Effect of novel polyethylene insert configurations on bone-implant micromotion and contact stresses in total ankle replacement prostheses: a finite element analysis.

Purpose: This study investigates the impact of elastic improvements to the artificial ankle joint insert on prosthesis biomechanics to reduce the risk of prosthesis loosening in TAR patients. Methods: CT data of the right ankle was collected from one elderly female volunteer. An original TAR model (Model A) was developed from CT images and the INBONE II implant system. The development of the new inserts adopts an elastic improvement design approach, where different geometric configurations of flexible layers are inserted into the traditional insert. The structure can be divided into continuous flexible layers and intermittent flexible layers. The flexible layers aim to improve the elasticity of the component by absorbing and dispersing more kinetic energy. The newly designed inserts are used to replace the original insert in Model A, resulting in the development of Models B-D. A finite element model of gait analysis was based by gait parameters. Discrepancies in micromotion and contact behaviour were analysed during the gait cycle, along with interface fretting and articular surface stress at 50% of the gait cycle. Results: In terms of micromotion, the improved elastic models showed reduced micromotion at the tibial-implant interfaces compared to the original model. The peak average micromotion decreased by 12.1%, 13.1%, and 14.5% in Models B, C, and D, respectively. The micromotion distribution also improved in the improved models, especially in Model D. Regarding contact areas, all models showed increased contact areas of articular surfaces with axial load, with Models B, C, and D increasing by 26.8%, 23.9%, and 24.4%, respectively. Contact stress on articular surfaces increased with axial load, reaching peak stress during the late stance phase. Models with continuous flexible layer designs exhibited lower stress levels. The insert and the talar prosthetic articular surfaces showed more uniform stress distribution in the improved models. Conclusion: Improving the elasticity of the insert can enhance component flexibility, absorb impact forces, reduce micromotion, and improve contact behavior. The design scheme of continuous flexible layers is more advantageous in transmitting and dispersing stress, providing reference value for insert improvement.

Do disease-modifying antirheumatic drugs and non-steroidal anti-inflammatory drugs increase the burden on ankylosing spondylitis patients with mild-moderate COVID-19? evidence from a retrospective cohort study.

Objectives: The impact of non-steroidal anti-inflammatory drugs (NSAIDs), conventional synthetic disease-modifying antirheumatic drugs (csDMARDs) and tumor necrosis factor inhibitors (TNFi) on the outcomes of mild-moderate COVID-19 in patients with ankylosing spondylitis (AS) remains unclear. This study aimed to evaluate the effects of NSAIDs, csDMARDs, and TNFi on AS patients with mild-moderate COVID-19. Methods: This cohort study utilized patient-reported PCR/antigen tests to determine the occurrence of COVID-19 and assessed clinical manifestations to determine its severity. The study focused on two primary outcomes: an increased number of COVID-19 symptoms and a prolonged disease course (longer than 10 or 28 days). Modified Poisson regression was performed to analyze the association between exposures and outcomes. Results: A total of 521 patients were included in the analysis. The median age was 34.8 (inter-quartile range: 27.2-46.7), with 420 (80.6%) being men. Among the patients, 52 (10.0%) had comorbidities and 443 (85%) had been vaccinated. After adjusting for confounding factors, there was no significant association between csDMARDs or TNFi and the presence of more than 5 symptoms in mild-moderate COVID-19 (adjusted relative risk (RRa) 1.08, 95% CI: 0.84-1.40 or 1.09, 0.92-1.29 for csDMARDs or TNFi, respectively), whereas the prevalence of experiencing more than 5 symptoms increased in patients with NSAID monotherapy (RRa 1.22, 95% CI: 1.01-1.46). Similarly, there was no significant association with having more than 10 symptoms (RRa 0.65, 95% CI: 0.26-1.64; 0.95, 0.36-2.54; and 1.01, 0.53-1.91 for NSAIDs, csDMARDs, and TNFi, respectively). Patients who had pre-existing use of NSAIDs, csDMARDs and TNFi had similar odds of experiencing a disease course longer than 10 days (RRa 1.17, 95% CI: 0.82-1.66; 1.18, 0.78-1.77; and 1.22, 0.92-1.63 for NSAIDs, csDMARDs, and TNFi, respectively) and longer than 28 days (RRa 0.94, 95% CI: 0.31-2.81; 0.97, 0.25-3.74 and 1.05, 0.44-2.49, respectively) compared to those not using medication. Conclusion: AS patients treated with csDMARDs or TNFi did not show inferior outcomes in terms of symptom burden or recovery compared to those not using medication in mild-moderate COVID-19. The observed inverse association between pre-existing NSAIDs use and COVID-19 symptom burden in AS deserves further investigation.

Cigarette Smoking Increases the Prevalence of Hip Joint Involvement in Ankylosing Spondylitis: A Real-World Case-Control Study.

OBJECTIVE: To investigate the association between cigarette smoking and hip joint involvement in ankylosing spondylitis (AS). METHODS: This case-control study compared patients with AS with and without hip involvement, as defined by the Bath Ankylosing Spondylitis Radiology Hip Index. Logistic regression analysis, subgroup analysis, and sensitivity analysis were conducted to estimate the association between smoking and hip involvement in AS. RESULTS: This study included 103 patients with hip involvement (cases) and 89 patients without hip involvement (controls). In univariate analysis, patients who had juvenile-onset AS (JAS), were younger, were male, had peripheral arthritis history, or had cigarette exposure were prone to hip involvement. After adjusting for confounding factors, JAS (adjusted odds ratio [aOR] 2.52, 95% CI 1.26-5.06), male sex (aOR 2.89, 95% CI 1.14-7.33), and cigarette smoking (aOR 7.23, 95% CI 2.27-23.05) were regarded to be independently associated with hip involvement in AS. Moreover, patients who smoked with exposure of less than 10 pack-years were 2.2 times more likely to have hip involvement than those without (aOR 2.21, 95% CI 1.09-4.47). This association was reproduced in subgroup analyses of males and propensity score-matched subjects, and it withstood sensitivity analysis. CONCLUSION: Smoking is a novel independent risk factor for hip involvement in AS; even exposure of less than 10 pack-years could contribute to increased prevalence of hip involvement in AS, which underlines the significance of smoking cessation in patients with AS, especially for JAS.

Tai Chi exercise can ameliorate physical and mental health of patients with knee osteoarthritis: systematic review and meta-analysis.

OBJECTIVE: To systematically review the effects of Tai Chi exercise as a nonpharmacological therapeutic strategy on the physical and mental health in individuals with knee osteoarthritis. DATA SOURCES: A systematic literature retrieval has been conducted in PubMed, Web of Science, EMbase, CENTRAL, OVID, CINAHL, Physiotherapy Evidence Database, Chinese Biomedical Database and China National Knowledge Infrastructure up to June 2020 to identify the relevant randomised controlled trials (RCTs). METHODS: Two authors assessed independently the risk of bias using the Cochrane Collaboration's tool. Standardised mean difference (SMD) and 95% CI were calculated and data were combined using the fixed or random-effect model. The strength of evidence was rated with Grading of Recommendations Assessment, Development and Evaluation (GRADE) system. RESULTS: A total of 16 RCTs involving 986 patients with knee osteoarthritis met the established inclusion criteria. The strength of evidence for the main outcomes was low or moderate. The systematic review illustrated the efficacy of Tai Chi exercise in treating and managing knee osteoarthritis. Patients' outcomes practising Tai Chi exercise were improved significantly, including pain (SMD = ‒0.69, 95%CI: ‒0.95 to ‒0.44, P < 0.001), stiffness (SMD = ‒0.59, 95%CI: ‒0.91 to ‒0.27, P < 0.001), physical function (SMD = ‒0.92, 95%CI: -1.16 to ‒0.69, P < 0.001), dynamic balance (SMD = 0.69, 95%CI: 0.38 to 0.99, P < 0.001), physiological and psychological health (SF-36 PCS: SMD = 0.48, 95%CI: 0.28 to 0.68, P < 0.001; SF-36 MCS: SMD = 0.26, 95%CI: 0.06 to 0.45, P = 0.01). No adverse events associated with Tai Chi exercise were reported. CONCLUSION: Tai Chi exercise was beneficial for ameliorating physical and mental health of patients with knee osteoarthritis and should be available as an alternative non-pharmacological therapy in rehabilitation programmes.

Effects of types and degrees of ankylosing spondylitis hip structural damages on post-total hip arthroplasty outcome measurements.

To determine the effects of ankylosing spondylitis (AS)-associated hip damages on the outcome measurements after total hip arthroplasty (THA).The medical records of 122 patients with AS (181 hips) who underwent THA were retrospectively reviewed. The mean follow-up was 43.9 (32-129) months. The types and degrees of hip damages were evaluated by preoperative hip X-rays. The patients were grouped according to the satisfaction degree after the operation. Univariable and multivariable statistical analyses were conducted.The intraclass correlation coefficients for the assessment between the 2 reviewers in the study were 0.86 to 0.97. Cox regression showed that femoral head erosion severity had an effect on the recovery time of independent walking without crutches postoperatively (odds ratio = 1.467, 95% confidence interval: 1.050-2.409, P = .025). The mean time to recover independent walking in the severe femoral head erosion group was 7.3 ±â€Š0.9 weeks, which was 4.6 ±â€Š0.4 weeks longer than in the non-severe femoral head erosion group, as confirmed by the log-rank (Mantel-Cox) test (Chi-squared = 11.684, P = .001). The multivariable analysis showed that higher acetabular sclerosis scores correlated with lower postoperative dissatisfaction risk (odds ratio = 0.322, 95% confidence interval: 0.136-0.764). The multiple linear regression analysis showed that postoperative range of motion (ROM) improvement was affected by preoperative ROM of the hip, space narrowing degree, and ceramic-ceramic material for the weight-bearing surface (F = 179.81, P < .001), with preoperative ROM of the hip having the greatest impact.Severe femoral head erosion prolongs the recovery time of independent walking after THA. Acetabular sclerosis is not associated with poor outcomes in patients with AS-associated hip damage undergoing THA.

Add-On Effects of Conventional Synthetic Disease-Modifying Anti-Rheumatic Drugs in Ankylosing Spondylitis: Data from a Real-World Registered Study in China.

BACKGROUND The aim of this study was to investigate the effects of conventional synthetic disease-modifying anti-rheumatic drugs (csDMARDs) on patients with ankylosing spondylitis (AS) using real-world data, and to analyze patients' choices of csDMARDs and reasons for discontinuation. MATERIAL AND METHODS This observational study included 320 patients satisfying the modified New York criteria for AS. Patients were grouped according to medication: Group 1: 122 patients receiving non-steroidal anti-inflammatory drug (NSAID) monotherapy; Group 2: 198 patients receiving csDMARDs and NSAIDs. Patients were followed for 18 months at 6-month intervals. The change in AS Disease Activity Score and C-reactive protein (ASDAS-CRP) at each visit was the primary outcome. Secondary outcomes were based on validated disease activity questionnaires, clinical assessment, and acute-phase biomarkers (CRP and erythrocyte sedimentation rate [ESR]). Inter-group relationships were assessed across the 18-month follow-up period using generalized additive mixed models. RESULTS Sulfasalazine and thalidomide were the most commonly used csDMARDs, with cumulative use times of 8.9±4.1 months and 9.1±4.7 months, respectively. In Group 2, 56 patients discontinued or switched csDMARDs during the follow-up period, with lack of efficacy being the primary reason. The ASDAS-CRP was found to decrease significantly in both groups; however, improvements in many parameters (including ASDAS-CRP, disease activity questionnaires and ESR) were greater in Group 2. CONCLUSIONS Use of csDMARDs can improve disease activity in terms of ASDAS-CRP. The addition of csDMARDs may provide increased benefits compared with NSAID monotherapy, particularly in the reduction of AS disease activity, in the Chinese population.

Improvement of Disease Management and Cost Effectiveness in Chinese Patients with Ankylosing Spondylitis Using a Smart-Phone Management System: A Prospective Cohort Study.

OBJECTIVES: Ankylosing spondylitis (AS) is a chronic disease that decreases mobility, function, and quality of life. This study introduced the "Smart-phone SpondyloArthritis Management System" (SpAMS), an interactive mobile health (mHealth) tool designed for AS/spondyloarthritis (SpA) disease management and used SpAMS data to evaluate clinical characteristics of Chinese patients with AS. METHODS: SpAMS integrates patient's and physician's portals in a smart phone application. The Chinese Ankylosing Spondylitis Prospective Imaging Cohort was launched using SpAMS in April 2016. Patient self-assessments were completed online at baseline and at every subsequent clinic visit. Physician-reported assessments and treatments were recorded by rheumatologists during each visit. RESULTS: In total, 1201 patients with AS [mean (SD) age, 30.6 (8.7) years; male, 82.6%] were recruited. Mean (SD) disease duration was 8.4 (6.1) years. Past or current symptoms of acute anterior uveitis (AAU), psoriasis, and inflammatory bowel disease (IBD) were observed in 21.0%, 3.7%, and 9.4% of patients, respectively. AAU and IBD occurred significantly more in patients with symptom duration > 10 years. The most commonly used medications at baseline were nonsteroidal anti-inflammatory drugs (98.2%). Patients using tumour necrosis factor inhibitors accounted for 20.8%, and 66.4% of patients used conventional synthetic disease-modifying antirheumatic drugs. At baseline, 57.2% of patients had inactive disease (ID)/low disease activity (LDA); this rate significantly improved to 79.2% after a mean follow-up of 13.3 (5.9) months. Compared with relapsed patients, new achievers of ID/LDA underwent more online patient assessments (P < .001). Problems solved in SpAMS caused 29.1% of clinic visits to a tertiary hospital unnecessary. SpAMS saved an average of 5.3 hours and 327.4 RMB per person on traffic expenses; these expenses equalled 16% of the Chinese monthly disposable personal income. CONCLUSIONS: SpAMS is a time- and cost-saving disease management tool that can help patients with AS perform self-management and provide valuable data to clinicians.

Effectiveness of Subcutaneous Tumor Necrosis Factor Inhibitors in Patients With Ankylosing Spondylitis: A Real-World Prospective Observational Cohort Study in China.

Objective: This prospective observational study investigated the efficacy of tumor necrosis factor inhibitors (TNFis) on disease activity, physical functionality, and mobility in patients with ankylosing spondylitis (AS) in a real-world setting. Methods: The Chinese Ankylosing Spondylitis Prospective Imaging Cohort (CASPIC) is an ongoing cohort study. Patients with AS were included to one of two groups: the TNFi user group included those who received TNFi at any time point; the non-TNFi user group included those who did not receive TNFi. Disease activity, physical functionality, and mobility were assessed by AS Disease Activity Scores (ASDAS), Bath AS Functional Index (BASFI), and Bath AS Metrology Index (BASMI), respectively. Results: A total of 804 patients with AS (241 TNFi users and 563 non-TNFi users) were recruited. For TNFi users, 83% received an etanercept biosimilar and 17.0% received adalimumab. Seventy-three TNFi users (30.3%) discontinued TNFis during the follow-up period; the mean duration of TNFi treatment was 6.9 ± 3.2 months. Reductions in ASDAS were significantly greater in TNFi users than in nonusers at 3, 6, and 12 months (differences in ASDAS reduction were 0.61, 0.56, and 0.46 units, respectively, all P < 0.05). Similarly, the improvement in BASFI was significantly greater in users than in nonusers at 3, 6, and 12 months (differences in BASFI improvement: 0.31, 0.75, and 0.74 units, respectively, all P < 0.05). BASMI increased in nonusers at 6 and 12 months (0.27, P = 0.47; 0.66, P < 0.001, respectively), but did not change in users (-0.16 and -0.13, respectively, both P > 0.05). At 12 months, changes in BASMI were significantly greater in nonusers than in users (-0.60, P = 0.47). Conclusion: TNFis are effective against disease activity and improve the physical functionality of patients with AS, even in those who taper or discontinue TNFis. Thus, TNFis may retard the progression of spinal mobility dysfunction in AS patients. TNF may maintain spinal mobility as indicated by the BASMI.