Flare during tapering of biological DMARDs in patients with rheumatoid arthritis in routine care: characteristics and predictors.

OBJECTIVE: To identify predictors of flare in a 2-year follow-up study of patients with rheumatoid arthritis (RA) in sustained clinical remission tapering towards withdrawal of biological disease-modifying anti-rheumatic drugs (bDMARDs). METHODS: Sustained clinical remission was defined as Disease Activity Score for 28 joints (DAS28)-C reactive protein (CRP) ≤2.6 without radiographic progression for >1 year. bDMARDs were tapered according to a mandatory clinical guideline to two-thirds of standard dose at baseline, half of dose at week 16 and discontinuation at week 32. Prospective assessments for 2 years included clinical evaluation, conventional radiography, ultrasound and MRI for signs of inflammation and bone changes. Flare was defined as DAS28-CRP ≥2.6 with ∆DAS28-CRP ≥1.2 from baseline. Baseline predictors of flare were assessed by logistic regression analyses. RESULTS: Of 142 included patients, 121 (85%) flared during follow-up of which 86% regained remission within 24 weeks after flare. Patients that flared were more often rheumatoid factor positive, had tried more bDMARDs and had higher baseline ultrasound synovitis sum scores than those not flaring. For patients on standard dose, predictors of flare within 16 weeks after reduction to two-thirds of standard dose were baseline MRI-osteitis (OR 1.16; 95% CI 1.03 to 1.33; p=0.014), gender (female) (OR 6.71; 95% CI 1.68 to 46.12; p=0.005) and disease duration (OR 1.06; 95% CI 1.01 to 1.11; p=0.020). Baseline predictors for flare within 2 years were ultrasound grey scale synovitis sum score (OR 1.19; 95% CI 1.02 to 1.44; p=0.020) and number of previous bDMARDs (OR 4.07; 95% CI 1.35 to 24.72; p=0.007). CONCLUSION: The majority of real-world patients with RA tapering bDMARDs flared during tapering, with the majority regaining remission after stepwise dose increase. Demographic and imaging parameters (MR-osteitis/ultrasound greyscale synovitis) were independent predictors of immediate flare and flare overall and may be of importance for clinical decision-making in patients eligible for tapering.

Urate crystal deposition is associated with inflammatory markers and carotid artery pathology in patients with intercritical gout: results from the NOR-Gout study.

BACKGROUND: Gout is of unknown reason associated with cardiovascular disease. Ultrasound is sensitive for detecting crystal deposition and plasma calprotectin is a sensitive inflammatory marker. This study explores the associations between crystal deposition, inflammation and carotid artery pathology. METHOD: A cross-sectional analysis of baseline assessments from the NOR-Gout study was undertaken. Crystal deposition was assessed by ultrasound (double contour, tophi, aggregates) and dual-energy CT (DECT) and laboratory assessments included plasma calprotectin. The carotid arteries were bilaterally examined for carotid intima-media thickness (cIMT) and presence of plaques. Spearman correlations, Mann-Whitney tests and linear regression analyses were used to explore associations between crystal deposition, inflammatory markers,and carotid pathology. RESULTS: 202 patients with intercritical gout (95.5% men, mean (SD) age 56.5 (13.8) years, disease duration 7.9 (7.7) years) were included. Calprotectin was correlated with all scores of crystal deposition by ultrasound (r=0.26-0.32, p<0.001) and DECT (r=0.15, p<0.05). cIMT was correlated with sum score aggregates (r=0.18-0.22, p<0.05). Patients with large tophi had higher levels of calprotectin as well as more frequent carotid plaque (p<0.05). CONCLUSIONS: Study findings point towards crystal deposition contributing to subclinical inflammation with subsequent vascular implications. However, future longitudinal studies are needed to confirm such causal relationships.

The EANM guideline for radiosynoviorthesis.

PURPOSE: Radiosynoviorthesis (RSO) using the intraarticular application of beta-particle emitting radiocolloids has for decades been used for the local treatment of inflammatory joint diseases. The injected radiopharmaceuticals are phagocytized by the superficial macrophages of the synovial membrane, resulting in sclerosis and fibrosis of the formerly inflamed tissue, finally leading to reduced joint effusion and alleviation of joint pain. METHODS: The European Association of Nuclear Medicine (EANM) has written and approved these guidelines in tight collaboration with an international team of clinical experts, including rheumatologists. Besides clinical and procedural aspects, different national legislative issues, dosimetric considerations, possible complications, and side effects are addressed. CONCLUSION: These guidelines will assist nuclear medicine physicians in performing radiosynoviorthesis. Since there are differences regarding the radiopharmaceuticals approved for RSO and the official indications between several European countries, this guideline can only give a framework that must be adopted individually.

Accuracy of synovial fluid analysis compared to histology for the identification of calcium pyrophosphate crystals: an ancillary study of the OMERACT US Working Group - CPPD subgroup.

The aim of this study was to evaluate the accuracy of synovial fluid analysis in the identification of calcium pyrophosphate dihydrate crystals compared to microscopic analysis of joint tissues as the reference standard. This is an ancillary study of an international, multicentre cross-sectional study performed by the calcium pyrophosphate deposition disease (CPPD) subgroup of the OMERACT Ultrasound working group. Consecutive patients with knee osteoarthritis (OA) waiting for total knee replacement surgery were enrolled in the study from 2 participating centres in Mexico and Romania. During the surgical procedures, synovial fluid, menisci and hyaline cartilage were collected and analysed within 48 hours from surgery under transmitted light microscopy and compensated polarised light microscopy for the presence/absence of calcium pyrophosphate crystals. All slides were analysed by expert examiners on site, blinded to other findings. A dichotomic score (absence/ presence) was used for scoring both synovial fluid and tissues. Microscopic analysis of knee tissues was considered the gold standard. Sensitivity, specificity, accuracy, positive and negative predictive values of synovial fluid analysis in the identification of calcium pyrophosphate crystals were calculated. 15 patients (53% female, mean age 68 yo ± 8.4) with OA of grade 3 or 4 according to Kellgren-Lawrence scoring were enrolled. 12 patients (80%) were positive for calcium pyrophosphate crystals at the synovial fluid analysis and 14 (93%) at the tissue microscopic analysis. The overall diagnostic accuracy of synovial fluid analysis compared with histology for CPPD was 87%, with a sensitivity of 86% and a specificity of 100%, the positive predictive value was 100% and the negative predictive value was 33%. In conclusion synovial fluid analysis proved to be an accurate test for the identification of calcium pyrophosphate dihydrate crystals in patients with advanced OA.

Structural damage in rheumatoid arthritis assessed by musculoskeletal ultrasound: A systematic literature review by the Structural Joint Damage Task Force of the OMERACT Ultrasound Working Group.

OBJECTIVES: To identify and synthesize the evidence for the use and measurement properties of musculoskeletal ultrasound in assessing structural joint damage in patients with rheumatoid arthritis (RA). METHODS: A systematic literature search (SLR) of the PubMed, Embase and Cochrane Library was performed. Original articles were included published in English reporting on ultrasound of bone erosion, cartilage damage and the measurement properties of ultrasound according to the OMERACT filter 2.1. RESULTS: Of the 1.495 identified articles 149 were included in the final review, most of which reported on cross-sectional studies and used the OMERACT definitions for ultrasonographic pathology. Among these, bone erosions were assessed in 139 (93.3%), cartilage damage in 24 (16.1%), enthesophytes in 8 (5.4%), osteophytes in 15 (10.1%) and malalignment and ankylosis in a single (0.9%) study, respectively. Most studies (126/149, 84.6%) assessed the joints of the hands. The overwhelming majority of studies (127/149, 85.2%) assessed structural joint damage bilaterally. Validity, reliability and responsiveness were assessed in 21 (14.1%), 34 (22.8%) and 17 (11.4%) studies, respectively. CONCLUSION: While the results of this SLR suggest that ultrasound is a sensitive, reliable and feasible tool to detect damage in RA, they also highlight the need for further research and validation. Findings of this SLR will inform the next steps of the OMERACT Ultrasound Working Group in developing an ultrasound score for assessing structural joint damage in patients with RA.

Major reduction of ultrasound-detected synovitis during subcutaneous tocilizumab treatment: results from a multicentre 24 week study of patients with rheumatoid arthritis.

Objective: Few studies have investigated the efficacy of subcutaneous tocilizumab (TCZ-SC) on ultrasound-detected inflammation. This study aimed to explore the clinical efficacy of TCZ-SC treatment in rheumatoid arthritis (RA) patients and to evaluate the response by ultrasound compared to Composite Disease Activity Scores (CDAS).Method: This open-label, single-arm study enrolled RA patients with inadequate response to conventional synthetic disease-modifying anti-rheumatic drugs initiating TCZ-SC 162 mg once weekly for 24 weeks, with clinical assessments at baseline, 2, 4, 8, 12, 16, 20, and 24 weeks. Ultrasound examinations [semi-quantitative score (0-3) of 36 joints and four tendons] were performed at baseline, 4, 12, and 24 weeks. CDAS and American College of Rheumatology/European League Against Rheumatism (ACR/EULAR) response, and sum scores of ultrasound grey scale/Doppler were calculated. Changes during follow-up were explored by the Mann-Whitney test and correlations by Spearman's rho.Results: In total, 133 patients (mean ± sd age 55.9 ± 12.0 years) were assessed clinically and 110 patients were also examined with ultrasound. All clinical and ultrasound scores decreased significantly after 4 weeks (p < 0.001). At 24 weeks there was EULAR good response in 87.7% and ACR 70% response in 47.4%. Ultrasound scores had no or low correlations with patient-reported outcomes. At 24 weeks, CDAS remission was achieved in 27.4-83.5% and a sum score Doppler of 0 was found in 53.3%.Conclusions: Clinical and ultrasound scores decreased rapidly. Ultrasound scores were not associated with patient-reported variables. Half of the patients reached ultrasound remission, while there were large discrepancies in the percentage of patients reaching remission based on different CDAS.Trial registration: Study ML28691, registered 28 January 2014, ClinicalTrials.gov identifier: NCT02046616.

Evaluation of three scoring methods for Fluorescence Optical Imaging in erosive hand osteoarthritis and rheumatoid arthritis.

Objective: Fluorescence Optical Imaging (FOI) demonstrates indocyanine green (ICG)-enhanced microcirculation in wrist and finger joints, as a sign of inflammation. We wanted to assess the reliability of three FOI scoring methods from Berlin, Stockholm, and Copenhagen, to assess the validity of FOI with MRI as reference and to compare enhancement in hand joints in erosive hand osteoarthritis (OA) vs. rheumatoid arthritis (RA). Design: Five readers scored all finger and wrist joints of 26 patients with erosive hand OA and RA on semi-quantitative 0-3 scales using three different FOI scoring methods. To evaluate inter-reader reliability, we calculated the intraclass correlation coefficients (ICC) for sum scores and prevalence and bias adjusted kappa values for ordinal scales (Pabak-OS) on joint level. Enhancement in joint groups in erosive hand OA vs. RA was compared using Mann-Whitney test. Sensitivities and specificities of FOI was calculated with MRI as reference for hand OA patients only. Results: We found moderate to good inter-reader reliability for all FOI scoring methods (Pabak-OS: 0.50-0.78, ICC: 0.43-0.85) and different patterns of enhancement in erosive hand OA vs. RA with significantly more FOI enhancement in DIP joints in erosive hand OA across all methods. With MRI as reference the different FOI scoring methods reached similar sensitivities (63-65%) and specificities (76-91%). Conclusion: FOI enhancement can be measured reliably in erosive hand OA and RA using three different scoring methods. More DIP enhancement in erosive hand OA patients and good agreement with MRI support the diagnostic performance of FOI.

Implementation and role of modern musculoskeletal imaging in rheumatological practice in member countries of EULAR.

Objectives: To document the current training, implementation and role of modern musculoskeletal imaging techniques: ultrasound, magnetic resonance imaging, computed tomography and positron emission tomography, among rheumatologists in the member countries of the EULAR. Methods: English-language questionnaires for each imaging modality developed by a EULAR task force were sent out to national and international scientific societies as well as imaging experts in the given modalities involved in research and/or training. The surveys were distributed via an online survey tool (SurveyMonkey). Simple descriptive and summary statistics were calculated from the responses. Results: More than 90% of ultrasound (US) experts reported the availability of a US unit in their department. Suspicion of rheumatoid arthritis and spondyloarthritides were the main clinical indications for performing US for diagnostic purposes. Suspicion of sacroiliitis and degenerative spine disease were the most common indications to perform magnetic resonance imaging (MRI) or computed tomography (CT) for diagnostic purposes, while positron emission tomography was mainly performed to diagnose large vessel vasculitis and to investigate fever of unknown origin. The reported percentage of rheumatologists performing US was highly variable, ranging from more than 80% in 6% of countries to less than 10% in 15% of countries. The majority of experts (77%) reported that their national rheumatology societies organise musculoskeletal US courses, while courses in MRI or CT organised by the national rheumatology societies were less commonly reported (29% and 8%, respectively). Conclusions: Rheumatologists in Europe utilise modern imaging techniques; however, access to the techniques and training offered is varied.

Settings and artefacts relevant for Doppler ultrasound in large vessel vasculitis.

Ultrasound is used increasingly for diagnosing large vessel vasculitis (LVV). The application of Doppler in LVV is very different from in arthritic conditions. This paper aims to explain the most important Doppler parameters, including spectral Doppler, and how the settings differ from those used in arthritic conditions and provide recommendations for optimal adjustments. This is addressed through relevant Doppler physics, focusing, for example, on the Doppler shift equation and how angle correction ensures correctly displayed blood velocity. Recommendations for optimal settings are given, focusing especially on pulse repetition frequency (PRF), gain and Doppler frequency and how they impact on detection of flow. Doppler artefacts are inherent and may be affected by the adjustment of settings. The most important artefacts to be aware of, and to be able to eliminate or minimize, are random noise and blooming, aliasing and motion artefacts. Random noise and blooming artefacts can be eliminated by lowering the Doppler gain. Aliasing and motion artefacts occur when the PRF is set too low, and correct adjustment of the PRF is crucial. Some artefacts, like mirror and reverberation artefacts, cannot be eliminated and should therefore be recognised when they occur. The commonly encountered artefacts, their importance for image interpretation and how to adjust Doppler setting in order to eliminate or minimize them are explained thoroughly with imaging examples in this review.

Monitoring total-body inflammation and damage in joints and entheses: the first follow-up study of whole-body magnetic resonance imaging in rheumatoid arthritis.

OBJECTIVE: To investigate changes in whole-body magnetic resonance imaging (WBMRI) inflammatory and structural lesions in most joints and entheses in patients with rheumatoid arthritis (RA) treated with adalimumab. METHODS: WBMRI was obtained at weeks 0, 6, 16, and 52 in a 52 week follow-up study of 37 RA patients starting treatment with adalimumab. Readability and reliability of WBMRI were investigated for 76 peripheral joints, 23 discovertebral units, the sacroiliac joints, and 33 entheses. Changes in WBMRI joint and entheses counts were investigated. RESULTS: The readability of peripheral and axial joints was 82-100%, being less for elbows and small joints of the feet. For entheses, 72-100% were readable, except for entheses at the anterior chest wall, elbow, knee, and plantar fascia. The intrareader agreement was high for bone marrow oedema (BMO), bone erosion (80-100%), and enthesitis (77-100%), and slightly lower for synovitis and soft tissue inflammation (50-100%). All synovitis, BMO, and soft tissue inflammation counts decreased numerically during treatment. The 26-joint synovitis WBMRI count decreased significantly during the first 16 weeks for patients with a good European League Against Rheumatism (EULAR) response (from median 6 to 4, p < 0.05), but not for patients with a moderate or no EULAR response. There were no overall changes in structural lesions. CONCLUSIONS: WBMRI allows simultaneous monitoring of most axial and peripheral joints and entheses in RA patients and can visualize a decrease in inflammatory counts during treatment. This first WBMRI follow-up study of patients with RA encourages further investigation of the usefulness of WBMRI in RA.

Atlas-based knee osteophyte assessment with ultrasonography and radiography: relationship to arthroscopic degeneration of articular cartilage.

OBJECTIVES: To investigate intra- and inter-reader agreement of ultrasonography (US) and conventional radiography (CR) for the evaluation of osteophyte presence and size within the tibiofemoral joint. In addition, to correlate these findings with arthroscopic degeneration of the articular cartilage. METHOD: Forty adult patients with knee pain were enrolled in this study. Knee CR and US scanning of the medial and lateral bone margins were performed on all patients. A novel atlas for the US grading of knee osteophytes was used in the evaluation. The number and size of the osteophytes were evaluated semi-quantitatively in two rounds from both the CR images (four readers) and the US images (14 readers). The Noyes grading system was used for the evaluation of arthroscopic degeneration of the articular cartilage in 26 patients. RESULTS: On average, intra- and inter-reader US and CR agreement was substantial and comparable to each other (κ = 0.60-0.72). US detected more osteophytes than CR at both the medial (65% vs. 48%) and lateral (70% vs. 60%) compartments. A statistically significant correlation between CR- or US-based osteophyte and arthroscopy grades was observed only for US at the medial compartment (rs = 0.747, p < 0.001). CONCLUSIONS: The detection of knee osteophytes using the novel US atlas is as reproducible as reading conventional radiographs. US is more sensitive to detect knee osteophytes than CR. Furthermore, osteophytes detected with US correlate significantly with arthroscopic cartilage changes at the medial knee compartment whereas those detected by CR do not.

Educational recommendations for the conduct, content and format of EULAR musculoskeletal ultrasound Teaching the Teachers Courses.

OBJECTIVE: To produce educational guidelines for the conduct, content and format of theoretical and practical teaching at EULAR musculoskeletal ultrasound (MSUS) Teaching the Teachers (TTT) Courses. METHODS: A Delphi-based procedure with 24 recommendations covering five main areas (Duration and place of the course; Faculty members; Content of the course; Evaluation of the teaching skills; TTT competency assessment) was distributed among a group of experts involved in MSUS teaching, in addition to an advisory educational expert being present. Consensus for each recommendation was considered achieved when the percentage of agreement was >75%. RESULTS: 21 of 24 invited participants responded to the first Delphi questionnaire (88% response rate). All 21 participants also responded to the second round. Agreement on 19 statements was obtained after two rounds. CONCLUSIONS: This project has led to the development of guidelines for the conduct, content and format of teaching at the EULAR MSUS TTT Courses that are organised annually, with the aim of training future teachers of EULAR MSUS Courses, EULAR Endorsed MSUS Courses, as well as national and local MSUS Courses. The presented work gives indications on how to homogenise the teaching at the MSUS TTT Courses, thus resolving current discrepancies in the field.

EULAR recommendations for the use of imaging in the diagnosis and management of spondyloarthritis in clinical practice.

A taskforce comprised of an expert group of 21 rheumatologists, radiologists and methodologists from 11 countries developed evidence-based recommendations on the use of imaging in the clinical management of both axial and peripheral spondyloarthritis (SpA). Twelve key questions on the role of imaging in SpA were generated using a process of discussion and consensus. Imaging modalities included conventional radiography, ultrasound, magnetic resonance imaging, computed tomography (CT), positron emission tomography, single photon emission CT, dual-emission x-ray absorptiometry and scintigraphy. Experts applied research evidence obtained from systematic literature reviews using MEDLINE and EMBASE to develop a set of 10 recommendations. The strength of recommendations (SOR) was assessed by taskforce members using a visual analogue scale. A total of 7550 references were identified in the search process, from which 158 studies were included in the systematic review. Ten recommendations were produced using research-based evidence and expert opinion encompassing the role of imaging in making a diagnosis of axial SpA or peripheral SpA, monitoring inflammation and damage, predicting outcome, response to treatment, and detecting spinal fractures and osteoporosis. The SOR for each recommendation was generally very high (range 8.9-9.5). These are the first recommendations which encompass the entire spectrum of SpA and evaluate the full role of all commonly used imaging modalities. We aimed to produce recommendations that are practical and valuable in daily practice for rheumatologists, radiologists and general practitioners.

Ultrasonographic abnormalities and inter-reader reliability in Danish patients with systemic lupus erythematosus - a comparison with clinical examination of wrist and metacarpophalangeal joints.

OBJECTIVES: We aimed to determine 1) ultrasound (US) abnormalities in patients with systemic lupus erythematosus (SLE) with and without hand arthralgia at the day of examination compared with clinical evaluation and healthy controls, and 2) inter-observer reliability of the US abnormalities. METHODS: Thirty-three female SLE patients were twice examined with US by three trained examiners. Using B-mode and Doppler US, unilateral wrist and metacarpophalangeal (MCP) joints were examined for synovitis and erosions as well as signs of hand tenosynovitis using a GE Logiq 9 US machine with Doppler settings for slow flow. All patients also underwent clinical joint evaluation and were compared with 11 healthy controls (HC). RESULTS: Among the patients with SLE 16 (48%) had signs of wrist synovitis, which was only observed in one HC (p = 0.03). Corresponding figures for any MCP joint were 12 (36%) and 0 (p = 0.06). In SLE patients, 18% had hand tenosynovitis and 6% bone erosions. Wrist synovitis was detected by US in 16 SLE patients (81%) with arthralgia compared with 17 patients without (18%) (p = 0.0005). Any US abnormalities were observed in 44% of 25 wrists without tenderness at clinical examination and in 46% of 26 wrists without swelling. Corresponding percentages for MCP2 joints were 27% and 21%. Inter-observer reliability of the US findings was good to excellent for examination of hand joints and tendons. CONCLUSIONS: A majority of SLE patients with hand arthralgia showed US signs of synovitis, erosions and tenosynovitis indicating subclinical disease. Even SLE patients without clinical signs of joint inflammation demonstrated US abnormalities. Good to excellent inter-observer reliability was found in US evaluation of hands in patients with SLE.

Defining enthesitis in spondyloarthritis by ultrasound: results of a Delphi process and of a reliability reading exercise.

OBJECTIVE: To standardize ultrasound (US) in enthesitis. METHODS: An initial Delphi exercise was undertaken to define US-detected enthesitis and its core components. These definitions were subsequently tested on static images taken from spondyloarthritis patients in order to evaluate their reliability. RESULTS: Excellent agreement (>80%) was obtained for including hypoechogenicity, increased thickness of the tendon insertion, calcifications, enthesophytes, erosions, and Doppler activity as core elementary lesions of US-detected enthesitis. US definitions were subsequently obtained for each elementary component. On static images, the intraobserver reliability showed a high degree of variability for the detection of elementary lesions, with kappa coefficients ranging from 0.13-1. The interobserver kappa values were variable, with the lowest kappa coefficient for enthesophytes (0.24) and the highest coefficient for Doppler activity at the enthesis (0.63). CONCLUSION: This is the first consensus-based US definition of enthesitis and its elementary components and the first step performed to ensure a higher degree of homogeneity and comparability of results between studies and in daily clinical work.

EFSUMB minimum training requirements for rheumatologists performing musculoskeletal ultrasound.

In order to optimize and standardize musculoskeletal ultrasonography education for rheumatologists, there is a need for competency assessments addressing the required training and practical and theoretical skills. This paper describes how these competency assessments for rheumatologists were developed and what they contain.

Ultrasound evaluation of fluid in knee recesses at varying degrees of flexion.

OBJECTIVE: Various methods are utilized in daily practice to obtain optimal information on effusion in the knee. Our aim is to investigate which scanning position provides the best information about synovial fluid in the knee by using ultrasound and to evaluate the magnitude of difference for measuring synovial fluid in 3 major recesses (suprapatellar, medial parapatellar, and lateral parapatellar) of the knee according to various degrees of flexion. METHODS: Sonographers in 14 European centers documented bilateral knee joint ultrasound examinations on a total of 148 knee joints. The largest sagittal diameter of fluid was measured in scans corresponding to the 3 major recesses at different (0°, 15°, 30°, 45°, 60°, and 90°) degrees of flexion of the knee. The difference of measurement of effusion according to transducer position, knee position, and the interaction between them was investigated by analysis of variance followed by Tukey's test. RESULTS: No correlation was noted between patient characteristics and ultrasound detection of effusion. The sagittal diameter of synovial fluid in all 3 recesses was greatest at 30° flexion. Analysis of variance and Tukey's test revealed that the suprapatellar scan and 30° flexion is the best combination for detecting effusion as confirmed by receiver operator characteristic curve analysis. CONCLUSION: The suprapatellar scan of the knee in 30° flexion was the most sensitive position to detect fluid in knee joints. Sagittal diameter of fluid in all 3 recesses increased with the knee in the 30° flexed position as compared to the extended position.

Which knee and probe position determines the final diagnosis of knee inflammation by ultrasound? Results from a European multicenter study.

PURPOSE: To investigate which knee and probe position best identifies knee inflammation and to determine a cut-off level for abnormal synovial effusion. MATERIALS AND METHODS: 18 experienced sonographers (all rheumatologists) performed ultrasound examinations of the knee joint in patients with knee symptoms and in healthy controls. Each sonographer performed longitudinal suprapatellar ultrasound scans using 9 different configurations at each knee: Midline, parapatallar lateral and parapatellar medial from midline in neutral position (0°) with and without quadriceps muscle contraction and in 30° flexion of the knee. The presence of synovial effusion (SE), the effusion measured in millimeters and the presence of synovial hypertrophy (SH) was noted. RESULTS: A total of 298 knees of 149 subjects (129 patients and 20 controls) were examined. The detection of SH is more sensitive and specific than the detection of SE, independently of the knee and probe position, for the final diagnosis of abnormality. The detection of both synovial hypertrophy and effusion in the knee in neutral position (0°) with quadriceps contraction and with the probe in the midline position, are the best independent predictors for knee abnormalities. Knee effusion > 3.2 mm measured with the probe in the lateral aspect of the knee is the best diagnostic characteristics for predicting pathological SE. CONCLUSION: The best combination for detecting SH and SE is obtained by placing the probe in the midline position with the knee in 0° with quadriceps contraction. A cut-off value for pathological effusion may be obtained in the lateral aspect of the knee.