Open Treatment Research Articles

Energy mechanism of gas channeling channels in complex fracture networks for CO2 injection in ultra-low permeability reservoirs

The injection of CO2 into ultra-low permeability can enhance production as well as accomplish storage of carbon. However, the gas channeling phenomenon is serious and there is a lack of explanation of the energy mechanism. Based on the current state of CO2 gas channeling in the Y29-105 well group located in the Huang 3 block of Jiyuan Oilfield, this study utilises the ABAQUS finite element cohesion model to explore the mechanical evolution of the CO2 channel expansion process. And according to the size of the cross-flow channel, intra-fracture pressure, damage displacement and expansion pressure, it is divided into the unconnected stage, the inter-well connected stage and the well group connected stage. Furthermore, we also established energy judgment criteria for the expansion behaviour of gas channeling channels, including stopping at natural fractures, extending along natural fractures, and directly crossing natural fractures. Upon comparison with theoretical and experimental results, it was determined that the energy discrimination criterion is appropriate for expansion along natural fractures and cross natural fractures. It can be seen that our research results can offer energy mechanism support for preventing, controlling, and predicting large-scale CO2 injection in ultra-low permeability reservoirs.

Ranking the Orthopedic Procedures With the Highest Morbidity and Mortality.

Musculoskeletal conditions currently affect more than one-third of the US population and orthopedic procedures play a pivotal role in managing them. Like any invasive intervention, these carry a wide spectrum of risk, necessitating a comprehensive understanding of the associated morbidity and mortality. This study sought to provide a global perspective of the risks and complications associated with these procedures to establish an easy to understand risk stratification tool for both patients and providers. Current Procedural Terminology codes associated with orthopedic surgery were identified in the American College of Surgeons National Surgical Quality Improvement Program database from 2018 to 2020. Each code was associated with its rate of 30-day mortality as well as any adverse event (AAE) and then ranked for descriptive analysis. In total, there were 698,549 patients who underwent orthopedic procedures associated with 94 CPT codes with at least 1 morbidity event and 144 CPT codes with at least 1 AAE. The CPT code associated with the highest mortality was 27590 or above knee amputation. The CPT code associated with the highest rate of AAE was 27507 or open treatment of femoral shaft fracture with plate and screws. This is the first study to compare the rates of morbidity and mortality in all patients with orthopedic procedures. There was a strong bias toward increased risk associated with lower extremity surgery and surgery most often performed in the geriatric population. [Orthopedics. 202x;4x(x):xx-xx.].

Study on the evaluation of shale reservoir brittleness based on mineral disorder

Brittleness serves as a critical indicator for assessing whether reservoirs can form complex fracture networks. While methods based on brittle mineral content or rock mechanical parameters are widely used, their lack of integration between mineralogy and mechanics introduces limitations. A single evaluation parameter cannot accurately assess shale brittleness. There is a need for a universally applicable method that comprehensively considers mineral composition, mechanical properties, and brittleness variations in shale evaluation. This study uses Longmaxi shale in the Sichuan Basin as an example, establishing a mineral disorder index based on shale mineral composition and mechanical characteristics, incorporating the influence of confining pressure to establish a shale brittleness index. Results indicate varying weights of brittleness contributions from different minerals, ranked in descending order: pyrite, quartz, calcite, dolomite, feldspar, and clay. Greater complexity in mineral combinations correlates with lower shale brittleness indices. Typically, single mineral disorder indices show a positive correlation with internal mineral disorder indices. Confining pressure exhibits an inversely proportional relationship with shale brittleness indices, with brittleness at 30, 50, and 70 MPa confining pressures being 0.737, 0.586, and 0.451 times those without confining pressure, respectively. This method guides current brittleness research and reservoir production enhancement.

A clinical prospective study on the surgical management of zygomatico-maxillary complex fractures using two-point fixation

The ZMC fractures are one of the most frequently occurring maxillofacial injuries due to its prominence and facial contour. The ZMC forms a principle buttress of face and helps transmit occlusal forces to skull base. Fracture of zygomatic bone leads aesthetic and functional deformity. Restoration to premorbid condition is most predictable by ORIF. In this study was to evaluate efficacy of two-point internal fixation using conventional miniplates and screws for ZMC fractures. 35 patients with established unilateral isolated ZMC fractures were operated using two-point fixation method i.e. the maxillary buttress and the fronto-zygomatic suture, followed up for 3 months. Patients were assessed clinically and radiographically at different follow up intervals. Charts of patients were reviewed for age, gender, etiology, malar height analysis and vertical dystopia. 35 patients in this study, underwent ORIF under GA with two-point fixation. Preoperatively, mean malar height of the patients recorded was 66.55 ± 3.02. There was a significant increase in malar height postoperatively (P < 0.0001). 70.24 ± 2.05, at 1st week, and 69.87 ± 1.98. in 3rd and 6th weeks. Preoperatively, mean vertical dystopia of patients was 2.24 ± 0.71. Postoperative resolution of vertical dystopia was statistically significant (P<0.0001), with value of 0.52 ± 0.52.Integrity of ZMC is important in maintenance of normal facial width and prominence of cheek. Two‑point fixation shows satisfactory results functionally, esthetically and also provides additional advantage by eliminating another surgical site. Thus we conclude that our study provides a basis for further research.

Adaptive PF-CZM for multiphysics fracture analysis in functionally graded materials

Functionally graded materials (FGM) hold significant relevance in engineering due to their tailored material property gradation, designed for specific engineering applications. The challenge in fracture analysis of FGM stems from the spatial variation of material properties, which complicates the prediction of crack topology. Local and global refinement strategies are impractical for fracture analysis in FGM due to the unpredictable nature of crack topology, which renders local refinement infeasible. Additionally, global refinement is not advisable as it leads to a significant increase in degrees of freedom, adversely affecting computational efficiency.The novelty of this research lies in the incorporation of spatial variation in both the length scale and material properties, enhancing the realism of FGM domain modeling. To preserve the required length scale, it is necessary to adopt a minimum mesh size, which consequently results in a substantial increase in the degrees of freedom and, thereby, escalates the computational cost. To address these challenges, the study employs an adaptive mesh refinement (AMR) algorithm integrated with a phase-field cohesive zone model (PF-CZM), providing a robust solution for accurate fracture analysis in FGM. Based on the ideas stemming from the need for efficient and realistic modeling, the AMR-PF-CZM framework refines the mesh efficiently in regions of crack growth based on crack-driving energy and phase field variable, thereby eliminating the need for pre-refinement. The findings demonstrate a 76%–85% increase in computational efficiency and accuracy of the AMR-PF-CZM approach compared to the non-adaptive PF-CZM. Furthermore, the developed algorithm’s applicability to dynamic fracture and multi-physics problems, specifically addressing mechanical and thermal fracture in FGM, underscores the importance of this approach in capturing complex fracture phenomena.

Numerical simulation of hydraulic fracture propagation from recompletion in refracturing with dynamic stress modeling

Owing to the rapid decline of oil production from tight oil reservoirs after primary hydraulic fracturing treatment on the horizontal well, a refracturing stimulation is proposed for tight oil recovery. In this study, a fully coupled dynamic stress computational method with a finite-element method is presented, and depletion-induced dynamic stress is simulated by coupled numerical modeling. In addition, the extended finite-element method (XFEM) approach is used to investigate the effect of different parameters on fracture dynamic propagation in recompletion from refracturing. The results highlight the effects of production-induced stress changes following hydraulic fracture propagation. When multiple fractures are stimulated simultaneously from recompletion during refracturing, curved fractures are commonly observed, and the deflected fractures generally divert toward the primary stimulated area with low pore pressure. The results indicate that comprehensive factors can affect the hydraulic fractures propagation from recompletion. The optimal refracturing time window can be determined using the dynamic stress condition and stimulated area. The initial completion spacing, initial fracture length, and recompletion perforation cluster spacing can also affect the fracture geometry from the recompletion. A larger initial fracture length can induce a larger stress change area, whereas a larger distance between the new perforations in recompletion and the old perforations can decrease the depletion-induced stress effect. A high horizontal stress contrast can increase the depletion-induced stress effect because a long fracture extends the area. Owing to the nonuniform pressure and stress distributions, more nonuniform fractures are commonly generated in the refracturing treatment. Thus, temporary plugging injection and proppant inertia must be designed while reducing the number of perforations near the initial perforation positions. This can help decrease the possibility of strong curved fractures and screen out problems.

Study of the fracture propagation and the corresponding heat mining performance of multi-branch radial wells geothermal system based on the THM-D coupling model

Due to the multi-well enhanced geothermal systems can significantly improve the heat transfer efficiency and the multi-branch radial well geothermal system can reduce the well construction cost, it is necessary to investigate the fracture propagation and the heat mining performance of the multi-branch radial well geothermal system. Based on the constructed THM-D coupling model, the fracture propagation rules of multi-branch radial wells under the co-function of low-temperature induced thermal stress and radial well induced stress is explored. Then the heat mining prediction study during the heat extraction stage is conducted based on the generated fracture. Furthermore, the influence of radial well characteristic parameters on fracture propagation and the corresponding heat mining performance of multi-branch radial well geothermal system is discussed. The results show that the smaller radial well angle in multi-branch radial well system can generate a larger scope of fracture network between the included angle under the co-function of radial well induced stress and low-temperature induced thermal stress, which will correspond to a larger heat extraction scope in heat mining stage. When the radial well included angle along the direction of maximum horizontal in-situ stress is 120°, the fracture network obtained by fracturing is the most complex. Excessive branching of radial wells can lead to significant induced stress in the plane of radial wells, which will affect the propagation of the fracture network in the direction of longitudinal connection between the doublet wells, thereby affecting the corresponding heat mining performance. With the increase of radial well length, the ability to induce the formation of branching fractures raises, resulting in more complex fracture network. In the heat mining stage of 10-year development, the outlet temperature and heat mining rate respectively increased by 5.83% and 6.9% when the radial well length is 75 m compared to 50 m.

Summary of Research: Ten-Year Safety and Clinical Benefit from Open-Label Etanercept Treatment in Children and Young Adults with Juvenile Idiopathic Arthritis.

This is a summary of the original article 'Ten-year safety and clinical benefit from open label etanercept treatment in children and young adults with juvenile idiopathic arthritis'. Juvenile idiopathic arthritis (JIA) usually appears before the age of 16. JIA causes pain, swelling, and stiffness in the joints. People with JIA receive treatment for several years until the disease goes into prolonged remission. Therefore, the long-term safety of these treatments is an important topic. Etanercept is a treatment for JIA, which acts on the body's immune system to reduce arthritis. This summary of research article describes safety and how well etanercept works in children with JIA taking it for up to 10years.

Foliar Uptake and Distribution of Metallic Oxide Nanoparticles in Maize (Zea mays L.) Leaf.

The foliar uptake of Fe3O4, Cr2O3, CuO, and ZnO nanoparticles (NPs) by maize (Zea mays L.) was studied in a lab-scale experiment. The significant increase of Fe concentrations in leaves exposed to Fe3O4 was observed in both stomatal closing and stomatal opening treatments, suggesting the presence of a nonstomatal uptake. In parallel treatments with equal doses of Fe3O4 (∼200 nm), Cr2O3 (∼300 nm), CuO (∼30 nm), and ZnO (∼40 nm) (20-200 μg), the retention percentage of Fe in the leaves (21.0-69.0%) was higher than that of Cr, Cu, and Zn (0.5-14.0%). The steric hindrance effect seems more important for NPs of >200 nm, while hydrophobic surface and negative charge promote the foliar uptake of NPs smaller than 200 nm. The accumulation of NPs in the cuticle was observed through dark-field hyperspectral microscopy. Cr2O3, Fe3O4, and CuO NPs were difficult to penetrate the cuticle. In comparison, ZnO further migrated and distributed within the extracellular space of epidermal and mesophyll cells of the exposed leaf, possibly due to its comparatively higher solubility and hydrophilicity. The findings highlight the potential of the nonstomatal uptake, which might be a critical route for metallic oxide NPs to enter the food chain.

Numerical simulation study of fracture propagation by internal plugging hydraulic fracturing

Internal temporary plugging fracturing technology improves the stimulated volume by forming a more complex fracture network, significantly enhancing the reservoir stimulation effect and effectively developing unconventional oil and gas resources. However, the current understanding of the fracture propagation mechanism on internal temporary plugging fracturing is still unclear, making it difficult to determine the main controlling factors that affect the shape of the fractures. In addition, the lack of practical numerical simulation methods for temporary plugging fracturing makes it challenging to provide guidance for field scheme design. Utilizing the finite element cohesive zone method, which incorporates globally embedded cohesive elements, this study constructs a comprehensive numerical model to investigate the propagation behavior of temporarily plugging fracturing fractures. The model delves into the impact of various geological and construction parameters on the opening conditions of branch fractures during the temporary plugging fracturing process, as well as the propagation patterns of fractures within naturally fractured reservoirs. The research findings indicate that the construction factors have the following impacts: When the pumping rate and viscosity of the fracturing fluid are comparatively high, the resulting fluid pressure within the fracture escalates, resulting in the creation of numerous branch fractures within the naturally fractured reservoir. This, in turn, augments the fracture’s complexity. However, these two factors have little influence on the maximum deflection distance of the deflected fracture. As for the geological factors, an increase in the horizontal stress difference will decrease the maximum deflection distance of the deflected fracture, reducing the number of natural fractures intersected and shortening the length of the deflected fracture. Conversely, an increase in the approach angle will increase the maximum deflection distance of the deflected fracture, thereby expanding the affected area. Additionally, the influence of Young’s modulus and Poisson’s ratio on fracture propagation is very slight. A decrease in the tensile strength of natural fractures leads to more natural fractures being intersected during the process, resulting in increasing the length of the fracture and an improvement in the complexity of the fracture grid.

Rare legumes are missing mutualists, but herbivory and environmental filtering are more important determinants of reintroduction success

Soil microbial mutualists like rhizobia bacteria can promote the establishment of rare, late‐successional legumes. Despite restoration efforts, these mutualists are often absent in the microbiome. Therefore, restoring this mutualism by directly inoculating rare legumes with rhizobia mutualists may increase plant establishment. We inoculated seedlings of Amorpha canescens, Dalea purpurea, and Lespedeza capitata with three strains of species‐specific rhizobia each to investigate how this mutualism would promote growth in the field and in the greenhouse. Because many herbaceous plants are vulnerable to herbivory, we used exclosures for half of our field transplantations to prevent mammalian herbivory. We did not find that rhizobia bacteria directly promoted the growth of our legumes in the field but rather that herbivory and environmental conditions overwhelmed the effects of the rhizobia. Of the plants transplanted, only 17.78% of 180 survived to the end of the growing season, all of which were protected from herbivory. Survival at the end of the growing season was also greater in the northern, drier end of the field site. In the second growing season, plants were more likely to survive in the exclosure treatment, while only four recovered in the open treatment. In the greenhouse, we found increased nodulation with inoculations, supporting the hypothesis that species‐specific mutualists are absent from restoration sites. Though several recent studies have shown that restoring mutualistic interactions has the potential to dramatically improve the outcomes of ecological restoration, our results show that protecting rare species from herbivory after transplantation might achieve greater gains in establishment.

Learning CO[formula omitted] plume migration in faulted reservoirs with Graph Neural Networks

Deep-learning-based surrogate models provide an efficient complement to numerical simulations for subsurface flow problems such as CO2 geological storage. Accurately capturing the impact of faults on CO2 plume migration remains a challenge for many existing deep learning surrogate models based on Convolutional Neural Networks (CNNs) or Neural Operators. We address this challenge with a graph-based neural model leveraging recent developments in the field of Graph Neural Networks (GNNs). Our model combines graph-based convolution Long-Short-Term-Memory (GConvLSTM) with a one-step GNN model, MeshGraphNet (MGN), to operate on complex unstructured meshes and limit temporal error accumulation. We demonstrate that our approach can accurately predict the temporal evolution of gas saturation and pore pressure in a synthetic reservoir with impermeable faults. Our results exhibit a better accuracy and a reduced temporal error accumulation compared to the standard MGN model. We also show the excellent generalizability of our algorithm to mesh configurations, boundary conditions, and heterogeneous permeability fields not included in the training set. This work highlights the potential of GNN-based methods to accurately and rapidly model subsurface flow with complex faults and fractures.

The relationship between intraoperative surrogates of vascular stiffness, cerebral aneurysms, and surgical outcomes

ObjectiveIncreased arterial stiffness has been linked to aneurysm formation in the systemic and cerebral circulations, though the role played by arterial stiffness in the cerebral vasculature continues to be refined. This study assesses whether intraoperative surrogates of arterial stiffness differ between patients with cerebral aneurysms and controls, and the extend that these indices relate to outcomes following open surgical treatment. MethodsWe evaluated patients in a prospectively maintained database who underwent cerebral aneurysm surgery, and compared them to controls without cerebral aneurysms. Arterial stiffness was estimated using the intraoperative ambulatory arterial stiffness index (AASI) and average pulse pressure (PP). ResultsWe analyzed 214 cerebral aneurysm patients and 234 controls. Patients in the aneurysm group were predominantly female and had a higher incidence of hypertension, diabetes mellitus, and vascular disease. They also demonstrate elevated AASI and average PP. When stratified by the occurrence of subarachnoid hemorrhage (SAH) or unfavorable neurological outcome, the AASI and average PP were not highly associated with the occurrence of SAH but were highly associated with unfavorable neurological outcomes. After multivariable analysis, both the AASI and average PP were no longer associated with unfavorable neurological outcomes, however elevated age, strongly linked with arterial stiffness, became a key predictive variable. ConclusionReadily obtained intraoperative surrogates of arterial stiffening demonstrates its presence in those with cerebral aneurysm disease and the extent that it does it may meaningfully direct their clinical course. However, multivariable analysis demonstrates limitations of using arterial stiffness measures to predict clinical outcomes.

Clinical and functional outcomes of locked plating vs. cerclage compression wiring for AO type C patellar fractures– a retrospective single-center cohort study

Abstract Purpose Although “tension-band wiring” is still commonly used to stabilize patellar fractures, the technique has recently been scrutinized due to biomechanical insufficiency. Consequently, the AO Foundation renamed the principle to compression cerclage wiring (CCW). Several studies propose favorable outcomes when utilizing locked plating (LP). This study aims to compare outcome of CCW and LP for complex patellar fractures. Methods A retrospective, single-center cohort study was performed on patients who underwent operative treatment for (AO 34 C-Type) patellar fractures between April 2013 and March 2023. Patients with a 12 month follow up were included. We grouped and compared patients based on the applied treatment strategy: group LP vs. group CCW. Primary outcome parameters included implant-related complications and revision surgeries. Secondary outcomes were length of stay, return to work and 12 months functional outcome (Lysholm score). Odd ratios for complications and revisions were calculated using the conditional Maximum Likelihood Estimate. The threshold for statistical significance was set at p < 0.05. Results Of 145 patients, 63 could be included (group LP: n = 23 and group CCW: n = 40). Fractures in group LP were significantly more complex in regard to AO Classification (p < 0.001), number of fragments (p < 0.001) and degree of comminution (p < 0.001), yet odds of complications were significantly lower in group LP (OR: 0.147; 95%CI: 0.015–0.742; p = 0.009). K-wire migration was the most common complication in group CCW (20%). Odds of revision surgery were significantly lower in group LP (OR: 0.000; 95%CI: 0.000-1.120; p = 0.041). The average Lysholm score at one year was favorable in both groups (89.8; SD: 11.9 in group LP and 90.6; SD: 9.3 in group CCW; n.s.). Conclusion In our study cohort, LP was routinely chosen for more complex fracture morphologies; nevertheless the data implies that LP may be considered as the superior fixation technique in regard to complications and revision operations. Especially, K-wire migration occurs frequently after CCW. The one year functional outcome was comparable between the groups, with both demonstrating good results. Prospective randomized studies are indicated to validate our findings.

Data-driven multiscale geomechanical modeling of unconventional shale gas reservoirs: a case study of Duvernay Formation, Alberta, West Canadian Basin

The Duvernay Formation in Canada is one of the major oil and gas source formations in the Western Canadian Sedimentary Basin, located at its deepest point. While it demonstrates promising development potential, challenges arise in the urgent need for integration of geology and engineering models, as well as in optimizing sweet spots, particularly as infill wells and pads become central operational objectives for the shale gas field. A lack of the geomechanical understanding of shale gas reservoirs presents a significant obstacle in addressing these challenges. To overcome this, we implemented data acquisition and prepared historical models and profiles, resulting in an extended high-resolution geological and reservoir property model with a fine grid system. Subsequently, a 3D full-field multi-scale geomechanical model was constructed for the main district by integrating seismic data (100 m), geological structures (km), routine logs (m), core data (cm), and borehole imaging (0.25 m), following a well-designed workflow. The predicted fracturability index (brittleness) ranges from 0.6 to 0.78, and a lower horizontal stress difference (STDIFF) is anticipated in the target formation, Upper Duvernay_D, making it a favorable candidate for hydraulic fracturing treatment. Post-analysis of the multi-disciplinary models and various data types provides guidelines for establishing a specific big database, which serves as the foundation for production performance analysis and aggregate sweet spot analysis. Fourteen geological and geomechanical candidate parameters are selected for the subsequent sweet spot analysis. This study highlights the effectiveness of multi-scale geomechanical modeling as a tool for the integration of multi-disciplinary data sources, providing a bridge between geological understanding and future field development decisions. The workflows also offer a data-driven framework for selecting parameters for sweet spot analysis and production dynamic analysis.

Virtual surgical planning in tripod zygomatico-maxillary complex fractures: A prospective comparison between two different strategies

Multifragmentary and displaced zygomaticomaxillary complex (ZMC) fractures are often a challenge for the maxillofacial surgeon. The aim of this study was to evaluate the improved performance in the management of patients with tripod fracture of the orbito-zygomaticomaxillary complex, using two different methods of virtual surgical planning — virtual reduction and mirroring — compared with traditional management. A cohort of 60 patients was selected and divided into three groups, each consisting of 20 individuals. Patients in the first group were managed using the virtual reduction method, those in the second group using the mirroring method, and those in the third group using a traditional surgical approach. Having achieved virtual fracture reduction, a stereolithographic model was printed, on which preplating of the plates was performed. The results showed that virtual reduction was the most accurate in absolute terms, with a mean discrepancy in juxtaposition of the preoperative and postoperative CT images of 0.175 mm (SD ± 0.147), compared with 0.403 (SD ± 0.166) for the mirror method (and traditional method (0.875, SD ± 0.112; p > 0.0001). The average surgical time for virtual reduction (89.5 min) was faster than for mirroring (94.25 min) and for the traditional approach (96.75 min). In conclusion, the use of virtual surgical planning allows greater intraoperative accuracy, reduced surgical time, and reduced postoperative complications compared with traditional surgery. Of the two methods, virtual reduction performed best for the outcomes decribed.

Clinical outcome of surgically treated displaced acetabular fractures with central dislocation using combined anterior and medial plating

<p><strong>Aim </strong>Acetabular fractures are complex articular fractures with a big challenge for orthopaedic surgeons. Surgically managed displaced fractures carry favorable outcomes, especially if the articular surface is reduced accurately. This study aims to assess the clinical outcomes of surgical-ly fixed displaced acetabular fractures with central dislocation using combined anterior and medial plating.<br /><strong>Methods </strong>We have retrospectively evaluated sixteen patients, who had surgically managed dis-placed acetabular fractures with central dislocation at our institute. All patients underwent open reduction and internal fixation using combined anterior and medial plating via the Kocher-Langenbeck, the ilioinguinal, or the Stoppa approach. The functional outcome was assessed using the Harris Hip score.<br /><strong>Results </strong>Our study includes sixteen patients (12 males, 4 females) with a mean age of 35 years (range: 15-53 years). The mean follow-up was 7.8 years (range: 5-13 years). Functional outcomes were good to excellent in 12 (80%) patients and fair in 3 (20%) patients. At the final follow-up, the solid union had been achieved in all fractures, the mean HHS was 88.84 ± 7.61.<br /><strong>Conclusion </strong>Early reduction and surgical fixation of dis-placed acetabular fractures with central dislocation using combined anterior and medial plates appear to have good clinical outcomes.</p>

Clinical and radiological outcome of extended lateral approach via epicondyle osteotomy in complex lateral tibia plateau fractures involving the central and postero-lateral segments

IntroductionThe purpose of this study was to evaluate the clinical and radiological results of complex lateral tibial plateau fractures involving the central segments of the lateral tibial plateau. It was hypothesized that an extended lateral approach by using the lateral epicondyle osteotomy improves the rate of malreduction and yields to good and excellent clinical results at a mid-term follow-up. MethodsThis retrospective case series conducted at two centers evaluated complex lateral tibial plateau fractures treated with an extended lateral approach by lateral epicondyle osteotomy. Fractures were classified according to the AO/OTA and 10-segment classification, with only B/C type fractures involving the antero-latero-central (ALC) and postero-latero-central (PLC)/postero-latero-lateral (PLL) segments. Postoperative computer tomography scans were used to assess the quality of reduction. Clinical outcomes and postoperative complications were evaluated with a minimum follow-up of 2 years. ResultsSixty-five patients (mean age: 47.7 ± 11.5 years) were included, with an average follow-up of 51.9 ± 3.6 months. Radiological outcomes revealed a postoperative fracture step at the ALC/PLC crossing of 0.8 ± 1.1 mm, at the PLC/PLL crossing of 0.4 ± 1.1 mm, and a fracture gap of 1.8 ± 4.0 mm, yielding a Rasmussen Score of 15.1 ± 3.2. No significant differences among type B and C fractures were identified. No case of nonunion of the lateral epicondyle osteotomy was recorded. The mean Knee injury and Osteoarthritis Outcome Score was 80.4 ± 16.2 (type B 85.6 ± 11.9 vs. type C 76.1 ± 18.4, p < 0.05), Lysholm score was 83.4 ± 17.1 (B 89 ± 11.3 vs. C 78.7 ± 20.1, p < 0.05) and International Knee Documentation Committee score was 69.9 ± 18.8 (type B 76.5 ± 15.7 vs. type C 64.3 ± 20.1, p < 0.05). Early complication rate requiring surgical revision due to malreduction or infection were 7 %. None of the patients reported about subjective lateral knee instability at the time of clinical follow-up. ConclusionThe extended lateral approach with lateral epicondyle osteotomy demonstrated excellent radiological alignment and favorable mid-term clinical outcomes. An overall low complication rate was recorded. Notably, long-term revisions due to lateral instability were absent, indicating the safety and efficacy of lateral epicondyle osteotomy as an operative technique.

An improved phase-field model for oil–water two-phase flow and mixed-mode fracture propagation in hydraulic fracturing

An improved novel phase-field model is proposed for describing fracture propagation, effectively characterizing the interactions between oil–water two-phase fluids and solids as well as mixed-mode fracturing. This model encompasses equations for two-phase flow stress balance, fluid flow, and a complex mode fracture phase-field specific to two-phase flow. Within the fluid flow equations, the capillary pressure caused by the oil–water interface during the fluid loss process in the matrix is accounted for, and the anisotropic relative permeability during fluid flow is linked to normalized saturation. The driving forces for fracture propagation in the phase-field are categorized into Mode I and Mode II forces, with the contribution from the oil–water two-phase fluid attributed to the Mode I (tensile) driving force. The model uses finite element numerical discretization and the Newton-Raphson iterative method to establish a numerical iteration format, employing an implicit-explicit staggered solution scheme. Additionally, the model is used to investigate several key factors. It assesses the impact of different intersection angles on fracture propagation in naturally porous media. It also studies the effect of different natural fracture permeabilities on hydraulic fracture propagation. Finally, the model analyzes the propagation patterns of hydraulic fractures under different perforation phase angles.

Are zygomatic implants an alternative to orthognathic surgery in the treatment of a vertical discrepancy ? A case series to describe an open bite treatment protocol

IntroductionThis report aims to present case series to describe a treatment protocol for correction of severe open bite in non-growing patients MethodologyPatients diagnosed with skeletal open bite malocclusion (overbite range: -3 to -6 mm) were treated using a bonded appliance and skeletal anchorage. Intrusive force was applied between buccal bars of appliance and zygomatic multipurpose implants (MPI). Intrusion was continued until positive overbite occurred. Treatment progressed with conventional fixed orthodontic treatment for alignment and settling. MPIs were retained until the end of treatment for retention of intrusion ResultsClinically effective open bite correction was achieved by intrusion of maxillary buccal segment and mandibular counterclockwise autorotation ConclusionThis protocol includes zygomatic anchorage and an appliance that aims triple intrusion effect through combination of orthodontic and physiological forces. Achieving significant maxillary intrusion, controlling mandibular eruption and maximizing mandibular counterclockwise autorotation are the main outcomes of this protocol.