Synovial Abnormalities Research Articles

Associations between hyperuricemia and ultrasound-detected knee synovial abnormalities in middle-aged and older population: a cross-sectional study

ObjectivesKnee synovial abnormalities, potentially treatment targets for knee pain and osteoarthritis, are common in middle-aged and older population, but its etiology remains unclear. We examined the associations between hyperuricemia and knee synovial abnormalities detected by ultrasound in a general population sample.MethodsParticipants aged ≥ 50 years were from a community-based observational study. Hyperuricemia was defined as serum urate (SU) level > 416 µmol/L in men and > 357 µmol/L in women. Ultrasound of both knees was performed to determine the presence of synovial abnormalities, i.e., synovial hypertrophy, effusion, or Power Doppler signal (PDS). We examined the relation of hyperuricemia to prevalence of knee synovial abnormalities and its laterality, and the dose-response relationships between SU levels and the prevalence of knee synovial abnormalities.ResultsIn total, 3,405 participants were included in the analysis. Hyperuricemia was associated with higher prevalence of knee synovial abnormality (adjusted odds ratio [aOR] = 1.21, 95% confidence interval [CI]: 1.02 to 1.43), synovial hypertrophy (aOR = 1.33, 95% CI: 1.05 to 1.68), and effusion (aOR = 1.21, 95% CI: 1.02 to 1.44), respectively. There were dose-response relationships between SU levels and synovial abnormalities. Additionally, the hyperuricemia was more associated with prevalence of bilateral than with that of unilateral knee synovial abnormality, synovial hypertrophy, or effusion; however, no significant association was observed between hyperuricemia and PDS.ConclusionIn this population-based study we found that hyperuricemia was associated with higher prevalence of knee synovial abnormality, synovial hypertrophy and effusion, suggesting that hyperuricemia may play a role in pathogenesis of knee synovial abnormalities.

Correction: Prevalence and distribution of ultrasound-detected hand synovial abnormalities in a middle-aged and older population.

Correction: Prevalence and distribution of ultrasound-detected hand synovial abnormalities in a middle-aged and older population.

Diagnostic Accuracy of Ultrasound for Assessment of Synovial Abnormalities Among Patients With Knee Pain: A Meta-Analysis.

Synovial abnormalities, which are modifiable treatment targets for knee pain, affect ~25% of adults. Ultrasound is a safe, inexpensive, and easily accessible imaging modality for assessing synovial abnormalities, but its diagnostic accuracy is still controversial. We conducted a meta-analysis by comparing ultrasound with the "reference standard" method, ie, magnetic resonance imaging (MRI), in assessing synovial abnormalities among patients with knee pain. PubMed, Embase, and Web of Science were searched from inception to January 7, 2022, to retrieve studies including patients with knee pain for evaluating 1) the diagnostic accuracy of ultrasound versus MRI for synovial abnormalities (synovitis and synovial effusion) and 2) the correlations of synovial abnormalities assessed by ultrasound and MRI. The summary of diagnostic accuracy was analyzed using the bivariate model, and the correlation coefficients were pooled using the random effects model. Fourteen studies were included, representing a total of 755 patients. The pooled sensitivity, specificity, and area under the curve were 0.88 (95% confidence interval [95% CI] 0.65-0.96), 0.70 (95% CI 0.51-0.84), and 0.81 (95% CI 0.77-0.84) for synovitis and 0.90 (95% CI 0.81-0.95), 0.86 (95% CI 0.77-0.92), and 0.94 (95% CI 0.91-0.96) for synovial effusion, respectively. Strong correlations between ultrasound- and MRI-diagnosed synovitis (r=0.64, 95% CI 0.56-0.71) and synovial effusion (r=0.63, 95% CI 0.52-0.73) were observed. Ultrasound demonstrated a promising accuracy in detecting synovial abnormalities among patients with knee pain. The use of ultrasound provides equivalent synovial information to MRI but is less expensive and more accessible. Therefore, it is recommended as an adjuvant for managing patients with knee pain during diagnostic strategy and individualized treatment decision-making.

Prevalence and distribution of ultrasound-detected hand synovial abnormalities in a middle-aged and older population.

Synovial abnormalities are modifiable targets for hand pain and osteoarthritis. We examined the prevalence and distribution of ultrasound-detected hand synovial abnormalities in a community-derived sample of older people in China. Within the Xiangya Osteoarthritis Study, a community-based study, we assessed synovial hypertrophy (SH), joint effusion, and Power Doppler signal (PDS) on all fingers and thumbs of both hands using standardized ultrasound examinations (score: 0-3). We assessed distribution patterns of SH and effusion using χ2-test and interrelationships of SH and effusion in different joints and hands by generalized estimating equations. Among 3,623 participants (mean age: 64.4 years; women: 58.1%), prevalence of SH, effusion and PDS were 85.5%, 87.3% and 1.5%, respectively. Prevalence of SH, effusion and PDS increased with age, was higher in the right hand than in the left hand and was more common in proximal than in distal hand joints. SH and effusion often occurred in multiple joints (P < 0.001). SH in one joint was strongly associated with presence of SH in the same joint of the opposite hand (odds ratio [OR]= 6.60, 95% confidence interval [CI]: 6.19-7.03) followed by SH in other joints in the same row, (OR=5.70, 95%CI: 5.32-6.11), and then other joints in the same ray of the same hand (OR=1.49, 95%CI: 1.39-1.60). Similar patterns were observed for effusion. Hand synovial abnormalities are common among older people, often affect multiple hand joints and present a unique pattern. These findings suggest both systemic and mechanical factors play roles in their occurrence.

Alterations to the synovial invaginations of the navicular bone are associated with pathology of both the navicular apparatus and distal interphalangeal joint when evaluated using high field MRI.

Limited information exists regarding associations between distal interphalangeal joint (DIPJ) abnormalities and synovial invagination changes in the distal sesamoid (navicular) bone. This retrospective, analytical study aimed to measure specific characteristics of the synovial invaginations of the navicular bone to determine whether any single characteristic was associated with abnormalities in the DIPJ or navicular apparatus (NA) using high field MRI and a sample of 200 horses' feet. The DIPJ and NA were graded independently by three scorers. The grades were averaged, creating a global pathology score for the DIPJ, NA, and synovial invaginations. Higher global scores represented more severe pathology. The number of invaginations, depth of penetration, invagination shape, and cross-sectional area (CSA) of the largest invagination were recorded. Interobserver agreement was measured using Cohen's Kappa. Associations of global scores of the DIPJ and NA with individual invagination characteristics were assessed using linear mixed modeling. A significant relationship was found between the number of invaginations and global DIPJ score, with higher invagination numbers associated with higher DIPJ scores. For invagination depth and CSA, a significant relationship was noted with global scores of both the DIPJ and NA. Reliable relationships between the shape of synovial invaginations and global scores of DIPJ and NA were not found, likely due to poor interobserver scoring (0.305). These findings suggest that primary DIPJ disease and NA pathology should be considered when noticing alterations to navicular synovial invaginations on MRI. This contrasts traditional views that synovial invagination abnormalities are indicative solely of NA pathology.

Which part of the blood in the knee joint is responsible for its detrimental effects? (An experimental study on the knee joint in rabbits).

This study aims to determine the potential causative elements which are responsible for the cartilage damage in case of frequent intra-articular bleeding and to evaluate the effects of intra-articular free iron and chelation of iron in the knee joint. Thirty-five New Zealand rabbits were randomly divided into five groups according to substances injected into their knee joints. Plasma (group I) and cellular components (group II) of the blood harvested from the rabbits, iron (ferric hydroxide sucrose) (group III), iron&chelator (group IV) and only chelator (deferoxamine mesylate) (group V) were injected into their right knees three times a week for 12 weeks. The joint surface was examined histologically according to the classification system modified from Colombo etal. The changes in the synovial tissue were evaluated according to the scoring system modified from Madhok etal. Cartilage and synovial abnormality scores were significantly higher in all study groups when compared to their own controls (p < 0.0001). Cartilage scores of groups I and V were significantly lower when compared to groups III and IV (p = 0.002 for group I and p = 0.003 for group V). Synovial abnormality score of group I was significantly lower than scores of groups III and IV (p = 0.001); and of group V lower than groups III and IV (p = 0.003 and p = 0.001, respectively). All substances tested in this study caused a certain amount of damage in the cartilage tissue and led to synovial abnormalities. Both iron and iron&chelator caused more damage in the cartilage and led to more advanced synovial changes when compared to the plasma component of blood and chelator itself. Influence of iron and iron&chelators were found to be similar showing that chelation was inadequate in antagonizing the detrimental effects of iron.

Network Pharmacology Analysis and Experimental Validation to Investigate the Mechanism of Total Flavonoids of Rhizoma Drynariae in Treating Rheumatoid Arthritis.

ObjectiveThe study aimed to explore the mechanism of total flavonoids of Rhizoma Drynariae (TFRD) in the treatment of rheumatoid arthritis (RA) based on network pharmacology and experimental validation.MethodsThe active components of TFRD were identified from TCMSP and TCMID databases. Relevant targets of the active compounds of TFRD and RA-related targets were predicted by public databases online. A component-target (C-T) regulatory network was constructed by Cytoscape. The genes of TFRD regulating RA were imported into STRING database to construct a protein-protein interaction (PPI) network in order to predict the key targets. KEGG enrichment analysis was performed to predict the crucial mechanism of TFRD against RA. The active components of TFRD underwent molecular docking with the key proteins. Collagen-induced arthritis (CIA) model of rats and inflammatory factors-stimulated fibroblast-like synoviocytes were used in vivo and in vitro to validate the efficacy and predicted critical mechanisms of TFRD.ResultsNetwork Pharmacology analysis revealed that TFRD had 14 active compounds, corresponding to 213 targets, and RA related to 2814 genes. There were 137 intersection genes between TFRD and RA. KEGG indicated that therapeutic effects of TFRD on RA involves T cell receptor signaling pathway, Th17 cell differentiation, IL-17 signaling pathway, TNF signaling pathway, MAPK signaling pathway and PI3K/AKT signaling pathway. In vivo experiments suggested TFRD can alleviate the inflammatory response, joint swelling and synovial abnormality of CIA rats. TFRD contributed to the decrease of Th17 cells and the down-regulated secretion of IL-17A and TNF-α of activated lymphocyte in CIA model. In vitro experiments confirmed TFRD can effectively inhibit the inflammatory response of fibroblast-like synoviocytes and suppress the abnormal activation of MAPK, PI3K/AKT and NFκB signaling pathways.ConclusionThe treatment of RA with TFRD is closely related to inhibiting Th17 differentiation and inflammatory response of synoviocytes.

ASSOCIATION BETWEEN HYPERURICEMIA AND ULTRASOUND-DETECTED KNEE SYNOVIAL ABNORMALITY: DATA FROM THE XIANGYA OSTEOARTHRITIS (XO) STUDY

Purpose: Knee synovial abnormality, a potentially modifiable treatment target for knee pain and osteoarthritis, is commonly detected in the older population, but the etiology remains unclear. We examined the associations between hyperuricemia and synovial abnormalities detected by ultrasound in a general population sample.

DYSBIOSIS OF GUT MICROBIOTA, POTENTIAL MEDIATOR OF BILE ACID COMPOSITIONS, AND PREVALENCE OF HAND SYNOVIAL ABNORMALITY: DATA FROM THE XIANGYA OSTEOARTHRITIS (XO) STUDY

Purpose: Hand synovial abnormality, a potentially modifiable pathological lesion, is associated with pain in hand osteoarthritis. Gut microbiota dysbiosis and the related bile acids changes could promote systemic inflammation that has been implicated in hand synovial abnormality. We examined the relation of gut microbiota to prevalent hand synovial abnormality and potential mediators of bile acids.

How Well Does MRI Predict Chondral Lesions in Patients with Femoroacetabular Impingement? An Analysis of 545 Cases (137)

Objectives:Articular cartilage injury has been identified as a risk factor for poor outcomes following hip arthroscopy for femoroacetabular impingement syndrome (FAI). The purpose of this study was to evaluate the efficacy of magnetic resonance imaging (MRI) in detecting cartilage defects, and to identify specific MRI findings associated with cartilage injury.Methods:All patients undergoing hip arthroscopy between February 2015 and May 2017 at one institution were enrolled in a prospective cohort. Intra-articular findings were documented at the time of surgery. MRI reports were retrospectively reviewed for radiologist-reported articular cartilage, osseous or synovial abnormalities. Sensitivity and specificity of MRI findings were calculated; multivariate logistic regression analysis determined which findings were associated with high-grade chondral damage at time of arthroscopy and used to create an online risk calculator, https://orthop.washington.edu/hiprisk/.Results:Out of a total of 598 patients who underwent hip arthroscopy, 550 had MRI reports available for review (92%). Grade III and IV cartilage injuries were reported on arthroscopy in 70 patients (13%) of average age 33 ± 13 years. On univariate analyses, individual MRI findings were not found to be sensitive in detection of articular cartilage injury (mean 22%, range 1.4% – 46%), but positive findings were highly specific (mean 90%, range 76% – 99%). Multivariate analysis revealed that older age (OR 1.09 [1.06-1.11], p < .001) and osseous findings such as subchondral cyst or edema (OR 4.77 [2.51-9.05], p <.001) were most predictive of grade III and IV defects (p < .001). An example of use of the online calculator is in Figure 1.Conclusions:MRI was a specific but not sensitive tool in diagnosing articular cartilage injury. Surgeons should be aware that osseous findings such as cysts or edema are highly predictive of full-thickness cartilage loss in FAI.

Single-cell sequencing of immune cells from anticitrullinated peptide antibody positive and negative rheumatoid arthritis

The presence or absence of anti-citrullinated peptide antibodies (ACPA) and associated disparities in patients with rheumatoid arthritis (RA) implies disease heterogeneity with unknown diverse immunopathological mechanisms. Here we profile CD45+ hematopoietic cells from peripheral blood or synovial tissues from both ACPA+ and ACPA- RA patients by single-cell RNA sequencing and identify subsets of immune cells that contribute to the pathogenesis of RA subtypes. We find several synovial immune cell abnormalities, including up-regulation of CCL13, CCL18 and MMP3 in myeloid cell subsets of ACPA- RA compared with ACPA+ RA. Also evident is a lack of HLA-DRB5 expression and lower expression of cytotoxic and exhaustion related genes in the synovial tissues of patients with ACPA- RA. Furthermore, the HLA-DR15 haplotype (DRB1/DRB5) conveys an increased risk of developing active disease in ACPA+ RA in a large cohort of patients with treatment-naive RA. Immunohistochemical staining shows increased infiltration of CCL13 and CCL18-expressing immune cells in synovial tissues of ACPA- RA. Collectively, our data provide evidence of the differential involvement of cellular and molecular pathways involved in the pathogenesis of seropositive and seronegative RA subtypes and reveal the importance of precision therapy based on ACPA status.

The interactions between MRI-detected osteophytes and bone marrow lesions or effusion-synovitis on knee symptom progression: an exploratory study

To investigate the longitudinal association between MRI-detected osteophyte scores and progression of knee symptoms, and whether the association was modified in the presence of bone marrow lesions (BMLs) or effusion-synovitis. Data from Vitamin D Effects on Osteoarthritis (VIDEO) study, a randomized, double-blinded and placebo-controlled clinical trial in symptomatic knee osteoarthritis (OA) patients, were analyzed as an exploratory study. Western Ontario and McMaster Universities Osteoarthritis Index (WOMAC) was used to assess knee symptoms. Osteophytes, BMLs and effusion-synovitis were measured using MRI. 334 participants with MRI information and WOMAC score (baseline and follow-up) were included in the analyses, with 24.3% of them having knee pain increased 2 years later. Statistically significant interactions were found between MRI-detected osteophytes and BMLs or effusion-synovitis on increased knee symptoms. In participants with BMLs, higher baseline scores of MRI-detected osteophytes in most compartments were significantly associated with increased total knee pain, weight-bearing pain, stiffness, and physical dysfunction, after adjustment for age, sex, body mass index, intervention and effusion-synovitis. In participants with effusion-synovitis, higher baseline scores of MRI-detected osteophytes in almost all the compartments were significantly associated with increased total knee pain, weight-bearing pain, stiffness, and physical dysfunction, after adjustment for age, sex, body mass index, intervention and BMLs. In contrast, MRI-detected osteophyte scores were generally not associated with knee symptom progression in participants without baseline BMLs or effusion-synovitis. MRI-detected OPs are associated with increased total knee pain, weight-bearing knee pain, stiffness and physical dysfunction in participants presenting BMLs or effusion-synovitis, but not in participants lacking BMLs or effusion-synovitis. This suggests they could interact with bone or synovial abnormalities to induce symptoms in knee OA.

Prevalence of ultrasound-detected knee synovial abnormalities in a middle-aged and older general population\u2014the Xiangya Osteoarthritis Study

BackgroundThere is paucity of data on the prevalence of ultrasound-detected synovial abnormalities in the general population, and the relationship between synovial changes and knee pain remains unclear. We examined the prevalence of synovial abnormalities on ultrasound and the relationship of these features with knee pain and radiographic osteoarthritis (ROA) in a community sample.MethodsParticipants aged 50 years or over were from the Xiangya Osteoarthritis Study, a community-based cohort study. Participants were questioned about chronic knee pain and underwent (1) ultrasonography of both knees to determine presence of synovial hypertrophy (≥ 4 mm), effusion (≥ 4 mm), and Power Doppler signal [PDS; yes/no]; and (2) standard radiographs of both knees (tibiofemoral and patellofemoral views) to determine ROA.ResultsThere were 3755 participants (mean age 64.4 years; women 57.4%). The prevalence of synovial hypertrophy, effusion, and PDS were 18.1% (men 20.2%; women 16.5%), 46.6% (men 49.9%; women 44.2%), and 4.9% (men 4.9%; women 5.0%), respectively, and increased with age (P for trend < 0.05). Synovial abnormalities were associated with knee pain, with adjusted odds ratios (aORs) of 2.39 (95% confidence interval [CI] 2.00–2.86) for synovial hypertrophy, 1.58 (95%CI 1.39–1.80) for effusion, and 4.36 (95%CI 3.09–6.17) for PDS. Similar associations with ROA were observed, the corresponding aORs being 4.03 (95%CI 3.38–4.82), 2.01 (95%CI 1.76–2.29), and 6.49 (95%CI 4.51–9.35), respectively. The associations between synovial hypertrophy and effusion with knee pain were more pronounced among knees with ROA than those without ROA, and the corresponding P for interaction were 0.004 and 0.067, respectively.ConclusionsKnee synovial hypertrophy and effusion are more common and increase with age, affecting men more than women. All three ultrasound-detected synovial abnormalities associate both with knee pain and ROA, and knee synovial hypertrophy or effusion and ROA may interact to increase the risk of knee pain.

Magnetic Resonance Imaging Predictors of Chondral Lesions in Patients With Femoroacetabular Impingement: An Analysis of 545 Cases

A large prospective cohort was used (1) to evaluate the overall ability of magnetic resonance imaging (MRI) to detect Outerbridge grade III and IV cartilage defects found during surgery and (2) to identify the specific MRI findings most associated with these cartilage defects so that the practicing hip arthroscopist can better predict cartilage injury before surgery. All patients undergoing hip arthroscopy between February 2015 and May 2017 at 1 institution were enrolled in a prospective cohort. Intra-articular findings were documented at the time of surgery. MRI reports were retrospectively reviewed for radiologist-reported articular cartilage, osseous, or synovial abnormalities. Sensitivity and specificity of MRI findings were calculated; multivariate logistic regression analysis determined which findings were associated with high-grade chondral damage at the time of arthroscopy and used to create an online risk calculator, https://orthop.washington.edu/hiprisk/. Of 598 patients who underwent hip arthroscopy, 550 had MRI reports available for review (92%). Grade III and IV cartilage injuries were reported on arthroscopy in 70 patients (13%) of average age 33 ± 13 years. On univariate analyses, individual MRI findings were not sensitive in detection of articular cartilage injury (mean 22%; range, 1.4%-46%), but positive findings were highly specific (mean 90%,; range, 76%-99%). Multivariate analysis revealed that older age (odds ratio [OR] 1.09 [1.06-1.11], P < .001) and osseous findings such as subchondral cyst or edema (OR 4.77 [2.51-9.05], P < .001) were most predictive of grade III and IV defects (P < .001). MRI was a specific but not sensitive tool in diagnosing articular cartilage injury. Surgeons should be aware that osseous findings such as cysts or edema are highly predictive of full-thickness cartilage loss in FAI. Level III, development of diagnostic criteria (consecutive patients with consistently applied reference standard, no blinding).

Association between ultrasound-detected synovial abnormalities and knee pain: data from the xiangya osteoarthritis (XO) study

Purpose: Pain is the predominant symptom of knee osteoarthritis (OA) and the main reason for disability. The association between local synovial changes and knee pain remained inconclusive. The aim of this study was to examine the relationship between knee synovial abnormalities detected by ultrasonography (US) and presence of knee pain in a population-based study.

Predominant ultrasonographic extracapsular changes in symptomatic psoriatic dactylitis: results from a multicenter cross-sectional study comparing symptomatic and asymptomatic hand dactylitis.

Despite diffuse digital swelling, dactylitis may sometimes be asymptomatic. The objective of this study was to compare the clinical and ultrasonographic features of symptomatic with asymptomatic psoriatic arthritis (PsA) dactylitis. One hundred and twenty-five hand dactylitis were evaluated in a multicenter cross-sectional study for the presence of pain, subjective functional limitation, and tenderness (4-points scale) with the calculation of a Leeds Dactylitis Index (LDI) score. Fingers were subsequently investigated using high-frequency ultrasound (US) both in gray-scale (GS) and power Doppler (PD), for the presence and grading of flexor tenosynovitis, soft tissue edema, subcutaneous PD signal (PDUS), extensor tendon involvement, and joints synovitis. Clinical and US characteristics of symptomatic dactylitic fingers were compared with the asymptomatic dactylitic ones. Symptomatic fingers (n = 80) had a significantly lower dactylitis duration compared to asymptomatic fingers (n = 36) (p < 0.001). Values of LDI, patient VAS-pain, and VAS-functional score were significantly higher in fingers with symptomatic dactylitis (p < 0.001 and p = 0.010, respectively). Symptomatic dactylitis had a higher prevalence of flexor tenosynovitis of grade >2, soft tissue edema and subcutaneous PDUS signal (p < 0.001). Asymptomatic dactylitis showed a greater prevalence of joint synovitis (both in GS and in PD) than symptomatic dactylitis (p < 0.001). Digital tenderness and pain are linked to US tenosynovitis of grade >2 and extra synovial abnormalities and conversely asymptomatic dactylitis is associated with joint-based synovitis.Key Points• Digital tenderness and local pain in psoriatic arthritis dactylitis are strongly associated with flexor tenosynovitis of grade>2, soft tissue edema, and subcutaneous PD signal.• In psoriatic arthritis, asymptomatic dactylitis showed a greater prevalence of joint synovitis than symptomatic dactylitis.• In psoriatic arthritis, ultrasound inflammatory abnormalities are present in about 70% of cold dactylitis which is linked for disease chronicity.• In psoriatic arthritis, the flexor tendon and adjacent soft tissues play a significant role in symptomatic dactylitis.

Ultrasound thresholds for synovial abnormalities.

Ultrasound thresholds for synovial abnormalities.

Thresholds of ultrasound synovial abnormalities for knee osteoarthritis – a cross sectional study in the general population

SummaryObjectiveTo establish “normal” ranges for synovial thickness and effusion detected by ultrasound (US) and to determine cut-offs associated with knee pain (KP) and radiographic knee osteoarthritis (RKOA) in the community.Methods147 women and 152 men ≥40 years old were randomly selected from the Nottingham KP and Related Health in the Community (KPIC) cohort (n = 9506). The “normal” range was established using the percentile method in 163 participants who had no KP and no RKOA. Optimal (maximum sensitivity and specificity) and high specificity (90%) cut-offs were established using receiver operating characteristic (ROC) curve analysis in a comparison between people with both KP and RKOA and normal controls.ResultsEffusion and synovial hypertrophy differed by gender but not by age or laterality, therefore gender-specific reference limits were estimated. However, the “normal” ranges between men and women were similar for effusion (0–10.3 mm vs 0–9.8 mm), but different for synovial hypertrophy (0–6.8 mm vs 0–5.4 mm). Power Doppler Signal (PDS) in the healthy controls was uncommon (1.2% in men and 0.0% in women). The optimal cut-off was 7.4 mm for men and 5.3 mm for women for effusion, and 3.7 and 1.6 for hypertrophy respectively. The high specificity cut-off was 8.9 for men and 7.8 for women for effusion, and 5.8 and 4.2 for hypertrophy respectively.ConclusionsUS effusion and synovial hypertrophy but not PDS are common, but differ by gender, in community-derived people without painful knee OA. Currently used cut-offs for abnormality need reappraisal.

The importance of synovial inflammation in osteoarthritis: current evidence from imaging assessments and clinical trials.

Synovial abnormalities have been observed at multiple stages of osteoarthritis (OA). Increasing evidence suggests that it may play an important role in the OA pathological process. Many assessment systems using magnetic resonance imaging (MRI) and ultrasound have been established to detect synovial inflammation in OA. These have been used to inform the current investigation of OA disease phenotypes and progression and can be utilised in the future for clinical trials developing potential treatments. This narrative review aims to illustrate the importance of synovial tissue in OA and provide an overview of imaging assessments and possible therapies targeting synovial abnormalities.

Delineating the Application of Ultrasound in Detecting Synovial Abnormalities of the Subtalar Joint in Juvenile Idiopathic Arthritis.

To investigate the frequency of ultrasound (US)-detectable involvement of the subtalar joint (STJ), to compare clinical versus US assessment of the STJ, and to compare different scanning approaches to the STJ in juvenile idiopathic arthritis (JIA). Clinical and US assessments were performed independently in 50 ankles with clinically active JIA. US abnormalities of the STJ were investigated using a lateral, medial, and posterior scanning approach and scored semiquantitatively. Agreement was tested using kappa statistics. A control group of 10 healthy subjects was examined. Clinical and US evaluations detected synovitis in 24 of 50 (48.0%) and 27 of 50 (54.0%) of STJs, respectively. US detected synovitis in 10 of 26 STJs (38.5%) recorded as normal on clinical evaluation, but was negative in 7 of 24 STJs (29.2%) diagnosed as having involvement on clinical examination. Agreement between clinical and US assessments was fair (κ = 0.32). US abnormalities were more frequently detectable using the lateral scanning approach. All patients with US abnormalities in the medial and/or posterior side of the STJ had also US abnormalities on the lateral scanning approach, but the reverse was not true. Intra- and interobserver agreements for the lateral scanning approach were satisfactory for both detecting involvement and scoring US abnormalities. None of the 17 STJs of healthy controls showed US abnormalities. US may increase the precision of the evaluation of the STJ in JIA. The observed high frequency of STJ involvement on US suggests to include this joint in US scanning protocols devised for children with JIA. Synovitis is more frequently detected using the lateral scanning approach.