How Does Ultrasound Global OMERACT-EULAR Synovitis Score (GLOESS) for Rheumatoid Arthritis (RA) Activity Assessment Perform in Real-Life?

OBJECTIVE: This study aimed to assess the effectiveness of the Global OMERACT-EULAR Synovitis Score (GLOESS) of bilateral second to fifth metacarpophalangeal joints (MCP 2-5) in evaluating rheumatoid arthritis (RA) activity in a real-life setting. METHODS: This cross-sectional study included consecutive RA patients without hyperalgesia. Clinical data were extracted from electronic medical records. Evaluations were conducted on bilateral MCP 2-5 by two independent experts in musculoskeletal ultrasound (MSUS). Correlation between clinical and ultrasonographic parameters was analyzed, aiming to define a cutoff value for detecting disease activity. RESULTS: Sixty-nine patients were included. The mean DAS28-ESR was 4.3 (±1.4), and the median GLOESS was 7 (13). The correlation between GLOESS and DAS28 was moderate (r = .62; P < .05). A total GLOESS score of ≤3 and all joints with both GS and PD ≤1 showed good sensitivity and specificity for detecting disease activity (remission/low vs moderate/high, P = 0). CONCLUSION: In a real-life scenario, GLOESS for MCP 2-5 emerges as a valuable measure of RA activity. The optimal cutoff distinguishing remission/low from moderate/high disease activity was determined to be GLOESS ≤3, with all MCP joints exhibiting both GS and PD scores of ≤1.

Osteoid Osteoma of the Talus Mimicking Pigmented Villonodular Synovitis in a 15-Year-Old Male: A Case Report.

Osteoid osteoma is a benign tumor of the bone which tends to occur in diaphysis or metaphysis of the long bones. The lesion is generally intraosseous with vague clinical symptoms, hence given the name "great mimicker". When located subperiosteally and juxtaarticulary, atypical clinical presentation and radiological may lead to a delayed or missed diagnosis. Performing surgery with a misdiagnosis carries the risk of incomplete resection of the lesion and recurrence. We report the case of a 15-year-old male with a subperiosteal osteoid osteoma of the talus, who was misdiagnosed with pigmented villonodular synovitis and operated through anterior ankle arthrotomy. A nodular lesion 1 cm in diameter with hard rubber consistency was removed from the dorsal aspect of the talar neck. The pathological specimens were consistent with subperiosteal osteoid osteoma. The patient's symptoms resolved rapidly in the early postoperative period. The patient remained asymptomatic at the 20th-month follow-up and the control MRI revealed no signs of recurrence. Atypical radiological and clinical presentation of juxtaarticular subperiosteal osteoid osteomas cause misdiagnosis, delay in diagnosis, incomplete resection and recurrence. It is important to keep in mind "juxtaarticular subperiosteal osteoid osteoma" in the differential diagnosis of cases with suspected Pigmented Villonodular Synovitis.

Structural alterations and pain perception at the ankle joint in patients with haemophilia.

BACKGROUND: Patients with haemophilia (PwH) suffer from chronic pain due to joint alterations induced by recurring haemorrhage. OBJECTIVES: This study aimed to investigate the relationship between structural alterations and pain perception at the ankle joint in PwH. PATIENTS/METHODS: Ankle joints of 79 PwH and 57 healthy controls (Con) underwent ultrasound examination (US) and assessment of pain sensitivity via pressure pain thresholds (PPT). US discriminated between joint activity (synovitis) and joint damage (cartilage and/or bone degeneration) applying the HEAD-US protocol. Based on US-findings, five subgroups were built: PwH with activity/damage, PwH with activity/no damage, PwH with no activity/no damage, controls with activity/no damage and controls with no activity/no damage. RESULTS: Joint activity and joint damage were significantly increased in ankles of PwH compared to Con (p ≤.001). Subgroup analysis revealed that structural alterations negatively impact pain perception. This is particularly evident when comparing PwH with both activity/damage to PwH with no activity/no damage at the tibiotalar joint (p = .001). At the fibulotalar joint, no significant differences were observed between PwH subgroups. Further analysis showed that both joint activity and joint damage result in an increase in pain sensitivity (p ≤.001). CONCLUSION: The data suggest a relation between joint activity, joint damage and pain perception in PwH. Even minor changes due to synovitis appear to affect pain perception, with the effect not intensifying at higher levels of inflammation. In terms of joint damage, severe degeneration leads to a sensitised pain state most robustly, whereas initial changes do not seem to significantly affect pain perception.

Insights into the Roles of Natural Killer Cells in Osteoarthritis.

Osteoarthritis (OA) is now widely acknowledged as a low-grade inflammatory condition, in which the intrinsic immune system plays a significant role in its pathogenesis. While the involvement of macrophages and T cells in the development of OA has been extensively reviewed, recent research has provided mounting evidence supporting the crucial contribution of NK cells in both the initiation and advancement of OA. Accumulated evidence has emerged in recent years indicating that NK cells play a critical role in OA development and progression. This review will outline the ongoing understanding of the utility of NK cells in the etiology of OA, focusing on how NK cells interact with chondrocytes, synoviocytes, osteoclasts, and other immune cells to influence the course of OA disease.

Haemophilic arthropathy: Diagnosis, management, and aging patient considerations.

Gene therapy and universal use of safer, more effective, and personalised prophylactic regimens (factor, and nonfactor) are expected to prevent joint bleeding and promote joint health in persons with haemophilia (PwH). Growing evidence suggests that subclinical bleeding, with active and inactive synovial proliferation, continues and haemophilic arthropathy remains a major morbidity in PwH despite early institution of joint prophylaxis. Joint health assessment is evolving with physical examination scores complementing imaging scores. Point-of-care ultrasound is emerging as a safe, cost-effective, and readily available tool for acute determination of musculoskeletal abnormalities, serial evaluation of joints for sonographic markers of haemophilic arthropathy, and in providing objective insight into the efficacy of new therapies. In acute haemarthrosis, arthrocentesis expedites recovery and prevent the vicious cycle of bleed-synovitis-rebleed. When synovial proliferation develops, a multidisciplinary team approach is critical with haematology, orthopaedics, and physiotherapy involvement. Synovectomy is considered for patients with chronic synovitis that fail conservative management. Non-surgical and minimally invasive procedures should always be offered and considered first. Careful patient selection, screening and early intervention increase the success of these interventions in reducing bleeding, pain, and improving joint function and quality of life. Chemical synovectomy is practical in developing countries, but radioactive synovectomy appears to be more effective. When surgical synovectomy is considered, arthroscopic/minimally invasive approach should be attempted first. In advanced haemophilic arthropathy, joint replacement and arthrodesis can be considered. While excited about the future of haemophilia management, navigating musculoskeletal challenges in the aging haemophilia population is equally important.

The effect of low dose intra-articular S(+) ketamine on osteoarthritis in rats: an experimental study.

BACKGROUND: This study aimed to investigate the analgesic impact of S(+)-ketamine on pain behavior and synovial inflammation in an osteoarthritis (OA) model. METHODS: Animals were grouped as follows: OA-Saline (n = 24) and OA-Ketamine (n = 24), OA induced via intra-articular sodium monoiodoacetate (MIA); a Non-OA group (n = 24) served as the control. On the 7th day post OA induction, animals received either saline or S(+)-ketamine (0.5 mg.kg-1). Behavioral and histopathological assessments were conducted up to day 28. RESULTS: S(+)-ketamine reduced allodynia from day 7 to 28 and hyperalgesia from day 10 to 28. It notably alleviated weight distribution deficits from day 10 until the end of the study. Significant walking improvement was observed on day 14 in S(+)-ketamine-treated rats. Starting on day 14, OA groups showed grip force decline, which was countered by S(+)-ketamine on day 21. However, S(+)-ketamine did not diminish synovial inflammation. CONCLUSION: Low Intra-articular (IA) doses of S(+)-ketamine reduced MIA-induced OA pain but did not reverse synovial histopathological changes. IRB APPROVAL NUMBER: 23115 012030/2009-05.

Risk of developing psoriatic arthritis in psoriasis cohorts with arthralgia: exploring the subclinical psoriatic arthritis stage.

OBJECTIVE: Subjects with subclinical psoriatic arthritis (PsA), defined as the presence of arthralgia in psoriasis (PsO), are at higher risk of PsA but scant real-world data exist. Our aims were to (1) estimate the probability of PsA development in subclinical PsA, (2) characterise subclinical PsA symptoms and (3) determine the clinical patterns at PsA diagnosis. METHODS: Patients with PsO, mainly subclinical PsA, were evaluated longitudinally in two European cohorts. The key outcome was new-onset PsA. Musculoskeletal symptoms including inflammatory and non-inflammatory symptoms before PsA diagnosis were collected. Occurrence of PsA was analysed with survival analysis and cumulative incidence functions (CIFs). RESULTS: 384 patients with PsO were included with a mean follow-up of 33.0 (±20.9) months. 311 of 384 (80.9%) had subclinical PsA with a PsA incidence rate of 7.7 per 100 patient-years. Subclinical PsA displayed a higher risk of PsA development compared with PsO (HR=11.7 (95% CI 1.57 to 86.7), p=0.016). The probability of new-onset PsA estimated by the CIF was 9.4% (95% CI 4.7% to 10.6%) at month 12 and 22.7% (95% CI 17.2% to 28.6%) at month 36. 58.9% of cases reported inflammatory symptoms in the months immediately prior to PsA diagnosis but prior non-inflammatory symptoms were evident in 83.9% prior to PsA diagnosis. Peripheral joint swelling was the predominant PsA presentation pattern (82.1%). CONCLUSIONS: The probability of PsA development among subclinical PsA was relatively high, emphasising the importance of emergent musculoskeletal symptoms when aiming for PsA prevention. Joint swelling was the dominant feature in new-onset PsA, likely reflecting clinical confidence in recognising joint swelling.

Effect of weight loss on knee joint synovitis over 48 months and mediation by subcutaneous fat around the knee: data from the Osteoarthritis Initiative.

BACKGROUND: Obesity influences the development of osteoarthritis via low-grade inflammation. Progression of local inflammation (= synovitis) increased with weight gain in overweight and obese women compared to stable weight. Synovitis could be associated with subcutaneous fat (SCF) around the knee. Purpose of the study was to investigate the effect of weight loss on synovitis progression and to assess whether SCF around the knee mediates the relationship between weight loss and synovitis progression. METHODS: We included 234 overweight and obese participants (body mass index [BMI] ≥ 25 kg/m2) from the Osteoarthritis Initiative (OAI) with > 10% weight loss (n = 117) or stable overweight (< ± 3% change, n = 117) over 48 months matched for age and sex. In magnetic resonance imaging (MRI) at baseline and 48 months, effusion-synovitis and Hoffa-synovitis using the MRI Osteoarthritis Knee Score (MOAKS) and average joint-adjacent SCF (ajSCF) were assessed. Odds-ratios (ORs) for synovitis progression over 48 months (≥ 1 score increase) were calculated in logistic regression models adjusting for age, sex, baseline BMI, Physical Activity Scale for the Elderly (PASE), and baseline SCF measurements. Mediation of the effect of weight loss on synovitis progression by local SCF change was assessed. RESULTS: Odds for effusion-synovitis progression decreased with weight loss and ajSCF decrease (odds ratio [OR] = 0.61 and 0.56 per standard deviation [SD] change, 95% confidence interval [CI] 0.44, 0.83 and 0.40, 0.79, p = 0.002 and 0.001, respectively), whereas odds for Hoffa-synovitis progression increased with weight loss and ajSCF decrease (OR = 1.47 and 1.48, CI 1.05, 2.04 and 1.02, 2.13, p = 0.024 and 0.038, respectively). AjSCF decrease mediated 39% of the effect of weight loss on effusion-synovitis progression. CONCLUSIONS: Effusion-synovitis progression was slowed by weight loss and decrease in local subcutaneous fat. Hoffa-synovitis characterized by fluid in the infrapatellar fat pad increased at the same time, suggesting a decreasing fat pad rather than active synovitis. Decrease in local subcutaneous fat partially mediated the systemic effect of weight loss on synovitis.

Measuring synovial thickness on knee MRI in pediatric patients with arthritis: is contrast necessary?

BACKGROUND: The use of contrast-enhanced imaging has long been standard for magnetic resonance imaging (MRI) assessments of synovitis in juvenile idiopathic arthritis (JIA). However, advancements in MRI technology have allowed for reliable identification of synovium without contrast. OBJECTIVE: To assess the equivalence of unenhanced MRI with contrast-enhanced MRI in evaluating synovial thickness. MATERIALS AND METHODS: This is an institutional review board approved, retrospective study performed in a tertiary children's hospital. Pediatric JIA patients under 21 years old were included who underwent knee MRI scans (1.5 T or 3 T) without and with contrast between January 2012 and January 2022. Two radiologists independently measured synovial thickness at 6 knee sites on contrast-enhanced and unenhanced sequences. Numerical measurements and ordinal scores based on juvenile idiopathic arthritis magnetic resonance imaging scoring (JAMRIS) system were recorded, and tests of equivalence were conducted, as well as between-reader and within-reader reliability by concordance correlation coefficient (CCC). All tests were considered significant at the 5% level. RESULTS: A total of 38 studies from 35 patients (25 females, median age 14 years; interquartile range 7 to 15.7) were included. Equivalence was demonstrated at each of the 6 sites for both continuous measurements (P-values < 0.05) and ordinal scores (P-values < 0.05) based on the average over readers. Within-reader reliability was moderate to high (CCC 0.50-0.89), except for the cruciate ligaments site. Averaged over the 6 sites, reliability between readers was low for unenhanced (CCC 0.47, with 95% CI: [0.41, 0.53]) and moderate for contrast-enhanced (CCC 0.64, with 95% CI: [0.59, 0.69]) sequences. CONCLUSION: Unenhanced knee MRI is equivalent to contrast-enhanced MRI in assessment of synovial thickness using conventional MRI sequences. Contrast material helped improve inter-reader reliability.

More than skin-deep elbow pain in a psoriatic arthritis patient after phlebotomy.

Bicipitoradial bursitis is an unusual cause of cubital fossa pain in PsA patients. Bedside Ultrasound is a valuable tool to correlate the source of pain in rheumatic and musculoskeletal diseases.

Preoperative Synovial Tissue and Synovial Fluid Biomarkers as Predictors for Outcomes After Knee Arthroscopy and ACL Reconstruction: A Narrative Review.

Background: Biomarkers collected in synovial tissue and fluid have been identified as potential predictors of outcomes after arthroscopy. Purpose: To provide a narrative review of the current literature that assesses the associations between preoperative biomarkers in the synovial fluid or synovial tissue and patient outcomes after knee arthroscopy. Study Design: Narrative review. Methods: We searched the PubMed database with keywords, "biomarkers AND arthroscopy," "biomarkers AND anterior cruciate ligament reconstruction," and "biomarkers AND meniscectomy." To be included, studies must have collected synovial fluid or synovial tissue from patients before or during arthroscopic knee surgery and analyzed the relationship of biomarkers to postoperative patient outcomes. Biomarkers were classified into 4 main categories: metabolism of aggrecan in cartilage, metabolism of collagen in cartilage (type II collagen), noncollagenous proteins in the knee, and other. When biomarker levels and outcomes were expressed with continuous variables, we abstracted the Pearson or Spearman correlation coefficients as the effect measure. If the biomarker values were continuous and the outcomes binary, we abstracted the mean or median biomarker values in those with favorable versus unfavorable outcomes. We calculated effect sizes as the difference between means of both groups divided by the standard deviation from the mean in the group with better outcomes. Results: Eight studies were included in the review. Each study reported different patient outcomes. Biomarkers associated with metabolism of aggrecan, type II collagen metabolism, and noncollagenous proteins as well as inflammatory biomarkers had statistically significant associations with a range of patient outcomes after knee arthroscopy. Difference across studies in sample size and outcome measures precluded choosing a single biomarker that best predicted patient outcomes. Conclusion: The findings suggest that biomarkers associated with metabolism of aggrecan, type II collagen metabolism, noncollagenous proteins, as well as inflammatory biomarkers may help surgeons and their patients anticipate surgical outcomes.

The relationship of ALPK1, hyaluronic acid and M1 macrophage polarization in the temporomandibular joint synovitis.

M1 macrophage polarization and synovitis play an important role in the pathogenesis of temporomandibular joint osteoarthritis (TMJOA). Reduced molecular weight of hyaluronic acid (HA) in synovial fluid of patients with TMJOA. In addition, high molecular weight hyaluronic acid (HMW-HA) is often used clinically to treat TMJ inflammation. As a pattern recognition receptor of the cytoplasm, ALPK1 was found to be pro-inflammatory in a variety of diseases. However, the relationship of ALPK1, HA and M1 macrophage polarization in TMJ synovitis remains unclear. We aimed to investigate the role of ALPK1 and HA in macrophage polarization and TMJ synovitis and the underlying mechanisms. The results demonstrated that ALPK1 was highly upregulated in the synovial macrophages in the inflamed TMJ synovium of patients. Low molecular weight hyaluronic acid (LMW-HA) promoted the expression of ALPK1 and M1 macrophage-associated genes. Besides, rhALPK1 promoted the expression of M1 macrophage-associated factors and the nuclear translocation of PKM2. Furthermore, ALPK1 knockout mice exhibited limited infiltration of macrophages and decreased expression levels of M1 macrophage-associated genes in CFA-induced TMJ synovitis. While HMW-HA inhibited the expression of ALPK1 and M1 macrophage polarization. Our results elucidated that ALPK1 promoted TMJ synovitis by promoting nuclear PKM2-mediated M1 macrophage polarization, whereas HMW-HA inhibited the expression of ALPK1 as well as M1 macrophage polarization.

Reactive Arthritis as a Consequence of Infection by Clostridium difficile in a Pediatric Patient.

Reactive arthritis (RA) is the development of a sterile inflammatory arthritis usually associated with a previously known infection, most commonly from the gastrointestinal or urogenital tract. The diagnosis is clinical, based on the presence of acute oligoarticular arthritis of larger joints developing within two to four weeks of the infection. However, in some cases where the infection is not clear, the diagnosis is a challenge, like in the case presented here. We must always rule out past infections as a cause of arthritis by directly asking about the presence of symptomatology associated with it, presented in the past few weeks. It's important to emphasize that human leukocyte antigen B27 (HLA-B27) should not be used as a diagnostic tool, and it always needs to be correlated with the clinical features. There is no confirmed evidence in the literature that is in favor of prescribing antibiotic therapy during an acute presentation of RA as it usually presents after the infection is cured.

Invasion Patterns and Long-Term Clinical Outcomes of Diffuse Tenosynovial Giant Cell Tumor of the Ankle Joint.

BACKGROUND: The invasion patterns and long-term outcomes of diffuse tenosynovial giant cell tumor (D-TSGCT) of the ankle joint remain unclear. METHODS: Seven patients who visited our department between 2011 and 2023 and were diagnosed with D-TSGCT of the ankle joint by contrast-enhanced MRI and a pathological diagnosis were included. The invasion patterns of ankle D-TSGCT on MRI were investigated. The recurrence rate and clinical symptoms were examined in five patients followed up for more than seven years after total resection. RESULTS: In seven patients (1 male/6 females, mean age 37.0±16.6 years, range 15-57 years) with D-TSGCT of the ankle joint, contrast-enhanced MRI at the initial presentation showed invasion within the ankle joint, extending along the tendon sheath, within the talocalcaneal joint, and in the tarsal sinus in 100% of cases, around the deltoid ligament in 86%, within the plantar surface in 43%, invasion of the interosseous membrane in 57%, around the Achilles tendon in 29%, and scalloping on the talocrural joint in 43%. The mean time from mass awareness to the first visit was 51.9±80.0 months (range 1-240 months). Gross total resection, defined as the removal of all tumors as gauged by MRI, was initially performed on 6/7 patients. One patient underwent partial resection of only the anterior part of the tumor. Of the six cases in which gross total resection was performed, 5 had long-term follow-up of more than seven years post-operatively, and one case is still only one year post-operatively. The long-term results of five patients followed for more than seven years after total resection were as follows: a mean follow-up period of 125 months (range 89-171 months), a 100% recurrence rate, a mean time to recurrence of 27.5±19.2 months (range 7-60 months), and a 16% reoperation rate. In the last follow-up, osteoarthritic changes were observed radiographically in 2/5 patients (40%), both of whom had scalloping of the talocrural joint on MRI at the time of the initial diagnosis. Four of the five patients (80%) had no clinical symptoms in the last follow-up. CONCLUSION: Ankle D-TSGCT presents with a strong local infiltrative pattern inside and outside the ankle joint along the tendon sheath, radical resection may be difficult, and the recurrence rate may be higher than previously reported. On the other hand, there are many cases that remain free of clinical symptoms in the long term after recurrence, and surgical indications for ankle D-TSGCT need to consider function preservation as well as recurrence rates.

Is Active Synovitis of Metacarpophalangeal Joints a Neuropathic Condition in Rheumatoid Arthritis Patients? Results from an Ultrasound Study of Palmar Digital Nerves.

(1) Background: Rheumatoid arthritis (RA) is a chronic inflammatory joint disease, primarily characterized by pain. A significant proportion of patients report symptoms suggestive of neuropathic pain. The objectives of this study were to investigate the presence of an increased cross-sectional area (CSA) of the palmar digital nerves by ultrasound in patients with active synovitis of the metacarpophalangeal joints and to identify potential predictors of such an increase. (2) Methods: An ultrasound examination of the clinically most affected hand (from the second to the fifth metacarpophalangeal joint) was performed. The presence of synovitis was scored using a 0-3 semiquantitative method for each joint. The CSA of each pair of palmar digital nerves was measured. (3) Results: A significant correlation was found between the sum of the CSAs of the nerves and the Clinical Disease Activity Index (CDAI) (r = 0.387), as well as with the ultrasonographic grading of synovitis (r = 0.381) both at the patient and the joint level. These two variables, aimed at measuring disease activity, along with male gender, are the only predictors of the CSA of the palmar digital nerves. (4) Conclusions: Synovial inflammation of the metacarpophalangeal joints is, therefore, a condition that can influence the CSA of the palmar digital nerves and may partially explain neuropathic pain in patients with RA.

Effects of intra-articular injection of platelet-rich plasma on the inflammatory process and histopathological characteristics of cartilage and synovium in animals with osteoarthritis: a systematic review with meta-analysis.

BACKGROUND: Osteoarthritis (OA) affects the entire joint, causing structural changes in articular cartilage, subchondral bone, ligaments, capsule, synovial membrane, and periarticular muscles that afflicts millions of people globally, leading to persistent pain and diminished quality of life. The intra-articular use of platelet-rich plasma (PRP) is gaining recognition as a secure therapeutic approach due to its potential regenerative capabilities. However, there is controversial clinical data regarding efficacy of PRP for OA treatment. In this context, gathering scientific evidence on the effects of PRP in treating OA in animal models could provide valuable insights into understanding its impact on aspects like cartilage health, synovial tissue integrity, and the inflammatory process in affected joints. Thus, the objective of this study was to assess the effects of PRP injections on inflammation and histopathological aspects of cartilage and synovium in animal models of OA through a comprehensive systematic review with meta-analysis. METHODS: A electronic search was conducted on Medline, Embase, Web of Science, The Cochrane Library, LILACS, and SciELO databases for relevant articles published until June 2022. A random-effects meta-analysis was employed to synthesize evidence on the histological characteristics of cartilage and synovium, as well as the inflammatory process. The GRADE approach was utilized to categorize the quality of evidence, and methodological quality was assessed using SYRCLE's RoB tool. RESULTS: Twenty-one studies were included in the review, with twelve of them incorporated into the meta-analysis. PRP treatment demonstrated superior outcomes compared to the control group in terms of cartilage histology (very low quality; p = 0.0002), synovium histology (very low quality; p < 0.0001), and reductions in proinflammatory markers, including IL-1 (low quality; p = 0.002), IL-6 (very low quality; p < 0.00001), and TNF-α (very low; p < 0.00001). However, PRP treatment did not yield a significant impact on PDGF-A levels (very low quality; p = 0.81). CONCLUSION: PRP appears capable of reducing proinflammatory markers (IL-1, IL-6, TNF-α) and mitigating cartilage and synovium damage in animals with OA. However, the levels of evidence of these findings are low to very low. Therefore, more rigorous studies with larger samples are needed to improve the quality of evidence. PROSPERO REGISTRATION: CRD42022250314.

Validation and incorporation of digital entheses into a preliminary GLobal OMERACT Ultrasound DActylitis Score (GLOUDAS) in psoriatic arthritis.

OBJECTIVES: The main objective was to generate a GLobal OMERACT Ultrasound DActylitis Score (GLOUDAS) in psoriatic arthritis and to test its reliability. To this end, we assessed the validity, feasibility and applicability of ultrasound assessment of finger entheses to incorporate them into the scoring system. METHODS: The study consisted of a stepwise process. First, in cadaveric specimens, we identified enthesis sites of the fingers by ultrasound and gross anatomy, and then verified presence of entheseal tissue in histological samples. We then selected the entheses to be incorporated into a dactylitis scoring system through a Delphi consensus process among international experts. Next, we established and defined the ultrasound components of dactylitis and their scoring systems using Delphi methodology. Finally, we tested the interobserver and intraobserver reliability of the consensus- based scoring systemin patients with psoriatic dactylitis. RESULTS: 32 entheses were identified in cadaveric fingers. The presence of entheseal tissues was confirmed in all cadaveric samples. Of these, following the consensus process, 12 entheses were selected for inclusion in GLOUDAS. Ultrasound components of GLOUDAS agreed on through the Delphi process were synovitis, tenosynovitis, enthesitis, subcutaneous tissue inflammation and periextensor tendon inflammation. The scoring system for each component was also agreed on. Interobserver reliability was fair to good (κ 0.39-0.71) and intraobserver reliability good to excellent (κ 0.80-0.88) for dactylitis components. Interobserver and intraobserver agreement for the total B-mode and Doppler mode scores (sum of the scores of the individual abnormalities) were excellent (interobserver intraclass correlation coefficient (ICC) 0.98 for B-mode and 0.99 for Doppler mode; intraobserver ICC 0.98 for both modes). CONCLUSIONS: We have produced a consensus-driven ultrasound dactylitis scoring system that has shown acceptable interobserver reliability and excellent intraobserver reliability. Through anatomical knowledge, small entheses of the fingers were identified and histologically validated.

Peptidoglycan in osteoarthritis synovial tissue is associated with joint inflammation.

OBJECTIVES: Peptidoglycan (PG) is an arthritogenic bacterial cell wall component whose role in human osteoarthritis is poorly understood. The purpose of this study was to determine if PG is present in synovial tissue of osteoarthritis patients at the time of primary total knee arthroplasty (TKA), and if its presence is associated with inflammation and patient reported outcomes. METHODS: Intraoperative synovial tissue and synovial fluid samples were obtained from 56 patients undergoing primary TKA, none of whom had history of infection. PG in synovial tissue was detected by immunohistochemistry (IHC) and immunofluorescence microscopy (IFM). Synovial tissue inflammation and fibrosis were assessed by histopathology and synovial fluid cytokine quantification. Primary human fibroblasts isolated from arthritis synovial tissue were stimulated with PG to determine inflammatory cytokine response. RESULTS: A total of 33/56 (59%) of primary TKA synovial tissue samples were positive for PG by IHC, and PG staining colocalized with markers of synovial macrophages and fibroblasts by IFM. Synovial tissue inflammation and elevated IL-6 in synovial fluid positively correlated with PG positivity. Primary human fibroblasts stimulated with PG secreted high levels of IL-6, consistent with ex vivo findings. Interestingly, we observed a significant inverse correlation between PG and age at time of TKA, indicating younger age at time of TKA was associated with higher PG levels. CONCLUSION: Peptidoglycan is commonly found in synovial tissue from patients undergoing TKA. Our data indicate that PG may play an important role in inflammatory synovitis, particularly in patients who undergo TKA at a relatively younger age.

Subclinical synovitis impact on the progression of lupus joint disease: A 10-year longitudinal multicenter study.

OBJECTIVE: To determine the effect of subclinical synovitis on the progression of joint disease in a cohort of patients with systemic lupus erythematosus over a mean follow-up of 10 years. METHODS: A longitudinal follow-up of 96 patients diagnosed with lupus was performed. All patients were considered clinically free of joint disease or with minimal joint impairment at baseline and were studied through ultrasound study of their dominant hand to assess the prevalence of subclinical synovitis. Now, over 10 years after we contacted them and reviewed their evolution to determine the impact of had or had not been diagnosed with subclinical synovitis in their current joint condition. RESULTS: Thirty-one of the 91 reached patients developed clinical progression in their joint manifestations (at least one ordinal degree of worsening). Of these, 23 (74,9%) had demonstrated subclinical synovitis at baseline. In the group of patients who did not progress clinically, 46 (76,6%) did not have this finding at the start of follow-up (p < .01, OR 9,44 95%CI 3,46-25,74). The patients in whom clinical progression was demonstrated had worse combined ultrasound scores than the rest of the patients: 6,41 SD 1,45 vs. 1,15 SD 0,97 (p < .01). CONCLUSIONS: The finding of subclinical synovitis in patients with systemic lupus erythematosus is associated with the development of joint disease progression both clinically and ultrasonographically.

A simple, clinically usable whole-body MRI system of joint assessment in adolescents and young people with juvenile idiopathic arthritis.

OBJECTIVES: To introduce and evaluate a simple method for assessing joint inflammation and structural damage on whole-body MRI (WBMRI) in juvenile idiopathic arthritis (JIA), which is usable in clinical practice. METHODS: The proposed system utilises post-contrast Dixon WBMRI scans. Joints are assessed for synovitis (grade 0-2) and structural damage (present/absent) at 81 sites. The synovitis grading is based on features including above-normal intensity synovial enhancement, synovial hypertrophy, joint effusion, subarticular bone marrow oedema and peri-articular soft tissue oedema.This system was evaluated in a prospective study of 60 young people (47 patients with JIA and 13 controls with non-inflammatory musculoskeletal pain) who underwent a WBMRI. Three readers (blinded to diagnosis) independently reviewed all images and re-reviewed 20 individual scans. The intra- and inter-reader overall agreement (OA) and the intra- and inter-reader Gwet's agreement coefficients 2 (GAC2) were measured for the detection of a) participants with ≥1 joint with inflammation or structural damage and b) joint inflammation or structural damage for each joint. RESULTS: The inter-reader OA for detecting patients with ≥1 joint with inflammation, defined as grade 2 synovitis (G2), and ≥1 joint with structural damage were 80% and 73%, respectively. The intra-reader OA for readers 1-3 were 80-90% and 75-90% respectively. The inter-reader OA and GAC2 for joint inflammation (G2) at each joint were both ≥85% for all joints but were lower if grade 1 synovitis was included as positive. CONCLUSION: The intra- and inter-reader agreements of this WBMRI assessment system are adequate for assessing objective joint inflammation and damage in JIA.