treatment, the extensor function of both knees was completely restored with a full range of movements. The patient reported satisfying outcomes and was able to return to all pre-injury activities without the assistance of orthopedic devices. Conclusion. This case report highlights the importance of the early diagnosis and describes operative techniques used in chronic PTR repair and treatments of the early postoperative complications such as rupture of the contralateral tendon.