Global burden of early-onset osteoarthritis, 1990-2019: results from the Global Burden of Disease Study 2019.

OBJECTIVES: Early-onset osteoarthritis (OA) is an emerging health issue amidst the escalating prevalence of overweight and obesity. However, there are scant data on its disease, economic burden and attributable burden due to high body mass index (BMI). METHODS: Using data from the Global Burden of Diseases Study 2019, we examined the numbers of incident cases, prevalent cases, years lived with disability (YLDs) and corresponding age-standardised rates for early-onset OA (diagnosis before age 55) from 1990 to 2019. The case definition was symptomatic and radiographically confirmed OA in any joint. The average annual percentage changes (AAPCs) of the age-standardised rates were calculated to quantify changes. We estimated the economic burden of early-onset OA and attributable burden to high BMI. RESULTS: From 1990 to 2019, the global incident cases, prevalent cases and YLDs of early-onset OA were doubled. 52.31% of incident OA cases in 2019 were under 55 years. The age-standardised rates of incidence, prevalence and YLDs increased globally and for countries in all Sociodemographic Index (SDI) quintiles (all AAPCs>0, p<0.05), with the fastest increases in low-middle SDI countries. 98.04% of countries exhibited increasing trends in all age-standardised rates. Early-onset OA accounts for US$46.17 billion in healthcare expenditure and US$60.70 billion in productivity loss cost in 2019. The attributable proportion of high BMI for early-onset OA increased globally from 9.41% (1990) to 15.29% (2019). CONCLUSIONS: Early-onset OA is a developing global health problem, causing substantial economic costs in most countries. Targeted implementation of cost-effective policies and preventive intervention is required to address the growing health challenge.

Comparative efficacy of exercise therapy and oral non-steroidal anti-inflammatory drugs and paracetamol for knee or hip osteoarthritis: a network meta-analysis of randomised controlled trials.

OBJECTIVE: Clinical guidelines recommend exercise as a core treatment for knee or hip osteoarthritis (OA). However, how its analgesic effect compares to analgesics, for example, oral non-steroidal anti-inflammatory drugs (NSAIDs) and paracetamol-the most commonly used analgesics for OA, remains unknown. DESIGN: Network meta-analysis. DATA SOURCES: PubMed, Embase, Scopus, Cochrane Library and Web of Science from database inception to January 2022. ELIGIBILITY CRITERIA FOR SELECTING STUDIES: Randomised controlled trials (RCTs) comparing exercise therapy with oral NSAIDs and paracetamol directly or indirectly in knee or hip OA. RESULTS: A total of n=152 RCTs (17 431 participants) were included. For pain relief, there was no difference between exercise and oral NSAIDs and paracetamol at or nearest to 4 (standardised mean difference (SMD)=-0.12, 95% credibility interval (CrI) -1.74 to 1.50; n=47 RCTs), 8 (SMD=0.22, 95% CrI -0.05 to 0.49; n=2 RCTs) and 24 weeks (SMD=0.17, 95% CrI -0.77 to 1.12; n=9 RCTs). Similarly, there was no difference between exercise and oral NSAIDs and paracetamol in functional improvement at or nearest to 4 (SMD=0.09, 95% CrI -1.69 to 1.85; n=40 RCTs), 8 (SMD=0.06, 95% CrI -0.20 to 0.33; n=2 RCTs) and 24 weeks (SMD=0.05, 95% CrI -1.15 to 1.24; n=9 RCTs). CONCLUSIONS: Exercise has similar effects on pain and function to that of oral NSAIDs and paracetamol. Given its excellent safety profile, exercise should be given more prominence in clinical care, especially in older people with comorbidity or at higher risk of adverse events related to NSAIDs and paracetamol.CRD42019135166.

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

OBJECTIVES: Knee 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. METHODS: Participants 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. RESULTS: In 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. CONCLUSION: In 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.

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

OBJECTIVE: 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. METHODS: 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. RESULTS: 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. CONCLUSION: 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.

Association Between Hyperuricemia and Ultrasound-Detected Hand Synovitis.

OBJECTIVE: Although hand synovitis is prevalent in the older population, the etiology remains unclear. Hyperuricemia, a modifiable metabolic disorder, may serve as an underlying mechanism of hand synovitis, but little is known about their relationship. We assessed the association between hyperuricemia and hand synovitis in a large population-based sample. METHODS: We performed a cross-sectional study in Longshan County, Hunan Province, China. Hyperuricemia was defined as a serum urate level >420 µmol/L in men and >360 µmol/L in women. Ultrasound examinations were performed on both hands of 4,080 participants, and both gray-scale synovitis and the Power Doppler signal (PDS) were assessed using semiquantitative scores (grades 0-3). We evaluated the association of hyperuricemia with hand gray-scale synovitis (grade ≥2) and PDS (grade ≥1), respectively, adjusting for age, sex, and body mass index. RESULTS: All required assessments for analysis were available for 3,286 participants. The prevalence of hand gray-scale synovitis was higher among participants with hyperuricemia (30.0%) than those with normouricemia (23.3%), with an adjusted odds ratio (aOR) of 1.28 (95% confidence interval [CI] 1.00-1.62). Participants with hyperuricemia also had a higher prevalence of PDS (aOR 2.36; 95% CI 1.15-4.81). Furthermore, hyperuricemia positively associated, both at the hand and joint levels, with the presence of gray-scale synovitis (aOR 1.27; 95% CI 1.00-1.60 and adjusted prevalence ratio [aPR] 1.26; 95% CI 1.10-1.44, respectively) and PDS (aOR 2.35; 95% CI 1.15-4.79 and aPR 2.34; 95% CI 1.28-4.30, respectively). CONCLUSION: This population-based study provides more evidence for a positive association between hyperuricemia and prevalent hand synovitis.

Bidirectional association identified between synovitis and knee and hand osteoarthritis: a general population-based study.

Background: Synovitis has long been considered a common and modifiable inflammatory feature of osteoarthritis (OA), but current disease-modifying anti-inflammatory treatments appear ineffective in OA clinical trials. Elucidating the temporal relationship between synovitis and OA could provide insight into the role of synovitis in OA. Methods: We conducted a prospective cohort study based on the baseline and three-year follow-up data from the Xiangya Osteoarthritis (XO) Study. We assessed bidirectional associations between ultrasound-detected synovitis and radiographic and symptomatic OA at knee and hand sites using generalized estimating equations. Additionally, we performed bidirectional Mendelian randomization (MR) analyses to test these hypotheses utilising whole-genome sequencing data in the XO population. Age, sex, body mass index, smoking, alcohol consumption, educational level, physical activity, and joint injury history were adjusted for these analyses. Findings: A total of 2211, 2420, 2280, and 2600 participants were enrolled for analyses of radiographic knee OA (RKOA), symptomatic knee OA (SKOA), radiographic hand OA (RHOA) and symptomatic hand OA (SHOA), respectively. The baseline synovitis (i.e., with synovitis vs. without synovitis) was associated with the incident RKOA (76/277 vs. 557/3674 knees), SKOA (49/387 vs. 287/4213 knees), RHOA (171/358 vs. 686/3664 hands) and SHOA (35/689 vs. 76/4327 hands), with adjusted odds ratio (aORs) of 2.2 (95% CI 1.7-3.1), 2.0 (1.3-2.9), 3.4 (2.7-4.4), and 2.4 (1.5-3.8), respectively. The baseline RKOA (with OA vs. without OA: 409/1246 vs. 481/3758 knees), SKOA (200/576 vs. 675/4356 knees), RHOA (192/778 vs. 410/3723 hands), and SHOA (41/162 vs. 548/4285 hands) were also associated with the incident synovitis, with aORs of 3.4 (95% CI 2.9-4.1), 2.7 (2.1-3.4), 2.3 (1.8-2.9) and 1.9 (1.2-2.8), respectively. These bidirectional associations were stronger when more active synovitis was compared with the reference group (all P < 0.05). MR analyses further supported bidirectional associations that synovitis significantly increased the odds of incident OA at both sites and vice versa (all ORs ranged from 1.2-1.7). Interpretation: Our population-based cohort study found novel evidence of a bidirectional association between synovitis and OA, which was further validated through MR analysis and suggested that the bidirectional association is likely causal. Our findings indicated that synovitis is both a risk factor and a consequence of the OA rather than solely a risk factor. Funding: The National Key Research and Development Plan, the National Natural Science Foundation of China, the Key Research and Development Program of Hunan Province, the Natural Science Foundation of Hunan Province, the Central South University Innovation-Driven Research Programme, and the Fundamental Research Funds for the Central Universities of Central South University.

Gut-joint axis in knee synovitis: gut fungal dysbiosis and altered fungi-bacteria correlation network identified in a community-based study.

OBJECTIVES: Knee synovitis is a highly prevalent and potentially curable condition for knee pain; however, its pathogenesis remains unclear. We sought to assess the associations of the gut fungal microbiota and the fungi-bacteria correlation network with knee synovitis. METHODS: Participants were derived from a community-based cross-sectional study. We performed an ultrasound examination of both knees. A knee was defined as having synovitis if its synovium was ≥4 mm and/or Power Doppler (PD) signal was within the knee synovium area (PD synovitis). We collected faecal specimens from each participant and assessed gut fungal and bacterial microbiota using internal transcribed spacer 2 and shotgun metagenomic sequencing. We examined the relation of α-diversity, ß-diversity, the relative abundance of taxa and the interkingdom correlations to knee synovitis. RESULTS: Among 977 participants (mean age: 63.2 years; women: 58.8%), 191 (19.5%) had knee synovitis. ß-diversity of the gut fungal microbiota, but not α-diversity, was significantly associated with prevalent knee synovitis. The fungal genus Schizophyllum was inversely correlated with the prevalence and activity (ie, control, synovitis without PD signal and PD synovitis) of knee synovitis. Compared with those without synovitis, the fungi-bacteria correlation network in patients with knee synovitis was smaller (nodes: 93 vs 153; edges: 107 vs 244), and the average number of neighbours was fewer (2.3 vs 3.2). CONCLUSION: Alterations of gut fungal microbiota and the fungi-bacteria correlation network are associated with knee synovitis. These novel findings may help understand the mechanisms of the gut-joint axis in knee synovitis and suggest potential targets for future treatment.

Diagnostic accuracy of ultrasound for the assessment of Baker's cysts: a meta-analysis.

BACKGROUND: Baker's cyst is the most common cystic disease of the knee, and a fast and accurate diagnosis of Baker's cyst is essential for a better management. Ultrasound is a rapid, portable, widely available, inexpensive and noninvasive imaging modality. However, the diagnostic accuracy of ultrasound on Baker's cyst still remains undetermined. We conducted the first meta-analysis to comprehensively assess the accuracy of ultrasound for the detection of Baker's cyst. METHODS: PubMed, Embase and Web of Science were searched from inception to July 14, 2022, without language restrictions. Studies providing cross-tabulations of ultrasound versus pathology (gold standard) or MRI (standard imaging technique) for diagnosis of Baker's cyst were included. Indicators for the diagnostic accuracy of ultrasound, including sensitivity, specificity and area under the curve, were calculated using a bivariate model. Sensitivity analysis was conducted to evaluate the heterogeneity and robustness of the results. RESULTS: A total of 13 studies with 1,011 subjects (mean age 32.2 years; men 53.5%) met the inclusion criteria. The pooled sensitivity, specificity and area under the curve of ultrasound for diagnosis of Baker's cyst, compared with pathology, were 0.97 (95% confidence intervals: 0.73-1.00), 1.00 (0.98-1.00) and 1.00 (0.99-1.00), respectively. The pooled estimates of ultrasound versus MRI were 0.94 (0.87-0.98) for sensitivity, 1.00 (0.83-1.00) for specificity and 0.97 (0.95-0.98) for area under the curve. Sensitivity analysis did not change the results materially. CONCLUSION: Ultrasound shows excellent diagnostic accuracy for the assessment of Baker's cyst and provides similar diagnostic information (absent or present) compared to MRI. Because of its advantages of low cost, portability and accessibility, ultrasound is likely to be a choice of imaging technique for screening Baker's cyst in clinical and population settings as well as in follow-ups.