Segmental Fractures Research Articles

Subpixel segmentation of borehole fractures from low resolution Doppler ultrasound images using machine learning

Ultrasonic imaging is utilized in oil and gas, and geothermal boreholes using various logging tools. The imaging resolution of these tools is physically limited by the point spread function (PSF) of the imaging system. It is of interest to be able to accurately resolve features that are blurred out due to the PSF limit. This work evaluates a convolutional neural network (CNN), adapted from medical ultrasound imaging, to obtain subpixel estimates of fracture shape and area in boreholes from ultrasonic power Doppler images. The CNN was trained using a dataset generated using simplified ultrasonic simulations, ignoring effects due to fluid dynamics. The performance of the CNN model was tested on experimental scans obtained using a laboratory setup using a water based drilling mud. The CNN was able to estimate the fracture areas with a significantly lower mean absolute error of 5.0±3.9mm2, compared to 22.9±1.7mm2 using the conventional thresholding method. The CNN also enabled the estimation of fracture shape and area using a single frame of the power Doppler image, compared to about 30 frames required for the thresholding method, facilitating a possible increase in scanning speed of the logging tool. Although, the CNN in this work is applied on power Doppler images from borehole fractures, the model can be easily adapted for similar other applications, such as ultrasonic pulse-echo imaging of boreholes, cement bond evaluation, perforation evaluation in production logging, etc.

Evaluation of Zygomaticomaxillary Complex Fractures with Gillies Approach in Al-Baha Region of Saudi Arabia: A Cohort Study.

The aim of this study was to evaluate the accuracy of the degree of fracture reduction after open reduction and internal fixation of Zygomaticomaxillary Complex (ZMC) fractures in the Saudi population of the Al-Baha region, using Gillies approach. Further comparison with preoperative and postoperative standardized computed tomography (CT) views with the calculation of residual deformity percentage, which remained after the ZMC rehabilitation. A 5-year retrospective CT-based study on preoperative and postoperative axial CT scans of 46 male patients with ZMC fractures. The CT measurements were made (in millimeters) at the fracture site of maximum displacement through the anterior orbital rim and orbital floor, posterolateral wall of the maxillary sinus, zygomatic arch, and zygomaticofrontal suture. For the zygomatic arch, measurements were made (in mm) by drawing a tangent to the fractured arch segments and dropping a perpendicular to the inward displaced fractured arch. The total difference in all measured parts between preoperative and postoperative displacement was calculated in percentages. Upon comparison of preoperative and postoperative zygomaticomaxillary complex CTs, three-point fixation at the regions of infraorbital rim, frontozygomatic suture, and posterolateral wall of the maxilla results in a reduction of the fracture sites in the range of 72.85% to 85%. Maximum reduction was noted at the zygomatic arch, that is, 85%, and minimum at the infraorbital rim, that is, 72.85%. The reduction obtained at all four sites was statistically significant, with P values ranging from .011 to .039. Gillies temporal approach and three-point fixation at the regions of the infraorbital rim, frontozygomatic suture, and posterolateral wall of the maxilla results in satisfactory treatment of ZMC fractures and improves patients oral health and quality of life.

A Case Report of Fracture of the Segment of Maxillary Alveolar Process Involving Primary Incisors

ABSTRACT Traumatic dental injuries (TDIs) have significant long-term consequences for the oral cavity’s hard and soft tissues. Alveolar process fractures are particularly complicated. This case report describes the management and 12-month follow-up of a segmental maxillary alveolar process fracture involving laterally luxated primary incisors. A case of a 4-year-old boy was reported to the hospital 1 hour after an accidental fall at school, which resulted in a fracture of the maxillary alveolar process. Emergency treatment consisted of fracture reduction and repositioning of the primary incisors, followed by a semirigid splint between maxillary canines. The splints were removed at the end of week 4, and the affected primary incisors remained asymptomatic.

Hexaxial external fixator versus intramedullary nail in treating segmental tibial fractures: a retrospective study

BackgroundIt’s difficult to treat segmental tibial fractures (STFs), which are intricate injuries associated with significant soft tissue damage. The aim of this study was to compare the clinical effect of hexaxial external fixator (HEF) and intramedullary nail (IMN) in treatment of STFs.MethodsA total of 42 patients with STFs were finally recruited between January 2018 and June 2022. There were 25 males and 17 females with age range of 20 to 60 years. All fractures were classified as type 42C2 using the Arbeitsgemeinschaftfür Osteosythese/Orthopaedic Trauma Association (AO/OTA) classification. 22 patients were treated with HEF and 20 patients were treated with IMN. The condition of vascular and neural injuries, time of full weight bearing, bone union time and infection rate were documented and analyzed between the two groups. The mechanical medial proximal tibial angle (mMPTA), mechanical posterior proximal tibial angle (mPPTA), mechanical lateral distal tibial angle (mLDTA), mechanical anterior distal tibial angle (mADTA), hospital for special surgery (HSS) knee joint score, American Orthopaedic Foot and Ankle Society (AOFAS) ankle joint score, range of motion (ROM) of flexion of keen joint and ROM of plantar flexion and dorsal flexion of ankle joint were compared between the two groups at the last clinical visit.ResultsThere were no vascular and neural injuries or other severe complications in both groups. All 22 patients in HEF group underwent closed reduction but 3 patients in IMN group were treated by open reduction. The time of full weight bearing was (11.3 ± 3.2) days in HEF group and (67.8 ± 5.8) days in IMN group(P < 0.05), with bone union time for (6.9 ± 0.8) months and (7.7 ± 1.4) months, respectively(P < 0.05). There was no deep infection in both groups. In the HEF group and IMN group, mMPTA was (86.9 ± 1.5)° and (89.7 ± 1.8)°(P < 0.05), mPPTA was (80.8 ± 1.9)° and (78.6 ± 2.0)°(P < 0.05), mLDTA was (88.5 ± 1.7)° and (90.3 ± 1.7)°(P < 0.05), while mADTA was (80.8 ± 1.5)° and (78.4 ± 1.3)°(P < 0.05). No significant differences were found between the two groups at the last clinical visit concerning HSS knee joint score and AOFAS ankle joint score, ROM of flexion of keen joint and ROM of plantar flexion of ankle joint (P > 0.05). The ROM of dorsal flexion of ankle joint in IMN group was (30.4 ± 3.5)°, better than (21.6 ± 2.8)° in HEF group (P < 0.05).ConclusionIn terms of final clinical outcomes, the use of either HEF or IMN for STFs can achieve good therapeutic effects. While HEF is superior to IMN in terms of completely closed reduction, early full weight bearing, early bone union and alignment. Nevertheless, HEF has a greater impact on the ROM of dorsal flexion of the ankle joint, and much more care and adjustment are needed for the patients than IMN.

Biomechanical analysis and comparison between ‘Zeta’ miniplate design and conventional miniplate system for fixation of fracture segments in transition zone of parasymphysis body region of mandible – an in vitro study

The parasymphysis area of the mandible is highly dynamic because it is subjected to both occlusal and muscular forces. As a result, the fractures in this transition zone have a special pattern, posing a challenge for surgeons whether to use one miniplate versus two miniplates, as per Champy's recommendations. The commonest complication resulting to treat this area is mental nerve paraesthesia due to the dissection and stretching of the nerve. Hence, an in vitro research study of a newly designed ‘Zeta’ miniplate is performed, to evaluate the biomechanical behaviour using finite element (FE) analysis and biomechanical analysis along with a comparison study with the conventional miniplate configurations. The results showed that the Zeta miniplate produces the lowest stresses 17.511 MPa and the least total structural deformation of 0.0011 mm after applying the maximum occlusal bite force. On application of torsional load, total structural deformation was 0.0004 mm and von Mises (VM) stress value was 0.24 MPa which was lowest when compared with the two miniplate system. Hence, the newly developed Zeta miniplate is superior in terms of stability. Another benefit of its design is that it helps in preventing mental nerve paraesthesia and tooth root damage while fixing and stabilising the fractured bony segments.

A Novel Method in Restoring Form and Function Following Malunited Isolated Zygomatic Arch Fractures- A Technical Note

Isolated zygomatic arch fractures of the facial skeleton are rare. Blunt force to the cheek can result in an isolated zygomatic arch fracture, with resulting aesthetic issues such as indendations and functional impairments such as trismus. Symptomatic or visible isolated zygomatic arch fractures are commonly treated using either the Keen (intraoral) or Gillies (temporal) approaches to reduce the fracture while avoiding visible scars. Typically, the reduced fractures are not rigidly fixated but rather held in place by the native periosteal sleeve. However, cold fractures of the zygomatic arch are difficult to treat as they require a wide area of exposure for re-osteotomy and fixation. In the present technical note, we describe a novel technique to overcome this. Through a minimally invasive approach, two osteotomies were made proximally and distally to the fracture segment, and the segment was rolled 180 degrees along the sagittal axis. The medially depressed zygomatic arch is now projected laterally and was found to give adequate prominence and relieve restrictions in mouth opening. This is a novel method for reestablishing the prominence of the zygomatic arch and aiding in mandibular function following malunion of the fractured, isolated zygomatic arch.

Bio-mechanical effects of femoral neck system versus cannulated screws on treating young patients with Pauwels type III femoral neck fractures: a finite element analysis

IntroductionAs a novel internal fixation for femoral neck fractures, the femoral neck system has some advantages for young Pauwels type III femoral neck fractures without clear biomechanical effects and mechanisms. Thus, the objection of the study is to realize the biomechanical effects and mechanism of FNS cannulated screws on treating young patients with Pauwels type III femoral neck fractures compared to cannulated screws which are commonly used for femoral neck fractures by finite element analysis.MethodsFirstly, the model of young Pauwels type III femoral neck fractures, femoral neck system (FNS), and three cannulated screws (CS) arranged in an inverted triangle were established, and the internal fixations were set up to fix young Pauwels type III femoral neck fractures. Under 2100 N load, the finite element was performed, and the deformation, peak von Mises stress (VMS), and contact at fracture segments were recorded to analyze the biomechanical effects and mechanism of FNS and three-CS fixing young Pauwels type III femoral neck fractures.ResultsCompared to three-CS, the deformation of the whole model, internal fixation, and fracture segments after FNS fixation were lower, and the peak VMS of the whole model and the internal fixation after FNS were higher with lower peak VMS of the distal femur and the fracture segments. With a sticking contact status, the contact pressure at fracture segments after FNS fixation was lower than that of three-CS.ConclusionsFNS can provide better mechanical effects for young patients with Pauwels type III femoral neck fractures, which may be the mechanical mechanism of the clinical effects of FNS on femoral neck fracture. Although there is high stress on FNS, it is still an effective and safe internal fixation for young patients with Pauwels type III femoral neck fractures.

Clinical efficacy and influencing factors of percutaneous kyphoplasty for osteoporotic vertebral compression fractures: a 10-year follow-up study

BackgroundTo date, few reports have evaluated the long-term outcome of percutaneous kyphoplasty (PKP) for osteoporotic vertebral compression fractures (OVCFs) and the factors influencing the long-term outcome of this procedure are uncertain.MethodsA total of 91 patients underwent PKP for thoracolumbar OVCFs from June 2012 to December 2012. Pain Visual Analogue Scores (VAS) and Oswestry Disability Index (ODI) were recorded preoperatively and after 10-year follow-up. Factors that may affect surgical outcome, such as gender, age, height, weight, hypertension, diabetes, cause of injury, fracture segment, length of hospitalization, history of previous spinal surgery, preoperative bone mineral density (BMD), preoperative VAS and ODI scores, length of surgery, bone cement dosage, postoperative standardized anti-osteoporosis treatment, and other new vertebral fractures, were analyzed by multiple linear regression with VAS and ODI scores at the last follow-up. The correlation factors affecting the efficacy were analyzed.ResultsThe preoperative and final follow-up pain VAS was 7.9 ± 1.1 and 2.2 ± 1.1. ODI scores were 30.4 ± 4.2 and 10.7 ± 2.6. The difference was statistically significant (P < 0.05). Most of the patients were females aged 65–75 years who suffered low-energy injuries, with most of the fracture segments in the thoracolumbar region (T11-L2). At the final follow-up visit, 12 cases (13.19%) developed other new vertebral fractures, and 33 cases (36.26%) continued to adhere to anti-osteoporosis treatment after discharge. Multiple linear regression analysis showed that there was a statistical difference between gender and VAS score at the last follow-up (P < 0.05), and between age, cause of injury and postoperative standardized anti-osteoporosis treatment and ODI at the last follow-up (P < 0.05). There were no statistically significant differences between the other factors and the final follow-up VAS and ODI scores (P > 0.05).ConclusionThe long-term outcome after PKP is satisfactory. Age, gender, cause of injury, and standardized postoperative anti-osteoporosis treatment may be factors affecting the long-term outcome.

EXPERIENCE OF THE SEGMENTAL BONE DEFECTS' TREATMENT FOR PATIENTS WITH COMBAT TRAUMA USING THE METHOD OF DISTRACTION OSTEOGENESIS

Upper and lower limb injuries resulting from battlefield trauma is a complex multidisciplinary problem. Efficacy of the treatment of segmental bone defects in patients with combat trauma is a subject of analysis for improving its results. Purpose. An analysis of the modern treatment strategies of the segmental bone defects in patients with battlefield trauma under conditions of distraction osteogenesis (based on data available in the literature and own clinical experience). Methods. Analytical review of scientific works and analysis of treatment results of 39 patients with segmental bone defects associated with battlefield trauma and treated using distraction osteogenesis were conducted. Results. Patients with segmental limbs defects require special attention of a multidisciplinary team of specialists to identify reconstructive opportunities to save the limb. Distraction osteogenesis — is an effective method of treating of segmental fractures and shortening of the limbs, infectious complications that led to bone defect formation. Bone transport with ring external fixator (ExFix) is considered as a classical method. Authors analyzed and illustrated with three clinical cases their own results of application of different distraction osteogenesis technique. Conclusions. Different types of ExFix can be applied independently or in combination with internal fixators. The use of an intramedullar nail along which distraction osteogenesis is carried out allows to provide better control of the axis of the limb and transported fragment, reduce the residence time in the ExFix, and, moreover, external fixation devices with a simpler configuration can be used. Transport along the plate allows to maintain proper axial relationships in the presence of short periarticular fragments and improve the quality of fixation but it also increases the risks of FRI and re-operations.

Deep learning for acute rib fracture detection in CT data: a systematic review and meta-analysis.

To review studies on deep learning (DL) models for classification, detection, and segmentation of rib fractures in CT data, to determine their risk of bias (ROB), and to analyse the performance of acute rib fracture detection models. Research articles written in English were retrieved from PubMed, Embase, and Web of Science in April 2023. A study was only included if a DL model was used to classify, detect, or segment rib fractures, and only if the model was trained with CT data from humans. For the ROB assessment, the Quality Assessment of Diagnostic Accuracy Studies tool was used. The performance of acute rib fracture detection models was meta-analysed with forest plots. A total of 27 studies were selected. About 75% of the studies have ROB by not reporting the patient selection criteria, including control patients or using 5-mm slice thickness CT scans. The sensitivity, precision, and F1-score of the subgroup of low ROB studies were 89.60% (95%CI, 86.31%-92.90%), 84.89% (95%CI, 81.59%-88.18%), and 86.66% (95%CI, 84.62%-88.71%), respectively. The ROB subgroup differences test for the F1-score led to a p-value below 0.1. ROB in studies mostly stems from an inappropriate patient and data selection. The studies with low ROB have better F1-score in acute rib fracture detection using DL models. This systematic review will be a reference to the taxonomy of the current status of rib fracture detection with DL models, and upcoming studies will benefit from our data extraction, our ROB assessment, and our meta-analysis.

MSFF: An automated multi-scale feature fusion deep learning model for spine fracture segmentation using MRI

Spinal fractures pose a significant healthcare challenge, impacting patient care and clinical decisions. Accurately identifying these fractures from medical images is crucial due to their location, shape, type, and severity. Meeting these challenges often necessitates employing advanced machine learning and deep learning techniques. This study introduces a novel deep learning model called MSFF (Multi-Scale Feature Fusion) specifically designed for automated spine fracture segmentation using MRI images. The MSFF architecture comprises five key modules: the Feature Fusion Module (FFM), Squeeze and Excitation (SEM), Atrous Spatial Pyramid Pooling (ASPP), Residual Convolution Block Attention Module (RCBAM), Residual Border Refinement Attention Block (RBRAB), and Local Position Residual Attention Block (LPRAB). These modules collectively facilitate multi-scale feature fusion, spatial feature extraction, channel-wise feature enhancement, segmentation border refinement, and focused attention on the region of interest. Subsequently, a decoder network is employed to predict fractured spine areas. Experimental findings demonstrate that the proposed MSFF approach attains superior accuracy in addressing the challenges and outperforms existing segmentation methods.

Assessment of Cement Leakage in Decompressed Percutaneous Kyphoplasty.

Symptomatic osteoporotic compression fractures are commonly addressed through vertebroplasty and kyphoplasty. However, cement leakage poses a significant risk of neurological damage. We introduced "aspiration percutaneous kyphoplasty", also known as "decompressed kyphoplasty", as a method to mitigate cement leakage and conducted a comparative analysis with high viscosity cement vertebroplasty. We conducted a retrospective study that included 136 patients with single-level osteoporotic compression fractures. Among them, 70 patients underwent high viscosity cement vertebroplasty, while 66 patients received decompressed percutaneous kyphoplasty with low-viscosity cement. Comparison parameters included cement leakage rates, kyphotic angle alterations, and the occurrence of adjacent segment fractures. The overall cement leakage rate favored the decompressed kyphoplasty group (9.1% vs. 18.6%), although statistical significance was not achieved (p = 0.111). Nonetheless, the risk of intradiscal leakage significantly reduced in the decompressed kyphoplasty cohort (p = 0.011), which was particularly evident in cases lacking the preoperative cleft sign on X-rays. Kyphotic angle changes and the risk of adjacent segment collapse exhibited similar outcomes (p = 0.739 and 0.522, respectively). We concluded that decompressed kyphoplasty demonstrates efficacy in reducing intradiscal cement leakage, particularly benefiting patients without the preoperative cleft sign on X-rays by preventing intradiscal leakage.

Better Rough than Scarce: Proximal Femur Fracture Segmentation with Rough Annotations.

Proximal femoral fracture segmentation in computed tomography (CT) is essential in the preoperative planning of orthopedic surgeons. Recently, numerous deep learning-based approaches have been proposed for segmenting various structures within CT scans. Nevertheless, distinguishing various attributes between fracture fragments and soft tissue regions in CT scans frequently poses challenges, which have received comparatively limited research attention. Besides, the cornerstone of contemporary deep learning methodologies is the availability of annotated data, while detailed CT annotations remain scarce. To address the challenge, we propose a novel weakly-supervised framework, namely Rough Turbo Net (RT-Net), for the segmentation of proximal femoral fractures. We emphasize the utilization of human resources to produce rough annotations on a substantial scale, as opposed to relying on limited fine-grained annotations that demand a substantial time to create. In RT-Net, rough annotations pose fractured-region constraints, which have demonstrated significant efficacy in enhancing the accuracy of the network. Conversely, the fine annotations can provide more details for recognizing edges and soft tissues. Besides, we design a spatial adaptive attention module (SAAM) that adapts to the spatial distribution of the fracture regions and align feature in each decoder. Moreover, we propose a fine-edge loss which is applied through an edge discrimination network to penalize the absence or imprecision edge features. Extensive quantitative and qualitative experiments demonstrate the superiority of RT-Net to state-of-the-art approaches. Furthermore, additional experiments show that RT-Net has the capability to produce pseudo labels for raw CT images that can further improve fracture segmentation performance and has the potential to improve segmentation performance on public datasets. The code is available at: https://github.com/zyairelu/RT-Net.

Variation in the Branching Pattern of the Radial Nerve Observed during Fixation of the Humerus Shaft: A Case Report

The posterior cord of the brachial plexus typically maintains a consistent branching pattern, and deviations from this norm are exceedingly rare. Even more infrequently encountered are variations in the branching pattern of the radial nerve. The current case report of a 45-year-old male patient presents a unique clinical scenario involving a middle third and distal third humerus shaft fracture, manifesting as the chief complaint of pain during movement, coupled with localised swelling. A posterior approach was employed for surgical intervention due to the expansile nature of the fracture within the middle and distal thirds. During the surgical exploration, an anomalous branching pattern of the radial nerve was observed when transitioning from the posterior to the anterior compartment. This atypical radial nerve branching consisted of a branch extending into the anterior compartment and an accompanying posteroinferior branch, which notably supplied the medial and long heads of the triceps muscle. The present case underscores the imperative role of the orthopaedic surgeon in considering the radial nerve's intricate anatomy while exposing and stabilising segmental humerus fractures. It is of paramount importance to exercise vigilance, as the conventional practice of splitting the triceps muscle should be abstained from until an unusual branching or splitting of the radial nerve is definitively ruled out. The present case report elucidates the significance of meticulous anatomical awareness and surgical technique when addressing such complex humeral fractures, offering insights into the management of these uncommon clinical presentations.

Impact of Angle of File Access and Location of Canal Curvature on the Dynamic Cyclic Fatigue of Nickel Titanium Rotary Instruments.

To evaluate the impact of different file access angles and root canal curvature's location on the fatigue failure of One Curve (OC) and E3 Azure (EZ) NiTi files using a dynamic model at simulated body temperature. Eighty new instruments with similar tip sizes and taper (#25/0.06) from two NiTi rotary systems, One Curve and E3 Azure, were tested at simulated body temperatures (37°C) using a custom-made dynamic cyclic fatigue device. Instruments were divided into four subgroups according to the location of root canal curvature (a coronal curve 5 mm from the root canal orifice and an apical curve 10 mm from the root canal orifice) and the angle of file access (0° or 30°). Instruments were operated in simulated stainless-steel canals having a 60° curve and a 3 mm radius. A custom-made device produced controlled vertical pecks during file rotation. Time to failure (sec) was registered, and the length of the fragment segments was measured (mm). Data were analysed statistically with One-Way ANOVA and Tukey post hoc tests. The significance level was set at 5%. All separated instruments were examined by scanning electron microscope. One-way ANOVA (p<0.05) found a significant difference among the tested instruments. Post Hoc analysis revealed lower cyclic fatigue resistance when the angle of file access was 30º, and the root canal curvature was located coronally for both files (p<0.0001). Three-way ANOVA showed that the angle of file access was the most influential contributor to cyclic fatigue, followed by the location of file curvature and, finally, the file type (p<0.0001). The fractographic examination revealed a predominantly ductile fracture mode for all tested instruments. The lengths of all fractured segments showed no significant difference (p>0.05), indicating an accurate trajectory during testing. OC files had superior cyclic fatigue resistance than EZ files; coronal curvatures negatively impacted cyclic fatigue resistance compared to apical curvatures, while the angle of file access presented the highest impact on dynamic cyclic fatigue.

Protect Clavicle to Avoid Sports Associated Clavicle Fracture-Still Even Segmental Fracture Can Be Managed Well with Surgery in Today's Era

Clavicle is an S-shaped subcutaneous bone which increases the band ring power of the shoulder. Clavicle fractures account for approximately 4% of all fractures. Fractures occur most commonly in the middle third of the bone (76-82%) and less often in the distal (12-21%) and medial (3-6%) thirds.

Evaluation of the Cyclic Fatigue Resistance of Tia Tornado Blue and Tia Tornado Gold in Curved Canals: In Vitro Study

(1) Background: The aim of this study was to investigate the cyclic fatigue behavior of the newly introduced endodontic instrument systems Tia Tornado Blue and Tia Tornado Gold. (2) Methods: The tested rotary instruments were divided according to their type into four groups as follows: Tia Tornado Blue (TTB), Tia Tornado Gold (TTG), Protaper Gold (PTG), and Vortex Blue (VB). The cyclic fatigue resistance of fifteen instruments of each group, totaling 60, was tested. Each instrument was rotated under continuous motion inside an artificial canal at simulated body temperature at the speed recommended by the manufacturer until fracture. The time to fracture was recorded, and the number of cycles to fracture (NCF) was calculated for each instrument. Additionally, the fractured segment length was calculated, and scanning electron microscopic (SEM) images were captured of the fractured surfaces. (3) Results: Statistical analysis revealed that the VB significantly had the highest NCF followed by the PTG, TTG, and TTB (p &lt; 0.05). The lengths of the fractured segments were found to be similar among the tested instrument, which ranged from 4.42 to 4.86 mm (p &gt; 0.05). SEM images exhibited the typical features of cyclic fatigue. (4) Conclusions: The newly introduced instruments, TTG and TTB, exhibited a significantly lower resistance to cyclic fatigue compared to the PTG and VB rotary instruments.

Consistent treatment of shear failure in embedded discrete fracture models using XFVM

AbstractUnderstanding deformations and fluid flow in fractured rocks is of central importance for many subsurface flow applications. Thus, numerical frameworks are needed that capture the coupled mechanical and hydraulic behaviour, including scenarios with complex fracture networks. This paper employs the extended finite volume method to represent fracture manifolds in a poroelastic matrix domain and to compute shear and tensile displacements of fracture segments. However, using embedded fractures with non‐conforming grids can lead to severe convergence issues while computing shear slip and tensile opening of intersecting and parallel fractures, particularly if they have similar slopes. Our proposed solution of this problem is to slightly deform the fracture geometry by merging critical segments. We discuss and show examples of which attributes the merged segment has to adopt to ensure the correct slip behaviour at an intersection. Thereby it is crucial that the flow topology remains unaltered. Analysing failures of kinked fractures and fracture intersections show the flexibility of the devised algorithm. Moreover, it is demonstrated that deformation and opening patterns of a natural network with more than 200 fractures are qualitatively predicted very well. This method is a simple solution to treat multiple fracture segments in a grid cell, hence it can be used for any model embedding fractures in non‐conforming grids.

A deep-learning approach for dynamic region merging applied to feature extraction from borehole microresistivity images

The primary purpose of processing borehole resistivity images is to identify and extract high (or low) resistivity anomalous areas, which are associated with resistive fractures and dissolved pores. To improve the accuracy and applicability of these models, a new intelligent method combining dynamic-region merging (DRM) with a deep-learning network (U-net) is proposed. The superpixel method, also referred to as linear spectral clustering (LSC), was applied to segment fractures and dissolved pores that are represented by a resistivity contrast in the original resistivity images. The sequential probability ratio test technique was then used to implement the DRM procedure to group many oversegmented small regions. A convolutional neural network (U-net architecture) model was used to automatically identify geologic features with various scales. The trained neural network was then used to identify the segmented resistivity images that had been processed by the DRM. The results showed that the superpixel algorithm and U-net combination significantly improved the accuracy of the classification and identification of fractures and dissolved pores in different test data sets. Moreover, it solved the problem of few-shot learning, enabling a pretrained model to generalize over new data categories.

Inside–Outside: Extracorporeal Fixation of Condyle: A Case Report

Fracture of the condylar process is the most common site within the fractures of the mandible and causes problems such as occlusal dysfunction, temporomandibular joint dysfunction, and facial deformities. Therefore, proper treatment of this entity is paramount in preventing such problems. Essentially, there are three treatment approaches, namely, observational, close reduction and open reduction, and internal fixation. 1 The debate between open and close reduction has been going on ever since with the proof that open reduction aims at restoring the facial asymmetry of the patient faster: although it has its own demerits like limited access even through surgical exposure and difficulty in reduction. Medially displaced fractures that pose such problems are treated with extracorporeal fixation of the fractured segment. 2 We hereby present such a case with the detailed technique and the literature around it.