Traditional Fusion Techniques Research Articles

Effectiveness of Interspinous Process Devices in Managing Adjacent Segment Degeneration Following Lumbar Spinal Fusion: A Systematic Review and Meta-Analysis.

Background: Adjacent segment degeneration (ASD) is a significant complication following lumbar spinal fusion, often necessitating further surgical interventions and impairing patient outcomes. Interspinous process devices were introduced as an alternative treatment for spinal stenosis and degenerative spondylolisthesis and can potentially reduce the incidence of ASDd. This systematic review and meta-analysis aims to evaluate the effectiveness of interspinous process devices or IPDs in managing ASD following a previous spinal fusion compared to traditional fusion techniques. Methods: Electronic databases, including PubMed, Embase, and the Cochrane Library, were queried for studies assessing IPDs against traditional lumbar fusion methods for managing ASD after previous lumbar fusion, which had been published between January 2014 and the present. Statistical analysis was conducted using Review Manager 5.4. Results: Seven retrospective cohort studies involving 546 patients met the inclusion criteria. The analysis revealed that IPDs were associated with a statistically significant reduction in the incidence of ASD (OR = 0.28, 95% CI: 0.16 to 0.51, p < 0.0001, and I2 = 0% after excluding outliers). The ODI demonstrated a non-significant trend towards improved outcomes with IPDs at the 2-year follow-up (SMD = -3.94; 95% CI: -11.72 to 3.85). Range of motion (ROM) was better preserved with IPDs compared to fusion (SMD = 0.00, 95% CI: -0.41 to 0.41, p = 1.00, I2 = 60%). The visual analogue scale or VAS lower back pain scores were significantly reduced at the 2-year follow-up (SMD = -0.69, 95% CI: -1.18 to -0.19, p = 0.006, and I2 = 74%). VAS leg pain showed consistent improvements (SMD = -0.29; 95% CI: -0.63 to 0.04). Intraoperative blood loss was significantly lower with IPDs (SMD = -2.07; 95% CI: -3.27 to -0.87, p = 0.0007, and I2 = 95%), and operation times were shorter (SMD = -2.22, 95% CI: -3.31 to -1.12, p < 0.0001, and I2 = 94%). Conclusions: The judicious use of IPDs might benefit a subset of patients, particularly those who are not suitable candidates for major corrective surgery.

Multimodal fusion hierarchical self-attention network for dynamic hand gesture recognition

Recent improvements in dynamic hand gesture recognition have seen a shift from traditional convolutional architectures to attention-based networks. These attention networks have been proven to outclass CNN + LSTM architectures, showing higher accuracy as well as reduced model parameters. Especially, skeleton-based attention networks have been shown to outperform visual-based networks due to the rich information from skeleton-based hand features. However, there is an opportunity to introduce complementary features from other modalities like RGB, depth, and optical flow images to enhance the recognition capability of skeleton-based networks. This paper aims to explore the addition of a multimodal fusion network to a skeleton-based Hierarchical Self-Attention Network (MF-HAN) and test for increased model effectiveness. Unlike traditional fusion techniques, this fusion network uses features derived from other sources of multimodal data in a reduced feature space using a cross-attention layer. The model outperforms its root model and other state-of-the-art models on the SHREC’17 track dataset, especially in the 28 gestures setting by more than 1 % in gesture classification accuracy. The experimentation was tested on the DHG dataset as well.

Applying deep-learning enhanced fusion methods for improved NDVI reconstruction and long-term vegetation cover study: A case of the Danjiang River Basin

The Normalized Difference Vegetation Index (NDVI) is an essential metric in vegetation monitoring for remote sensing applications. While there are numerous long-term low-resolution NDVI datasets available there remains an unmet need for high-resolution NDVI reconstructions over extended time frames. Existing research has not comprehensively assessed the efficacy of various temporal fusion techniques for NDVI reconstruction at large regional scales. Traditional Spatiotemporal Image Fusion (TSTIF) methods often suffer from limited fusion accuracy due to input data quality constraints. To address these limitations this study introduces an innovative Deep Learning-Enhanced Spatiotemporal Fusion Method. Deep learning algorithms are employed to refine the spatial resolution of input data thereby facilitating the separation of complex image elements located at feature boundaries. This improved approach significantly enhances fusion accuracy as validated against five established TSTIF techniques through empirical analysis. As a case study we generate long-term Fractional Vegetation Cover (FVC) datasets to investigate the ecological dynamics of the Danjiang River Basin. Our findings reveal substantial gains in NDVI reconstruction accuracy through the incorporation of deep learning into traditional fusion techniques. Among the methods tested the STRUM algorithm showed the greatest improvement with its R2 value increasing from 0.872 to 0.894 and a consistent reduction in Root Mean Square Error (RMSE). The FSDAF technique emerged as the most effective boasting an R2 value of 0.953 and an RMSE of 0.012. These enhanced NDVI datasets provide more accurate representations of the basin's vegetation cover thus enriching long-term observational archives and facilitating further quantitative remote sensing analyses. Moreover we report a 21-year mean FVC of 0.702 for the Danjiang River Basin characterized by a “north-high south-low” distribution that varies seasonally. Improvements in vegetation cover were observed in Xichuan and Neixiang counties while environmental degradation is evident in the broader Danjiang River watershed. Key factors influencing these spatial variations include elevation and soil composition in addition to climate variables such as rainfall and temperature. Infrastructure projects like the South-to-North Water Diversion Project and targeted ecological conservation policies have also positively impacted vegetation within the basin.

Clinical efficacy of midline lumbar interbody fusion arthrodesis with neuronavigation-guided cortical bone trajectory screws in the treatment of degenerative lumbar spondylolisthesis:a prospective randomized controlled trial

Introduction. Currently, the standard treatment of degenerative spondylolisthesis involves pedicle screw fixation to enhance the success of intervertebral fusion. The traditional pedicle screw techniques require extensive lateral muscle dissection, resulting in significantly increased surgical-related morbidity. To address some of these shortcomings, the Midline Lumbar Interbody Fusion (MIDLIF®) technique has recently been developed. It involves the combination of the cortical bone trajectory screw fixation of the spine with intervertebral cage placement to achieve a solid interbody fusion. So far, the clinical efficacy of the MIDLIF technique in the treatment of low-grade degenerative spondylolisthesis is still unknown. All existing publications are studies with a low level of relevance or scientific evidence. Materials and methods. A prospective randomized controlled trial was conducted between 2017 and 2022. The study analyzed the clinical and radiological effectiveness of the MIDLIF arthrodesis technique compared to the traditional lumbar interbody fusion techniques, used exclusively in the treatment of degenerative lumbar spondylolisthesis. Results. The study enrolled 112 eligible patients with degenerative low-grade spondylolisthesis, randomly assigned into two groups. At 1 year post-operatively, MIDLIF provided a significantly better improvement in postoperative relief of low back pain and radiating pain, as well as a significantly better functional recovery. Additionally, MIDLIF resulted in lower surgical morbidity compared to traditional fusion techniques. Conclusions. The success rate of MIDLIF arthrodesis is similar to that associated with traditional fusion techniques. At the same time, MIDLIF offers all the specific benefits of a minimally invasive approach, such as less postoperative pain, faster functional recovery, less bleeding, and fewer blood transfusions. Thus, MIDLIF might be a good alternative to the traditional intervertebral fusion techniques in the treatment of degenerative low-grade spondylolisthesis.

Chemical and Enzymatic Methods for Post-Translational Protein-Protein Conjugation.

Fusion proteins play an essential role in the biosciences but suffer from several key limitations, including the requirement for N-to-C terminal ligation, incompatibility of constituent domains, incorrect folding, and loss of biological activity. This perspective focuses on chemical and enzymatic approaches for the post-translational generation of well-defined protein–protein conjugates, which overcome some of the limitations faced by traditional fusion techniques. Methods discussed range from chemical modification of nucleophilic canonical amino acid residues to incorporation of unnatural amino acid residues and a range of enzymatic methods, including sortase-mediated ligation. Through summarizing the progress in this rapidly growing field, the key successes and challenges associated with using chemical and enzymatic approaches are highlighted and areas requiring further development are discussed.

Finite analysis of stability between modified articular fusion technique, posterior lumbar interbody fusion and posteriorlateral lumbar fusion

BackgroundIt is not clear whether modified facet fusion (MFF) is biomechanically different from traditional fusion techniques such as posterior lateral lumbar fusion (PLF) and posterior lumbar interbody fusion (PLIF).MethodsIn this study, a healthy adult Chinese male volunteer was selected to perform 3D reconstruction of CT image data and simulate the successful fusion of L4–5 MFF, PLF and PLIF, respectively. The motion range of L4–5 segments of the model was simulated under 6 working conditions, including forward flexion, extension, lateral flexion and rotation under normal physiological conditions, and the stability of the three fusion procedures in the pathological segments of the lumbar spine was compared.ResultsThere was no difference in range of motion between MFF model and PLF or PLIF model (P < 0.05). Also, the stiffness of the PLFand the MFF model were comparable (P > 0.05), but were smaller than the PLIF model (P < 0.05).ConclusionsMFF provides reliable stability at the lumbar fixation fusion level and does not differ significantly from PLF and PLIF in terms of range of motion.

A very high-resolution scene classification model using transfer deep CNNs based on saliency features

Developing remote sensing technology enables the production of very high-resolution (VHR) images. Classification of the VHR imagery scene has become a challenging problem. In this paper, we propose a model for VHR scene classification. First, convolutional neural networks (CNNs) with pre-trained weights are used as a deep feature extractor to extract the global and local CNNs features from the original VHR images. Second, the spectral residual-based saliency detection algorithm is used to extract the saliency map. Then, saliency features from the saliency map are extracted using CNNs in order to extract robust features for the VHR imagery, especially for the image with salience object. Third, we use the feature fusion technique rather than the raw deep features to represent the final shape of the VHR image scenes. In feature fusion, discriminant correlation analysis (DCA) is used to fuse both the global and local CNNs features and saliency features. DCA is a more suitable and cost-effective fusion method than the traditional fusion techniques. Finally, we propose an enhanced multilayer perceptron to classify the image. Experiments are performed on four widely used datasets: UC-Merced, WHU-RS, Aerial Image, and NWPU-RESISC45. Results confirm that the proposed model performs better than state-of-the-art scene classification models.

Preclinical evaluation of a novel anterior non-fusion fixation device for atlantoaxial instability: an in vivo comparison study in a canine model.

The Anterior Atlantoaxial Non-Fusion Fixation System (AANFS) was a novel motion preservation device for atlantoaxial instability to replace traditional fusion techniques. The purpose of this in vivo study was to evaluate the clinical features and biomechanical properties of this new device in a canine model by comparing it with a conventional method. Eighteen adult male canines were randomly divided into group 1, which received the AANFS replacement, group 2 which received the Harms rigid fixation procedures, and group 3, which served as the control group. Routine follow-up evaluations were performed postoperatively. Specimens were harvested 12weeks after the operation. Biomechanical tests were conducted to obtain the range of motion (ROM) and neutral zone (NZ) at C1-C2 segment in different groups. The canines successfully tolerated the entire experimental procedure. No significant differences were found in surgery time, blood loss and recovery time between the AANFS group and the Harms rigid fixation group. Radiological examinations revealed that the position of the implant was good. Biomechanical results showed that, compared with the intact group, the mean ROM and NZ in flexion, extension, lateral bending and rotation were significantly reduced after rigid fixation. However, after the AANFS implantation, ROM and NZ in all directions were similar to those of the intact state. This study for the first time provides an animal model for studying non-fusion strategies of upper cervical spine. The AANFS was able to maintain movement function of the atlantoaxial joint and may be an alternative to traditional fusion techniques. These slides can be retrieved under Electronic Supplementary Material.

Fusion of Remote Sensing Images

Abstract Recently, there has been greater interest in the Hyper spectral (HS) sensing technology as the information that resides in the HS spectral domain provides significant advantages over the traditional Multi spectral images. The inherent tradeoff between the spectral and spatial resolutions has resulted in the development of remote sensing systems that include fusion of Hyper spectral image and Multi spectral image taken over the same image scene. In this proposed work Matrix Factorization (MF) Un mixing based fusion method is used for the fusion of the HS image and the MS image to produce a fused image data that will be enhanced in terms of its both spatial and spectral qualities which in turn contributes for the accurate identification and classification of various materials in the observed image scene. This algorithm is very straight forward and easy to implement owing to its simple update rules. The effectiveness of the proposed fusion technique for fusion of HS image and MS image over the other traditional fusion techniques like wavelet based fusion and IHS fusion, is analyzed in terms of the spatial and spectral performance metrics.

Image fusion using nonlinear discrete multiresolution transform: the case of harmonic mean

During the last two decades, the need for better image quality and functionality has led to seek for new algorithms of enhancement which overcome the technology restrictions. Among such algorithms, image fusion is employed in a wide variety of fields, such as aerial photos, astronomy, remote sensing, optical microscopy or medical imaging. Multiresolution decompositions have proved their superiority against other traditional fusion techniques since they lead to a better separation of geometrical details. The aim of this paper is to contribute to the existing image fusion methods with the introduction of a nonlinear variant of the classical ‘à trous’ algorithm, which is an important and well-known tool for image fusion. The proposed algorithm is also shift invariant. This property together with the use of some nonlinear components, well behaved in the presence of discontinuous data, make possible to improve some features of the resulting image in comparison with standard linear techniques. This improvement is tested by numerical experiments.

Fatigue Behaviour of Friction Stir Welded Rolled Thick Plates of AA7075-T651 Aluminium Alloy Joints

The fatigue strength of welded joints represents the core problem for their industrial applications. Friction stir welding (FSW) demonstrated the enhancement of fatigue resistance for aluminium alloys, with respect to traditional fusion techniques. The aim of the present work is to evaluate the fatigue properties of 12 mm thick AA 7075 -T651 aluminium alloy plates joined by friction stir welding (FSW) process. The fatigue properties were evaluated under uniaxial tensile loading condition (stress ratio = 0.1, Frequency=10Hz) at room temperature using servo-hydraulic controlled machine. The fatigue endurance (S-N) curves of the welded joints and unwelded parent metal were constructed. The resultant fatigue properties were correlated with the tensile, hardness and microstructural characteristics of welded joints. The mode of failure was analyzed through scanning electron microscopy. It is found that the fatigue life of friction stir welded AA 7075- T651 Aluminium alloy joints is appreciably lower than unwelded parent metal but it is higher than fusion welded joints.

Nonnegative matrix factorization-based hyperspectral and panchromatic image fusion

The fusion of hyperspectral image and panchromatic image is an effective process to obtain an image with both high spatial and spectral resolutions. However, the spectral property stored in the original hyperspectral image is often distorted when using the class of traditional fusion techniques. Therefore, in this paper, we show how explicitly incorporating the notion of “spectra preservation” to improve the spectral resolution of the fused image. First, a new fusion model, spectral preservation based on nonnegative matrix factorization (SPNMF), is developed. Additionally, a multiplicative algorithm aiming at get the numerical solution of the proposed model is presented. Finally, experiments using synthetic and real data demonstrate the SPNMF is a superior fusion technique for it could improve the spatial resolutions of hyperspectral images with their spectral properties reliably preserved.

Friction Based Solid State Welding Processes

In the last decade the industrial use of solid state welding processes based on frictional forces work decaying into heat is continuously increasing due to their strong advantages with respect to traditional fusion techniques. Several advances have been proposed by the scientific community regarding process mechanics, material flow and also the computer aided engineering of the operation with the aim to maximize the mechanical performances of the welded joints. In the paper Friction Stir Welding (FSW) and Linear Friction Welding (LFW) operations are considered and a review of the most relevant research issues and results is provided.

Optimal quality for image fusion with interpolatory parametric filters

Abstract A possible definition of the term fusion could be a simultaneous combination of output information from several sources. Using complementary data, image fusion may improve quality and consequently interpretability of the result. There are many different ways to proceed with image fusion and several general frameworks have been used for fusing images. Standard image fusion methods are often successful at injecting spatial detail into the multispectral imagery but distort the color information in the process. During the last decade a great amount of research has been devoted concerning the application of wavelet transforms in image fusion. Multiresolution decompositions have proved their superiority against other traditional fusion techniques, particularly in terms of minimizing color distortion. By other side, the subject of wavelet has an interdisciplinary relation to subdivision schemes, which has brought on reciprocal interest in both areas. In this work we propose to use a class of subdivision filters or masks depending on a control parameter in order to perform image fusion in the framework of shift invariant discrete multiresolution transforms. As a consequence, we obtain a fusion procedure with a free parameter. This degree of freedom have two main advantages. First, by giving different numerical values to the parameter it is possible to change some features of the resulting image. The second advantage is that it is possible to obtain the value of the parameter in order to solve certain constraint problem formulated in terms of standard measures. The parametric solution of the problem ensures optimal quality of the resulting fused image. In this sense, our approach provides optimal results and it is more dynamic than previous works.

A curvelet transform approach for the fusion of MR and CT images

There are several medical imaging techniques such as the magnetic resonance (MR) and the computed tomography (CT) techniques. Both techniques give sophisticated characteristics of the region to be imaged. This paper proposes a curvelet based approach for fusing MR and CT images to obtain images with as much detail as possible, for the sake of medical diagnosis. This approach is based on the application of the additive wavelet transform (AWT) on both images and the segmentation of their detail planes into small overlapping tiles. The ridgelet transform is then applied on each of these tiles, and the fusion process is performed on the ridgelet transforms of the tiles. Simulation results show the superiority of the proposed curvelet fusion approach to the traditional fusion techniques like the multiresolution discrete wavelet transform (DWT) technique and the principal component analysis (PCA) technique. The fusion of MR and CT images in the presence of noise is also studied and the results reveal that unlike the DWT fusion technique, the proposed curvelet fusion approach doesn't require denoising.

Effect of welding processes on tensile properties of AA6061 aluminium alloy joints

The present investigation is aimed at to study the effect of welding processes such as GTAW, GMAW and FSW on mechanical properties of AA6061 aluminium alloy. The preferred welding processes of these alloys are frequently gas tungsten arc welding (GTAW) and gas metal arc welding (GMAW) due to their comparatively easier applicability and better economy. In this alloy, the weld fusion zones typically exhibit coarse columnar grains because of the prevailing thermal conditions during weld metal solidification. This often causes inferior weld mechanical properties and poor resistance to hot cracking. Friction stir welding (FSW) is a solid phase welding technique developed primarily for welding metals and alloys that heretofore had been difficult to weld using more traditional fusion techniques. Rolled plates of 6 mm thickness have been used as the base material for preparing single pass butt welded joints. The filler metal used for joining the plates is AA4043 (Al-5Si (wt%)) grade aluminium alloy. In the present work, tensile properties, micro hardness, microstructure and fracture surface morphology of the GMAW, GTAW and FSW joints have been evaluated, and the results are compared. From this investigation, it is found that FSW joints of AA6061 aluminium alloy showed superior mechanical properties compared with GTAW and GMAW joints, and this is mainly due to the formation of very fine, equiaxed microstructure in the weld zone.

The mechanical properties of the GMAW, GTAW and FSW joints of the RDE-40 aluminium alloy

The present study is concerned with the effect of welding processes on the mechanical properties of the RDE-40 aluminium alloy, closely confirming with the AA7039 (Al-Zn-Mg) alloy. The frequently preferred welding processes for this alloy are Gas Tungsten Arc Welding (GTAW) and Gas Metal Arc Welding (GMAW) due to their comparatively easier applicability and better economy. In this alloy, the weld fusion zones typically exhibit coarse columnar grains because of the prevailing thermal conditions during weld metal solidification. This often results in inferior weld mechanical properties and poor resistance to hot cracking. Friction Stir Welding (FSW) is an innovative solid-phase welding technique that was developed primarily for welding metals and alloys that heretofore have been difficult to weld using more traditional fusion techniques. In the present work, the tensile properties, microhardness, microstructure and fracture surface morphology of the GMAW, GTAW and FSW joints are evaluated and results are compared. From this investigation, it is found that the FSW joints of the RDE-40 aluminium alloy shows superior mechanical properties compared with the GTAW and GMAW joints and this is mainly due to the formation of a very fine, equiaxed microstructure in the weld zone.

Effect of tool position on the fatigue properties of dissimilar 2024-7075 sheets joined by friction stir welding

The fatigue strength of welded joints represents the core problem for their industrial applications. Friction stir welding (FSW) demonstrated the enhancement of fatigue resistance for aluminium and magnesium alloys, with respect to traditional fusion techniques. In addition, the possibility to join dissimilar alloys representing an important aspect for such technology as well as the reduction of residual stresses and apparent necessity to avoid heavy heat treatments are also positive factors. In this paper, the results about the fatigue properties and the fatigue crack growth behaviour of dissimilar 2024-7075 jointed aluminium sheets are presented for FSW butt welds, produced with different positions of the tool with respect to the weld line.

Complications and Outcome of Four-Corner Arthrodesis: Circular Plate Fixation Versus Traditional Techniques

To review the clinical and radiographic results of scaphoid excision and four-corner arthrodesis using a circular plate and screws compared with traditional fusion techniques (wires, staples, screws). Fifty-eight patients with four-corner arthrodesis (plate fixation, n = 27; traditional fixation, n = 31) were evaluated for radiographic and clinical success using wrist radiographs and functional assays. Patients were subjectively surveyed using the standardized Disabilities of the Arm, Shoulder, and Hand questionnaire and classification scales for pain and satisfaction. Objective measurements included grip-strength and range-of-motion measurements. Radiographic analysis showed 26% nonunion with loose hardware in the plate group compared with 3% in the traditional group and 22% hardware impingement in the plate group compared with 3% in the traditional group. Clinical evaluation yielded a mean grip strength of 31 kg (70% of opposite side) for plate fixation and 33 kg (79% of opposite side) for traditional fixation. The mean flexion-extension arc was 48% and 50% of the opposite wrist for plate and traditional patients, respectively. The mean adjusted Disabilities of the Arm, Shoulder, and Hand questionnaire scores were 27 out of 100 for plate patients and 8 out of 100 for traditional patients. Pain classification scores showed that only 2 patients in the plate group were pain free whereas there were 8 patients in the traditional group who were pain free. Overall patient satisfaction was 60% for the plate group whereas the traditional patient group reported 100% satisfaction. The rate of major complications (nonunion or impingement) was much greater with circular plate fixation (48%) versus traditional fixation techniques (6%). With the plate procedure the grip strength and arc of motion decreased approximately 30% and 52%, respectively, compared with decreases of 21% and 50%, respectively, for traditional fusion methods. Additionally, subjective patient dissatisfaction was 40% in the plate group compared with 0% in the traditional group. We postulate that the increased complication and dissatisfaction rates associated with plate fixation may be attributable to possible biomechanical imperfections or increased technical demands with this fusion system.

The Effect of Nonsteroidal Anti-Inflammatory Agents on Spinal Fusion

A large body of information suggests NSAIDS have a negative impact on the healing of bone. Although each clinical healing scenario presents a slightly different level of challenge, the healing of a posterolateral spinal fusion is one of the most difficult challenges in bony healing. Clinically, this results in a relatively high rate of nonunions using traditional fusion techniques. Spinal fusion models have confirmed NSAIDS have a definite inhibitory effect on healing of the fusion. Although data are limited, it appears this effect is most severe when NSAIDS are administered in the early postoperative period. Moreover, the effect may be worse with certain types initial inflammatory, subsequent reparative, and final remodeling phases. Because of the anti-inflammatory activity of NSAIDS, one might assume their effects would be worse when administered in the inflammatory phase. Indeed, the study by Riew et al suggests the inhibitory effects are more significant when NSAIDS are administered earlier following fusion. Other studies conducted with non-spinal models also suggest early administration of NSAIDS results in greater inhibition of bone formation (Goodman et al). Unfortunately, the length of the inflammatory phase in humans is not well known. This leaves the clinician unsure about the safe time to allow resumption of NSAID usage clinically. It appears likely NSAID use following a spinal fusion procedure will increase the rate of pseudarthrosis. The literature suggests that avoidance of NSAIDS in the postoperative period may avoid nonunion. Additionally, we propose that chronic NSAID usage should be addressed in a similar manner to cigarette smoking. While neither are absolute contraindications to elective spinal fusion, patients should be counseled to discontinue the use of NSAIDS in the peri- and postoperative period to maximize their chance for a successful fusion.