Joint Level Research Articles

The frequency of complications in a cohort of patients diagnosed with hemophilia A and hemophilia B receiving prophylactic treatment in Colombia: A retrospective noninterventional study.

Hemophilia A and B are disorders associated with the deficit of coagulation factors VIII and IX. Was to determine the incidence of complications in a cohort of patients diagnosed with moderate and severe hemophilia A or B under treatment in a specialized institution. A retrospective study of a cohort of patients with replacement therapy for hemophilia A or B, evaluating treatment and complications between January/2012 and July/2019. Sociodemographic, clinical and disease management-related variables were extracted from the medical records. Time to inhibitor development and rate associated with bleeding and hospitalizations were evaluated. A total of 159 male patients were identified with hemophilia A (n = 140; 88.1%) and B (n = 19; 11.9%) with a mean follow-up of 5.9±2.3 years. The mean age was 23.6±16.1 years, hemophilia was reported as severe in 125 patients in hemophilia A (89.3%) and 13 patients in hemophilia B (68.4%). Primary prophylaxis was registered in 17.0% of patients, 44.7% secondary, and 38.3% tertiary, with recombinant factors (n = 84; 52.8%) followed by plasma derived factors (n = 75; 47.2%). The incidence of inhibitor development was 0.3 per 100 patients/year, with mean time to event of 509 days. The incidence of bleeding was 192 per 100 patients/year, especially at the joint (n = 99; 62.3%) and muscle (n = 25; 15.7%) level. The incidence of hospitalization was 3.7 per 100 patients/year. The most common complication was joint bleeding which was expected in this type of patients. Low proportion of patients developed factor inhibitors during the follow up.

Design and Characterization of a Self-Aligning End-Effector Robot for Single-Joint Arm Movement Rehabilitation

Traditional end-effector robots for arm rehabilitation are usually attached at the hand, primarily focusing on coordinated multi-joint training. Therapy at an individual joint level of the arm for severely impaired stroke survivors is not always possible with existing end-effector robots. The Arm Rehabilitation Robot (AREBO)—an end-effector robot—was designed to provide both single and multi-joint assisted training while retaining the advantages of traditional end-effector robots, such as ease of use, compactness and portability, and potential cost-effectiveness (compared to exoskeletons). This work presents the design, optimization, and characterization of AREBO for training single-joint movements of the arm. AREBO has three actuated and three unactuated degrees of freedom, allowing it to apply forces in any arbitrary direction at its endpoint and self-align to arbitrary orientations within its workspace. AREBO’s link lengths were optimized to maximize its workspace and manipulability. AREBO provides single-joint training in both unassisted and adaptive weight support modes using a human arm model to estimate the human arm’s kinematics and dynamics without using additional sensors. The characterization of the robot’s controller and the algorithm for estimating the human arm parameters were performed using a two degrees of freedom mechatronic model of the human shoulder joint. The results demonstrate that (a) the movements of the human arm can be estimated using a model of the human arm and robot’s kinematics, (b) AREBO has similar transparency to that of existing arm therapy robots in the literature, and (c) the adaptive weight support mode control can adapt to different levels of impairment in the arm. This work demonstrates how an appropriately designed end-effector robot can be used for single-joint training, which can be easily extended to multi-joint training. Future work will focus on the evaluation of the system on patients with any neurological condition requiring arm training.

Xuelian injection ameliorates complete Freund's adjuvant-induced acute arthritis in rats via inhibiting TLR4 signaling

BackgroundXuelian injection (XI), a classic preparation extracted from Saussureae Involucratae Herba, has been clinically used to manage rheumatoid arthritis (RA) for nearly twenty years in China. However, the underlying anti-RA mechanism of XI remains unclear. In this study, complete Freund's adjuvant (CFA)-induced acute arthritic model was used to examine the anti-RA effects of XI in vivo. The molecular mechanisms of this action were further investigated using lipopolysaccharide (LPS)-stimulated RAW 264.7 macrophages. MethodsXI and XI freeze dried powder were characterized by UPLC analysis. CD68 and TLR4 expression in the ankle joints was measured by immunohistochemistry. The secretion of inflammatory mediators was detected by ELISA. The expression levels of TLR4 involved components were measured by Western blotting. The localization of transcription factors was measured by immunofluorescence assay. ResultsXI treatment ameliorated arthritic symptoms induced by CFA in the ankle joints of rats. The serum levels of inflammatory mediators, including TNF-α, MCP-1, and Rantes were decreased by XI treatment. The elevation of CD68 and TLR4 levels in ankle joints caused by CFA was suppressed by XI treatment. Moreover, XI treatment inhibited the secretion of nitric oxide and prostaglandin E2 in LPS-treated RAW264.7 macrophages. The expression of their enzymes iNOS and COX-2 was also decreased after XI treatment. The production of inflammatory mediators, including TNF-α, IL-6, IL-1β, MCP-1, MIP-1α, and Rantes was reduced by XI treatment in LPS-stimulated RAW264.7 cells. The phosphorylation of p38, JNK, ERK, TBK1, IKKα/β, IκB, p65, c-Jun, and IRF3 was reduced after XI treatment. Additionally, the expression levels of nuclear proteins of p65, c-Jun, and IRF3 were inhibited by XI treatment. ConclusionsTaken together, XI possesses potential anti-RA effect and the underlying mechanism may be closely associated with the inhibition of TLR4 signaling. Our findings provide further pharmacological justifications for the clinical use of XI in RA treatment.

Correlation of Joint Space Widening on Valgus Stress Magnetic Resonance Imaging With Level of Play and Innings Pitched in Professional Pitchers.

Previous studies have described various techniques and confirmed the clinical utility of valgus stress radiography and stress ultrasound in overhead athletes. The addition of valgus stress and a high-resolution anatomic assessment of the elbow with magnetic resonance imaging (MRI) in the active throwing position (flexed elbow valgus external rotation [FEVER] view) can add valuable diagnostic or prognostic information in throwing athletes. The purpose of this study was to evaluate findings on MRI and subsequent performance in professional throwing athletes. It was hypothesized that joint space widening in the FEVER view would be predictive of performance and the risk of subsequent injuries. Cross-sectional study; Level of evidence, 3. All pitchers on 2 Major League Baseball teams who consented to participate during their preseason screening in 2019 and 2020 underwent standard and FEVER MRI, and performance data from the following season were recorded, including injuries, mean throwing velocity, number of innings pitched, strikeout percentage, walk percentage, weighted on-base average, and level of play reached (not signed, minor league, or major league). Categorical variables were compared using the Fisher exact test or chi-square test, and continuous variables were compared using the Kruskal-Wallis test, as appropriate. Ordered logistic regression was used to determine the independent factors predicting performance. A total of 91 players underwent preseason imaging, and all players had subsequent performance data available. Multivariate analysis revealed that when controlling for age, mean velocity, history of injuries, presence of symptoms, and history of ulnar collateral ligament reconstruction, increased absolute joint space widening was predictive of a lower level of play (β = -0.63; P = .042). Univariate analysis demonstrated a significant correlation between relative joint space widening and level of play reached (β = -0.54; P = .034). Relative joint space widening remained a significant predictor of level of play (β = -0.87; P = .012) on multivariate analysis. Multivariate analysis also showed that both absolute joint space widening (β = -13.50; P = .012) and relative joint space widening (β = -13.60; P = .026) were predictive of the number of innings pitched in the subsequent season. The present study demonstrates that findings on MRI with valgus stress correlated with the level of play reached and number of innings pitched in professional throwing athletes.

A comparative study on the mandatory variation of COVID-19 vaccination policies

Abstract Background Reflection on COVID-19 vaccine policies is critical to understand their effectiveness. Joint level vaccine mandates encouraged by the EU were not adopted by member states, leading to a multitude of vaccine policies that varied in their mandatory nature. We hypothesised that highly mandatory vaccine policies would result in high vaccine uptake & low mandatory polices would result in the opposite, & that differences between countries would impact policy implementation & effectiveness. Methods The mandatory vaccine framework was used to evaluate the mandatory nature of case study countries’ COVID-19 vaccine policies from 2020-23. France, Italy, Sweden, Poland, & Romania were chosen to represent a cross-section of economies, health systems, political histories, & COVID-19 experiences. Data was sourced from the ECDC's COVID-19 Data Tracker, government documents, media reports, & peer reviewed studies. Results Highly mandatory vaccine policies lead to higher overall vaccine uptake, as found in France 92.3% & Italy 89.8%. However, highly mandatory policies may cause social disruption & increase mistrust in vaccinations & governments, as seen in France. Moderate to low mandatory policies had mixed results. Romania & Poland had low vaccine uptake below the EU average. Additionally, low mandatory policies risk higher death & case rates & did not increase social acceptance of vaccination or avoid vaccine related social disruption, as seen in Poland. Sweden presents contrasting findings, reporting vaccine uptake of 86.2%, 13.1% above EU average despite their low mandatory policies, contradicting the hypothesis. Conclusions The research provides insights into vaccine policy decision making under the pressure of pandemic conditions, & the potential consequences of implementing various severity & enforcement levels within vaccine policies. The study demonstrates the need to develop pandemic vaccine framework to aid policymakers during disease crises. Key messages • The research highlights that it is essential that policy makers adopt cultural and health system appropriate vaccination policies for the populations they are targeting to vaccinate. • The variation of vaccine uptake between member states also stresses the importance for the EU to take a more central role in health policy.

Association of Interosseous Tendon Inflammation in the Hand With Different Early Arthritides in a 10-Year Magnetic Resonance Imaging Study.

Inflammation around the tendons of the hand interosseous muscles (interosseous tendon inflammation [ITI]) was recently identified on magnetic resonance imaging (MRI) in a set of patients with rheumatoid arthritis (RA) and arthralgia. We conducted a large MRI study to assess the prevalence of ITI at diagnosis of RA and of other arthritides, as well as its relationship with clinical signs. A total of 1,205 patients presenting with various types of early arthritis between 2010 and 2020 underwent contrast-enhanced hand MRI as part of the prospective Leiden Early Arthritis Cohort. MRI was evaluated with blinding for clinical data, for ITI lateral of metacarpophalangeal (MCP) joints 2-5, and for synovitis/tenosynovitis/osteitis. We assessed ITI presence at baseline per diagnosis and its relationship with clinical characteristics (ie, presence of hand arthritis, increased acute phase reactants, and local joint swelling and tenderness). Logistic regression and generalized estimating equations were used with adjustment for age and established local inflammation features (synovitis/tenosynovitis/osteitis). A total of 36% of patients with early RA (n=532) had ITI; this was similar in patients with anti-citrullinated protein antibody (ACPA)-negative RA (37%) and those with ACPA-positive RA (34%; P = 0.53). ITI occurred regularly in remitting seronegative symmetrical synovitis with pitting edema (60%) and connective tissue diseases (44%) and less frequently in undifferentiated arthritis (14%), psoriatic arthritis (14%), inflammatory osteoarthritis (8%), reactive arthritis (7%), crystal arthritis (7%), and peripheral spondylarthritis (4%). ITI occurred more often in diagnoses with frequent arthritis of the hands (P < 0.001) and increased acute-phase reactants (P < 0.001). Within RA, ITI occurred together with local MCP joint synovitis (odds ratio [OR] 2.4, 95% confidence interval [95% CI] 1.7-3.4), tenosynovitis (OR 2.4, 95% CI 1.8-3.3), and osteitis (OR 2.2, 95% CI 1.6-3.1) on MRI. Moreover, ITI presence was associated with local MCP joint tenderness (OR 1.6, 95% CI 1.2-2.1) and swelling (OR 1.8, 95% CI 1.3-2.6), independent of age and MRI-detected synovitis/tenosynovitis/osteitis. ITI occurs regularly in RA and other arthritides with preferential involvement of hand joints and increased acute-phase reactants. At the MCP joint level, ITI associates independently with joint tenderness and swelling. Hence, ITI is a newly identified inflamed tissue mainly found in arthritides with particularly extensive and symptomatic inflammation.

Emotion recognition by skeleton-based spatial and temporal analysis

This study introduces an automatic emotion recognition system (AER) focusing on skeletal-based kinematic datasets for enhanced human–computer interaction. Departing from conventional approaches, it achieves real-time emotion recognition in real-life situations. The dataset covers seven emotions and undergoes assessment by eight diverse machine and deep learning algorithms. A thorough investigation is undertaken by varying window sizes and data states, including raw positions and feature-extracted data. The findings imply that incorporating advanced techniques like joint-related feature extraction and robust classifier models yields promising outcomes. Dataset augmentation via varying window sizes enriches insights into real-world scenarios. Evaluations exhibit classification accuracy surpassing 99% for small windows, 94% for medium, and exceeding 88% for larger windows, thereby confirming the robust nature of the approach. Furthermore, we highlight window size's impact on emotion detection and the benefits of combining coordinate axes for efficiency and accuracy. The analysis intricately examines the contributions of features at both the joint and axis levels, assisting in making well-informed selections. The study's contributions include carefully curated datasets, transparent code, and models, all of which ensure the possibility of replication. The paper establishes a benchmark that bridges theory and practicality, solidifying the proposed approach's effectiveness in balancing accuracy and efficiency. By pioneering advanced AER through kinematic data, it sets a new standard for efficacy while driving seamless human–computer interaction through rigorous analysis and strategic design.

Contribution to the study of stresses in the thumb column during key pinch grip

ObjectivesThe aim of this study was to calculate the stress acting on the trapeziometacarpal joint during an key pinch grip. MethodWe used profile X-rays of the thumb to measure the various bony and muscle lever arms. We assessed the angles of action of the muscular elements involved in the thumb column. Based on this data, we established a two-dimensional geometric model that enabled us to determine the forces at each joint level, as a function of stresses and muscular contributions. We were also able to calculate the participation of the different muscle groups in obtaining a balanced situation. ResultsOur results, as a function of the degree of flexion of the interphalangeal and metacarpophalangeal joints, show a multiplying factor of 2.9–3.19 in relation to the key pinch grip force. DiscussionPrevious studies modelling a key pinch grip are showed multiplying factors from 6 to 13 in relation to the key pinch grip force. They are not compatible with the characteristics of the polyethylene used for trapeziometacarpal prostheses, whereas numerous articles in the literature show survival rates that are more or less comparable to those of total hip prostheses. These studies required an excessive number of assumptions, which could lead to error. Our results are compatible with the results of trapeziometacarpal prosthesis and with those of a recent study measuring intra-articular trapeziometacarpal pressure in a cadaveric model. Our model allows us to test different configurations of the thumb spine depending on the degree of flexion of the interphalangeal and metacarpophalangeal joints.

A Novel Ultrasonographic Method to Detect Intra-Operative Syndesmotic Malreduction – the “Gap Penetrance” Sign

Category: Ankle; Other Introduction/Purpose: Anatomical reduction of the distal syndesmosis can be challenging. There is ongoing debate and variability in the methods used for evaluating the accuracy of reduction, including radiography, intra-operative CT, arthroscopy, and direct visualization. Tornetta et al. have described a method called ‘the articular surface method’ that evaluates the relationship between the articular cartilage of the distal anteromedial fibula and the anterolateral tibia as being significantly more accurate for detecting malreduction. However, it entails an additional surgical incision over the distal aspect of the ankle. The aim of this study was to find a non-invasive method using ultrasound to assess the accuracy of reduction in syndesmotic injuries. Methods: A cadaveric syndesmotic instability model was created by dissecting the PITFL, IOL, and AITFL through a small posterior incision. The fibula was fixed in incremental degrees of rotational malreduction to achieve a malreduction of 3, 5, and 7 mm. A blinded observer assessed the syndesmosis using a portable ultrasound device. The probe was placed in its short axis at the level of the ankle joint then moved proximally until both the anteromedial fibular and anterolateral tibial articular surfaces were visualized simultaneously in one view. In a reduced syndesmosis, the distal articular surfaces of the tibia and fibula overlap. This relationship is altered in a malreduced syndesmosis, which allows ultrasonographic waves to ‘penetrate’ through the malreduced articular surfaces and be readily detected. This sign was graded positive if an acoustic signal penetrated between the distal articular surfaces of the tibia and fibula, and negative if no acoustic signal was detected. Results: The gap penetrance sign was positive in all 3 instances of malreduced syndesmoses, and negative in an anatomically reduced syndesmosis. Figure 1 illustrates the outcomes in a reduced syndesmosis and malreduced syndesmosis, respectively. Conclusion: We introduced a novel sign that can be used as a surrogate of the ‘articular surface method’ to detect syndesmotic malreduction. It is accurate, can obviate the need for a separate surgical incision for direct visualization, permits rapid point-of- care evaluation in the operating room, and minimizes radiation exposure

Biomechanical Evaluation of 4th Generation Minimally Invasive Distal First Metatarsal Osteotomy-Akin Osteotomy Technique on First Ray Articular Contact Properties

Category: Bunion; Basic Sciences/Biologics Introduction/Purpose: Hallux valgus is a common deformity encountered, but remains a complex clinical entity. Fourth generation minimally invasive (MIS) techniques consisting of a percutaneous distal metatarsal transverse osteotomy combined with an Akin osteotomy have been utilized to address mild to severe hallux valgus deformities. Benefits of a MIS approach include improved cosmesis, faster recovery, lower opiate requirement, immediate weightbearing, and favorable outcomes relative to a traditional, open procedure. An understudied area with respect to hallux valgus correction is the effect that osteotomies can have on the articular contact properties of the first ray following correction. Methods: Sixteen paired cadaveric specimens were dissected to include the first ray and tested in a customized apparatus. Specimens were randomized to receive a distal transverse osteotomy translated either 50% or 100% of the width of the first metatarsal shaft. The osteotomy was performed with either a 00or 200 distal angulation of the burr relative to the shaft in the axial plane. Specimens were tested in the intact state and following the distal first metatarsal osteotomy for peak pressure, contact area, contact force and center of pressure at the first metarsophalangeal joint (MTP) and first tarsometatarsal joint (TMT). An Akin osteotomy was then performed on each specimen and peak pressure, contact area, contact force and center of pressure were recalculated. Results: There was a notable decrease in peak pressure, contact area, and contact force across the TMT joint with greater shifts of the capital fragment. However, at 100% translation of the capital fragment, distal angulation of the osteotomy by 200 appears to improve loading across the TMT joint. Addition of the Akin osteotomy at 100% translation also aids in increasing the contact force across the TMT joint. The MTP joint is less sensitive to changes in shifts and angulation of the capital fragment. The Akin osteotomy also leads to increased contact force across the MTP joint when the capital fragment is translated 100%. Conclusion: While the clinical significance is unknown, larger shifts of the capital fragment lead to greater load alterations at the level of the TMT joint than the MTP joint. Distal angulation of the capital fragment and the addition of an Akin osteotomy can aid in reducing the size of those changes. The Akin can lead to increased contact forces at the MTP joint with 100% translation of the capital fragment.

A Novel Exoskeleton Design and Numerical Characterization for Human Gait Assistance

This paper addressed attention to the design of a new lower limb exoskeleton that can be used for human gait assistance as based on kinematic considerations. The designed leg exoskeleton had on its own structure a combination of three mechanism types, namely a Chebyshev mechanism, a pantograph, and a Stephenson six-bar mechanism. The design core focused on inserting the Stephenson six-bar bar mechanism in order to obtain an imposed motion at the ankle joint level. Numerical simulations of the designed lower limb exoskeleton have been developed and the obtained results demonstrate the engineering feasibility of the proposed prototype, with a characterization of satisfactory operation performance.

Weight-bearing line at the ankle joint level shifted laterally after total knee arthroplasty for varus knee osteoarthritis: Evaluation of the hip-to-calcaneus line

BackgroundFew studies have comprehensively examined how alignment beyond the ankle joint changes after Total knee arthroplasty (TKA). This retrospective study aimed to answer the questions: (1) do the radiological parameters beyond the ankle joint, including the weight-bearing line at the ankle joint level, change after TKA in varus knee osteoarthritis? (2) Does the lower extremity alignment correlate with alignment beyond the ankle joint? HypothesisOur hypothesis was that TKA altered the radiological parameters beyond the ankle, which correlated with the lower extremity alignment. Patients and methodsThis retrospective study included 67 patients who underwent mechanically aligned TKA for varus knee osteoarthritis. The hip-knee-ankle angle (HKA), tibial plafond inclination angle (TPIA), hindfoot alignment angle (HA), talar tilt (TT), and weight-bearing line at the ankle joint level (mechanical ankle joint axis point [MAJAP]) were measured using radiographs taken before and 6 months after TKA; each parameter was compared between the two time points. The correlations between HKA and other parameters were examined preoperatively and postoperatively. ResultsThe mean HKA, TPIA, HA, TT, and MAJAP changed significantly after TKA from 15.0±6.1̊ to 2.6̊±3.5̊, from 10.8̊±5.7̊ to 4.7̊±3.9̊, from 2.3̊±5.5̊ to –2.5̊±4.5̊, from 0.2̊±1.3̊ to –0.5̊±1.4̊, and from 29.3±23.3 to 54.3±20.6, respectively. Correlations were noted between the preoperative HKA and the preoperative TPIA (r=0.58), HA (r=0.36), and MAJAP (r=–0.59), and between the postoperative HKA and the postoperative TPIA (r=0.54) and MAJAP (r=–0.38). DiscussionTKA for varus knee osteoarthritis altered radiological parameters beyond the ankle, with the weight-bearing line at the ankle joint level passing more laterally. The weight-bearing line at the ankle joint level was correlated with lower extremity alignment both preoperatively and postoperatively. Level of evidenceIV; single-centre retrospective observational study.

Risk factors for burn contractures: A cross-sectional study in a lower income country

Risk factors for burn contractures require further study, especially in low and middle-income countries (LMICs); existing research has been predominantly conducted in high income countries (HICs). This study aimed to identify risk factors for burn contractures of major joints in a low-income setting. Potential risk factors (n = 104) for burn contracture were identified from the literature and a survey of clinicians with extensive experience in low and middle-income countries (LMIC). An observational cross-sectional study of adult burn survivors was undertaken in Bangladesh to evaluate as many of these risk factors as were feasible against contracture presence and severity. Forty-eight potential risk factors were examined in 48 adult patients with 126 major joints at risk (median 3 per participant) at a median of 2.5 years after burn injury. Contractures were present in 77% of participants and 52% of joints overall. Contracture severity was determined by measurement of loss of movement at all joints at risk. Person level risk factors were defined as those that were common to all joints at risk for the participant and only documented once, whilst joint level risk factors were documented for each of the participant’s included joints at risk. Person level risk factors which were significantly correlated with loss of range of movement (ROM) included employment status, full thickness burns, refusal of skin graft, discharged against medical advice, low frequency of follow up and lack of awareness of contracture development. Significant joint level risk factors for loss of ROM included anatomical location, non-grafted burns, and lack of pressure therapy. This study has examined the largest number of potential contracture risk factors in an LMIC setting to date. A key finding was that risk factors for contracture in low-income settings may differ substantially from those seen in high income countries, which has implications for effective prevention strategies in these countries. Better whole person and joint outcome measures are required for accurate determination of risk factors for burn contracture. Recommendations for planning and reporting on future contracture risk factor studies are made.

Forearm injury reconstruction with split-thickness skin graft: a case report

Nowadays, automobile accidents have become one of the leading causes of death and functional, as well as aesthetic, repercussions in the young population. These accidents often result in a significant loss of skin surface, posing a challenge for reconstructive surgeons to cover the wounds. As a result, in the last few decades, various techniques such as negative pressure therapy, partial and full-thickness skin grafts, and the use of different flaps have been implemented. This article aims to discuss the use of skin grafts for wound coverage and the differences between the two types of grafts. It will also present a case study of a 43-year-old patient who suffered trauma while driving his vehicle, resulting in an injury to his left forearm's posterior region from the level of the elbow joint to 6 cm proximal to the radiocarpal joint. The wound was covered with a partial-thickness skin graft, which showed good evolution and excellent aesthetic results.

Strength and crack resistance of cement composites under multilevel reinforcement

The working hypothesis is confirmed that the required fracture toughness of structural concrete can be provided by multi-level reinforcement: at the level of the crystalline joint of cement stone – carbon nanotubes, and at the level of fine-grained concrete – various macro-sized fiber fibers (steel, polymer). Reinforcement of a crystalline splice with carbon nanotubes leads to an increase in tensile strength by 20 %, an increase in Young’s modulus. With dispersed reinforcement of concrete modified with nanoparticles at the level of fine-grained concrete, the tensile strength increases by 109 %, the critical stress intensity coefficient (crack resistance index) increases by 280 % at normal separation, and by 48 % at transverse shear.

Wrapped Composite Joints for Circular Hollow Section Structures

AbstractAn innovative bonding joining technology for truss/lattice circular hollow section (CHS) supporting structures is being developed as replacement for welded joints. Wrapped Composite Joint uses bonding instead of welding to transfer the joint forces and bending moments between the chord and brace CHS members through a dedicated fibre reinforced polymer composite wrap. It is aimed to replace all welds in different types of joints such as X, K, KK and splice joints in fatigue and/or corrosion dominated designs of truss/lattice structures such as offshore wind jackets and floaters, fish farms, truss bridges, etc. Composite material is known for good fatigue performance from aerospace industry and wind turbine blades. Number of joint experiments showed superior fatigue performance of the wrapped composite joints compared to welded CHS joints. This new concept allows for huge reduction of thickness of CHS members resulting in significant truss/lattice structure weight reduction and increase of fatigue lifetime. This paper presents state of development and outlook of the wrapped composite joint technology in terms of design, production and joint performance for ultimate limit state, fatigue and influence of the environment. Framework of prediction methods and design principles based on ongoing experimental and numerical research will be presented. The scope includes material, interface, and joint level experiments from small to full scale (100‐600 mm member diameter) and finite element modeling of complex steel‐composite bonded joints. Advantage of using state‐of‐the‐art monitoring techniques such as Digital Image Correlation, Fibre Optics Strain Measurement and 3D scanning is highlighted

Uncertainty-aware automated assessment of the arm impedance with upper-limb exoskeletons.

Providing high degree of personalization to a specific need of each patient is invaluable to improve the utility of robot-driven neurorehabilitation. For the desired customization of treatment strategies, precise and reliable estimation of the patient's state becomes important, as it can be used to continuously monitor the patient during training and to document the rehabilitation progress. Wearable robotics have emerged as a valuable tool for this quantitative assessment as the actuation and sensing are performed on the joint level. However, upper-limb exoskeletons introduce various sources of uncertainty, which primarily result from the complex interaction dynamics at the physical interface between the patient and the robotic device. These sources of uncertainty must be considered to ensure the correctness of estimation results when performing the clinical assessment of the patient state. In this work, we analyze these sources of uncertainty and quantify their influence on the estimation of the human arm impedance. We argue that this mitigates the risk of relying on overconfident estimates and promotes more precise computational approaches in robot-based neurorehabilitation.

Performance degradation by column foot damage: From column foot joints to frames

This study investigated the performance degradation brought by column foot damage on both joint level and frame level. Three column foot joint specimens, characterized by different damage indexes (defined as the ratio of absent sectional width to radius), were cyclically tested. Typical deformation modes of the damaged joints were identified. Mechanical behavior degradation of the joint specimens was quantified. The influence of the column foot damage on a traditional timber frame’s lateral performance was further analyzed. The test indicated that the column foot damage decreased the uplift deformation of a column during the rotation of a column foot joint. Both the mechanical performance of a column foot joint and the frame was approximately linearly degraded by the column foot damage. With a damage index of 0.6, the joints’ initial rotational stiffness and moment-resisting capacity decreased 40 %; the elastic lateral stiffness, the peak load and the cumulative energy dissipation of the frame reduced 31 %, 20 % and 11 %, respectively. Varying the column dimensions did not considerably change the degradation pattern in the elastic stiffness and cumulative energy dissipation of the frame. However, changing the column diameter significantly influenced the damage impact tendency on the lateral load-resisting capacity of the frame. Specifically, with a 30 % variation in the column diameter, the degradation of the column foot damage on the peak load ranged from 12 % to 30 %.

Comparison of ligamentum flavum thickness between central and lateral lesions in a patient with central lumbar spinal canal stenosis.

Thickened ligamentum flavum has been considered as a major cause of central lumbar spinal canal stenosis (CLSCS). Previous studies have demonstrated that ligamentum flavum thickness (LFT) is correlated with aging, degenerative spinal stenosis, and disc degeneration. Thus, hypertrophy of the ligamentum flavum is a major cause of CLSCS, and measurement of LFT has been considered a morphologic parameter in the diagnosis of CLSCS. To our knowledge, comparison of LFT between central and lateral lesions has not been reported. In addition, no research has analyzed best clinical cutoff values of central ligament flavum thickness (CLFT) and lateral ligament flavum thickness (LLFT). This study aimed to compare CLFT with LLFT in patients with CLSCS and further compare the CLFT and LLFT findings between the 2 groups to analyze LFT variation. Both CLFT and LLFT samples were collected from 101 participants with CLSCS and from 103 participants in the control group who underwent lumbar magnetic resonance imaging without evidence of CLSCS. Axial T2-weighted lumbar magnetic resonance scans were acquired at the L4 to 5 facet joint level from each participant. Average CLFT value was 2.25 ± 0.51 mm in the control group and 4.02 ± 0.74 mm in the CLSCS group. Average LLFT value was 2.50 ± 0.51 mm in the control group and 3.38 ± 0.66 mm in the CLSCS group. CLSCS patients had significantly higher CLFT and LLFT (both P < .001). Regarding the validity of both CLFT and LLFT as predictors of CLSCS, a receiver operating characteristic estimation revealed that the most suitable cutoff value for CLFT was 3.10 mm, with sensitivity of 95.0%, specificity of 94.2%, and an area under the curve of 0.97. The best cut-off value of LLFT was 2.92 mm, with sensitivity of 78.2%, specificity of 77.7%, and area under the curve of 0.87. We have 4 important new findings: The mean CLFT is significantly lower than that of the mean LLFT in the normal control group; CLFT and LLFT are both significantly associated with CLSCS; Increase rate of CLFT is faster than that of LLFT in the CLSCS group; and CLFT is a more sensitive measurement parameter to predict CLSCS than LLFT.

Real-world apremilast use in biologic-naïve psoriatic arthritis patients. Data from Spanish clinical practice

IntroductionApremilast is approved for treatment of psoriasis and psoriatic arthritis (PsA). Real-world evidence on apremilast effectiveness in clinical practice is limited. MethodsObservational study enrolling adult patients, across 21 Spanish centres, who had initiated apremilast in the prior 6 (±1) months and were biologic naive. Data were collected at routine follow-up visits 6 and 12 months after apremilast initiation. Primary outcome was 6 and 12-month persistence to apremilast. Secondary outcomes included Disease Activity for PsA (DAPSA), joint erosions, enthesitis, dactylitis, and patient-reported quality of life (QoL, measured using the PsA impact of disease [PsAID] questionnaire). ResultsWe included 59 patients. Most had oligoarticular PsA, moderate disease activity, and high comorbidity burden. Three-quarters were continuing apremilast at 6 months and two-thirds at 12 months; mean (SD) apremilast treatment duration was 9.43 (1.75) months. DAPSA scores showed improved disease activity: one-third of patients in remission or low activity at apremilast initiation versus 62% and 78% at 6 and 12 months, respectively. Eleven of 46 patients with radiographic assessments had joint erosions at apremilast initiation and none at month 12. Median (Q1, Q3) number of swollen joints was 4.0 (2.0, 6.0) at apremilast initiation versus 0.0 (0.0, 2.0) at 12 months. Incidence of dactylitis and enthesitis decreased between apremilast initiation (35.6% and 28.8%, respectively) and month 12 (11.6% and 2.4%, respectively). Over two-thirds of patients had a PSAID-9 score <4 (cut-off for patient-acceptable symptom state) at month 12. ConclusionsIn Spanish clinical practice, two-thirds of PsA patients continued apremilast at 12 months, with clinical benefits at the joint level, no radiographic progression of erosions, and a positive impact on patient-reported QoL.Trial registration number Clinicaltrials.gov: NCT03828045.