The role of synovitis in pathophysiology and clinical symptoms of osteoarthritis

Osteoarthritis (OA), one of the most common rheumatic disorders, is characterized by cartilage breakdown and by synovial inflammation that is directly linked to clinical symptoms such as joint swelling, synovitis and inflammatory pain. The gold-standard method for detecting synovitis is histological analysis of samples obtained by biopsy, but the noninvasive imaging techniques MRI and ultrasonography might also perform well. The inflammation of the synovial membrane that occurs in both the early and late phases of OA is associated with alterations in the adjacent cartilage that are similar to those seen in rheumatoid arthritis. Catabolic and proinflammatory mediators such as cytokines, nitric oxide, prostaglandin E(2) and neuropeptides are produced by the inflamed synovium and alter the balance of cartilage matrix degradation and repair, leading to excess production of the proteolytic enzymes responsible for cartilage breakdown. Cartilage alteration in turn amplifies synovial inflammation, creating a vicious circle. As synovitis is associated with clinical symptoms and also reflects joint degradation in OA, synovium-targeted therapy could help alleviate the symptoms of the disease and perhaps also prevent structural progression.

Effect of Intra-articular Triamcinolone vs Saline on Knee Cartilage Volume and Pain in Patients With Knee Osteoarthritis: A Randomized Clinical Trial

IMPORTANCE

Synovitis is common and is associated with progression of structural characteristics of knee osteoarthritis. Intra-articular corticosteroids could reduce cartilage damage associated with synovitis but might have adverse effects on cartilage and periarticular bone.

OBJECTIVE

To determine the effects of intra-articular injection of 40 mg of triamcinolone acetonide every 3 months on progression of cartilage loss and knee pain.

DESIGN, SETTING, AND PARTICIPANTS

Two-year, randomized, placebo-controlled, double-blind trial of intra-articular triamcinolone vs saline for symptomatic knee osteoarthritis with ultrasonic features of synovitis in 140 patients. Mixed-effects regression models with a random intercept were used to analyze the longitudinal repeated outcome measures. Patients fulfilling the American College of Rheumatology criteria for symptomatic knee osteoarthritis, Kellgren-Lawrence grades 2 or 3, were enrolled at Tufts Medical Center beginning February 11, 2013; all patients completed the study by January 1, 2015.

INTERVENTIONS

Intra-articular triamcinolone (n = 70) or saline (n = 70) every 12 weeks for 2 years.

MAIN OUTCOMES AND MEASURES

Annual knee magnetic resonance imaging for quantitative evaluation of cartilage volume (minimal clinically important difference not yet defined), and Western Ontario and McMaster Universities Osteoarthritis index collected every 3 months (Likert pain subscale range, 0 [no pain] to 20 [extreme pain]; minimal clinically important improvement, 3.94).

RESULTS

Among 140 randomized patients (mean age, 58 [SD, 8] years, 75 women [54%]), 119 (85%) completed the study. Intra-articular triamcinolone resulted in significantly greater cartilage volume loss than did saline for a mean change in index compartment cartilage thickness of -0.21 mm vs -0.10 mm (between-group difference, -0.11 mm; 95% CI, -0.20 to -0.03 mm); and no significant difference in pain (-1.2 vs -1.9; between-group difference, -0.6; 95% CI, -1.6 to 0.3). The saline group had 3 treatment-related adverse events compared with 5 in the triamcinolone group and had a small increase in hemoglobin A1c levels (between-group difference, -0.2%; 95% CI, -0.5% to -0.007%).

CONCLUSIONS AND RELEVANCE

Among patients with symptomatic knee osteoarthritis, 2 years of intra-articular triamcinolone, compared with intra-articular saline, resulted in significantly greater cartilage volume loss and no significant difference in knee pain. These findings do not support this treatment for patients with symptomatic knee osteoarthritis.

TRIAL REGISTRATION

ClinicalTrials.gov Identifier: NCT01230424.

Bone edema scored on magnetic resonance imaging scans of the dominant carpus at presentation predicts radiographic joint damage of the hands and feet six years later in patients with rheumatoid arthritis

OBJECTIVE

Magnetic resonance imaging (MRI) is capable of revealing synovitis and tendinitis in early rheumatoid arthritis (RA), as well as bone edema and erosion. These features are visible before radiographic joint damage occurs. We sought to examine whether MRI of one body region (the wrist) can be used to predict whole-body radiography scores reflecting joint damage at 6 years.

METHODS

We conducted a 6-year prospective study of a cohort of patients who fulfilled the criteria for RA at presentation, using clinical parameters, radiographs, and MRI scans of the dominant wrist. Of the 42 patients enrolled at baseline, full MRI, radiographic, and clinical data were available for 31 at 6-year followup. MRI scans were scored by 2 radiologists, using a validated scoring system. Radiographs of the hands and feet were graded using the modified Sharp scoring method. MRI and radiography scores obtained at baseline and 6 years were compared, and baseline MRI scores were examined for their ability to predict radiographic outcome at 6 years.

RESULTS

At 6 years, the total Sharp score correlated significantly with the total MRI score and the MRI erosion score (r = 0.81, P < 0.0001 and r = 0.79, P < 0.0001, respectively). The 6-year Sharp score also correlated with the baseline total MRI and MRI erosion scores (r = 0.56, P < 0.0001 and r = 0.33, P = 0.03, respectively). MRI synovitis and bone edema scores remained constant for the group as a whole over 6 years, but bone erosion scores progressed (P = 0.0001), consistent with radiographic deterioration. Erosions on 6-year MRI scans were frequently preceded by MRI bone edema at baseline (odds ratio 6.5, 95% confidence interval 2.78-18.1). Regression models indicated that the baseline MRI bone edema score was predictive of the 6-year total Sharp score (P = 0.01), as was the C-reactive protein (CRP) level (P = 0.0002). Neither shared epitope status nor swollen or tender joint counts predicted radiographic outcome in this cohort. A model incorporating baseline MRI scores for erosion, bone edema, synovitis, and tendinitis plus the CRP level and the erythrocyte sedimentation rate explained 59% of the variance in the 6-year total Sharp score (R(2) = 0.59, adjusted R(2) = 0.44).

CONCLUSION

MRI scans performed at the first presentation of RA can be used to help predict future radiographic damage, allowing disease-modifying therapy to be targeted to patients with aggressive disease.

Longitudinal power Doppler ultrasonographic assessment of joint inflammatory activity in early rheumatoid arthritis: Predictive value in disease activity and radiologic progression

OBJECTIVE

To evaluate the sensitivity to change of power Doppler ultrasound (PDUS) assessment of joint inflammation and the predictive value of PDUS parameters in disease activity and radiologic outcome in patients with early rheumatoid arthritis (RA).

METHODS

Forty-two patients with early RA who started therapy with disease-modifying antirheumatic drugs underwent blinded sequential clinical, laboratory, and ultrasound assessment at baseline, 3 months, 6 months, and 1 year and radiographic assessment at baseline and 1 year. For each patient, 28-joint Disease Activity Score (DAS28) was recorded at each visit. The presence of synovitis was investigated in 28 joints using gray-scale ultrasonography and intraarticular power Doppler signal. Active synovitis was defined as intraarticular synovitis detected with power Doppler signal. The ultrasound joint count for active synovitis and an overall joint index for power Doppler signal were calculated. Sensitivity to change of PDUS variables was assessed by estimating the smallest detectable difference (SDD) from the intraobserver variability.

RESULTS

The SDD for ultrasound joint count for active synovitis and ultrasound joint index for power Doppler signal was lower than mean changes from baseline to 3 months, 6 months, and 1 year. Time-integrated values of PDUS parameters demonstrated a highly significant correlation with DAS28 after 1 year (r = 0.63, P < 0.001) and a stronger correlation with radiographic progression (r = 0.59-0.66, P < 0.001) than clinical and laboratory parameters (r < 0.5).

CONCLUSION

PDUS is a sensitive and reliable method for longitudinal assessment of inflammatory activity in early RA. PDUS findings may have a predictive value in disease activity and radiographic outcome.

Power Doppler ultrasonography for assessment of synovitis in the metacarpophalangeal joints of patients with rheumatoid arthritis: a comparison with dynamic magnetic resonance imaging

OBJECTIVE

To evaluate the effectiveness of power Doppler ultrasonography (PDUS) for assessing inflammatory activity in the metacarpophalangeal (MCP) joints of patients with rheumatoid arthritis (RA), using dynamic magnetic resonance imaging (MRI) as a reference method.

METHODS

PDUS and dynamic MRI were performed on 54 MCP joints of 15 patients with active RA and on 12 MCP joints of 3 healthy controls. PDUS was performed with a LOGIQ 500 unit by means of a 7-13-MHz linear array transducer. Later the same day, MRI was performed with a 1.0T MR unit. A series of 24 coronal T1-weighted images of the second through the fifth MCP joints was obtained, with intravenous injection of gadolinium diethylenetriaminepentaacetic acid after the fourth image (dynamic MRI). From the MR images, the rate of early synovial enhancement (RESE; defined as the relative enhancement per second during the first 55 seconds postinjection) was calculated and compared with the flow signal on PDUS, which was scored as present or absent.

RESULTS

In RA patients, flow signal on PDUS was detected in 17 of 54 MCP joints examined. Postcontrast MR images revealed an RESE of > or = 1.0%/second in 18 of 54 RA MCP joints. PDUS showed no flow in 47 of 48 MCP joints with an RESE of <1.0%/second and revealed flow in 16 of 18 MCP joints with an RESE of > or = 1.0%/second. Using dynamic MRI as a reference, PDUS had a sensitivity of 88.8% and a specificity of 97.9%.

CONCLUSION

PDUS was reliable for assessing inflammatory activity in the MCP joints of RA patients, using dynamic MRI as the standard. PDUS and clinical assessment of joint swelling/tenderness were only weakly correlated.

Should oligoarthritis be reclassified? Ultrasound reveals a high prevalence of subclinical disease

OBJECTIVE

To determine the prevalence of subclinical synovitis using ultrasound (US) imaging of both painful and asymptomatic joints, in patients with early (<12 months), untreated oligoarthritis (

METHODS

Eighty patients underwent a detailed clinical assessment by two physicians. All painful joints were identified, which were immediately scanned by a sonographer. In the last 40 patients, an additional standard group of joints was scanned to establish the prevalence of synovitis in asymptomatic joints.

RESULTS

In 80 patients, 644 painful joints (with and without clinical synovitis) were identified and each underwent a US assessment. Of these joints, 185 had clinical synovitis, of which, US detected synovitis in only 79% (147/185). In the other 38 joints US demonstrated tenosynovitis instead of synovitis in 12 joints and possible, but not definite, synovitis in 11 joints. Fifteen joints were, however, normal on US. In 459 joints that were not clinically synovitic, US detected synovitis in 33% (150/459). In 64% (51/80) of patients, US detected synovitis in more joints than clinical examination and in 36% (29/80) of patients, US detected a polyarthritis (>6 joints). Of the 826 asymptomatic (non-painful) joints scanned, 13% (107/826) had US detected synovitis.

CONCLUSION

Sonography detected more synovitis than clinical examination in patients with oligoarthritis. In almost two thirds of patients there was evidence of subclinical disease while one third could be reclassified as polyarticular. These findings suggest that a definition of oligoarthritis based purely on clinical findings may be inappropriate, which may have important implications for disease management.

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MESH Headings

• Adult
• Aged
• Aged, 80 and over
• Female
• Humans
• Male
• Middle Aged
• Pain Measurement/methods
• Physical Examination
• Prevalence
• Rheumatic Fever/classification
• Rheumatic Fever/diagnostic imaging
• Rheumatic Fever/epidemiology
• Synovitis/diagnostic imaging
• Synovitis/epidemiology
• Tenosynovitis/diagnostic imaging
• Ultrasonography

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Characteristic magnetic resonance imaging entheseal changes of knee synovitis in spondylarthropathy

OBJECTIVE

To use magnetic resonance imaging (MRI) in patients with rheumatoid arthritis (RA) and spondylarthropathy (SpA) to determine if the primary site of abnormality differs.

METHODS

Twenty patients with recent-onset knee effusion (10 with SpA and 10 with RA) were evaluated using fat-suppressed MRI. Knee joint effusion and synovitis were confirmed using ultrasonography. MRI scans were independently scored by 2 observers who were blinded to the patient's diagnosis.

RESULTS

All 10 of the SpA patients, but only 4 of the 10 RA patients, had focal peri-entheseal high signal (compatible with fluid or edema) outside the joint (P = 0.01). Six of the SpA patients had bone marrow edema that was maximal at entheseal insertions; in 4 cases this was multifocal. No RA patients showed such an abnormality (P = 0.01).

CONCLUSION

Prominent entheseal abnormalities on MRI are a consistent feature of new-onset synovitis in SpA, but are a minor feature of RA. This finding has important implications for the diagnosis, classification, and mechanisms of synovitis in patients with SpA.

Elucidation of the relationship between synovitis and bone damage: a randomized magnetic resonance imaging study of individual joints in patients with early rheumatoid arthritis

OBJECTIVE

To simultaneously image bone and synovium in the individual joints characteristically involved in early rheumatoid arthritis (RA).

METHODS

Forty patients with early, untreated RA underwent gadolinium-enhanced magnetic resonance imaging (MRI) of the second through fifth metacarpophalangeal joints of the dominant hand at presentation, 3 months, and 12 months. In the first phase (0-3 months), patients were randomized to receive either methotrexate alone (MTX) or MTX and intraarticular corticosteroids (MTX + IAST) into all joints with clinically active RA. The MTX-alone group received no further corticosteroids until the second phase (3-12 months), when both groups received standard therapy.

RESULTS

In the first phase, MTX + IAST reduced synovitis scores more than MTX alone. There were significantly fewer joints with new erosions on MRI in the former group compared with the latter. During the second phase, the synovitis scores were equivalent and a similar number of joints in each group showed new erosions on MRI. In both phases, there was a close correlation between the degree of synovitis and the number of new erosions, with the area under the curve for MRI synovitis the only significant predictor of bone damage progression. In individual joints, there was a threshold effect on new bone damage related to the level of synovitis; no erosions occurred in joints without synovitis.

CONCLUSION

In early RA, synovitis appears to be the primary abnormality, and bone damage occurs in proportion to the level of synovitis but not in its absence. In the treatment of patients with RA, outcome measures and therapies should focus on synovitis.

Synovitis in knee osteoarthritis: a precursor of disease?

OBJECTIVES

It is unknown whether joint inflammation precedes other articular tissue damage in osteoarthritis. Therefore, this study aims to determine if synovitis precedes the development of radiographic knee osteoarthritis (ROA).

METHODS

The participants in this nested case-control study were selected from persons in the Osteoarthritis Initiative with knees that had a Kellgren Lawrence grading (KLG)=0 at baseline (BL). These knees were evaluated annually with radiography and non-contrast-enhanced MRI over 4 years. MRIs were assessed for effusion-synovitis and Hoffa-synovitis. Case knees were defined by ROA (KLG≥2) on the postero-anterior knee radiographs at any assessment after BL. Radiographs were assessed at P0 (time of onset of ROA), 1 year prior to P0 (P-1) and at BL. Controls were participants who did not develop incident ROA (iROA) from BL to 48 months).

RESULTS

133 knees of 120 persons with ROA (83 women) were matched to 133 control knees (83 women). ORs for occurrence of iROA associated with the presence of effusion-synovitis at BL, P-1 and P0 were 1.56 (95% CI 0.86 to 2.81), 3.23 (1.72 to 6.06) and 4.7 (1.10 to 2.95), respectively. The ORs for the occurrence of iROA associated with the presence of Hoffa-synovitis at BL, P-1 and P0 were 1.80 (1.1 to 2.95), 2.47 (1.45 to 4.23) and 2.40 (1.43 to 4.04), respectively.

CONCLUSIONS

Effusion-synovitis and Hoffa-synovitis strongly predicted the development of iROA.

Magnetic resonance imaging findings in 84 patients with early rheumatoid arthritis: bone marrow oedema predicts erosive progression

OBJECTIVES

To examine the spectrum and severity of magnetic resonance imaging (MRI) findings in patients with early rheumatoid arthritis (RA), and to investigate the predictive value of MRI findings for subsequent development of conventional radiographic (CR) damage and MRI erosions.

METHODS

84 consecutive patients with RA with disease duration <1 year were enrolled. Patients were treated according to standard clinical practice, and evaluated at baseline, 3, 6 and 12 months by core measures of disease activity, conventional radiographs of both hands and wrists and MRI of the dominant wrist. MR images were scored according to the OMERACT rheumatoid arthritis magnetic resonance imaging score (RAMRIS), and conventional radiographs according to the van der Heijde modified Sharp score.

RESULTS

MRI findings reflecting inflammation (synovitis, bone marrow oedema and tenosynovitis) decreased during follow-up, while there was a small increase in MRI erosion score and CR damage. The proportion of patients with erosive progression at 1 year was 48% for conventional radiography and 66% for MRI. Baseline MRI bone marrow oedema (score >2 RAMRIS units) was identified as an independent predictor of both CR (odds ratio = 2.77 (95% confidence interval (CI) 1.06 to 7.21)) and MRI erosive progression (B = 0.21 (95% CI 0.08 to 0.34)).

CONCLUSIONS

MRI findings were common in early RA, and MRI bone marrow oedema was an independent predictor of radiographic damage. These results suggest that MRI scans of the dominant wrist may help clinicians to determine which patients need early and aggressive treatment to avoid subsequent joint damage.

Comparison of ultrasonographic assessment of synovitis and joint vascularity with radiographic evaluation in a randomized, placebo-controlled study of infliximab therapy in early rheumatoid arthritis

OBJECTIVE

To investigate sensitive ultrasonographic imaging methods for detection of synovial thickness and vascularity to discriminate between patients with early rheumatoid arthritis (RA) receiving infliximab + methotrexate (MTX) versus placebo + MTX over 18 weeks, and to compare the relationship between synovial thickening and vascularity at baseline and radiologic damage to joints of the hands and feet at 54 weeks.

METHODS

Patients with early RA (duration <3 years) receiving stable dosages of MTX were randomly assigned to receive blinded infusions of 5 mg/kg infliximab (n = 12) or placebo (n = 12) at weeks 0, 2, 6, and then every 8 weeks until week 46. At baseline and week 18, clinical assessments were performed, and metacarpophalangeal joints were assessed by high-frequency ultrasonography and power Doppler ultrasonography measurements. Radiographs of the hands and feet taken at baseline and at 54 weeks were evaluated using the van der Heijde modification of the Sharp method (vdH-Sharp score).

RESULTS

Using changes in the total vdH-Sharp score over 54 weeks and changes in synovial thickening and joint vascularity at 18 weeks, we were able to distinguish those patients receiving infusions of infliximab + MTX from those receiving placebo + MTX. Sonographic measurements of synovial thickening and vascularity at baseline in the placebo + MTX group demonstrated clear relationships with the magnitude of radiologic joint damage at week 54. Infliximab + MTX treatment abolished these relationships.

CONCLUSION

The delay or reversal of inflammatory and joint-destructive mechanisms in patients with early RA was already apparent following 18 weeks of treatment with infliximab + MTX and was reflected in radiologic changes at 54 weeks.

Pigmented villonodular synovitis of synovial joints: clinical, pathologic, and radiologic features

The clinical, pathologic, and radiologic features of pigmented villonodular synovitis of large synovial joints are presented. The typical plain-film presentation of this unusual entity is a noncalcified capsular soft-tissue mass of the knee, without bony abnormalities. When pigmented villonodular synovitis occurs in other joints, it is often accompanied by cystic bone erosions. This important radiographic finding might mislead one to an improper diagnosis of neoplasia or infection. This review reveals insufficient emphasis in the radiologic literature on the high incidence of bone lesions in joints affected by pigmented villonodular synovitis. A mechanism for the development of bone cysts is proposed. Clinical, pathologic, radiologic, and therapeutic considerations are discussed.

EULAR report on the use of ultrasonography in painful knee osteoarthritis. Part 1: prevalence of inflammation in osteoarthritis

OBJECTIVES

To assess the prevalence of inflammation in subjects with chronic painful knee osteoarthritis (OA), as determined by the presence of synovitis or joint effusion at ultrasonography (US); and to evaluate the correlation between synovitis, effusion, and clinical parameters.

METHODS

A cross sectional, multicentre, European study was conducted under the umbrella of EULAR-ESCISIT.

SUBJECTS

had primary chronic knee OA (ACR criteria) with pain during physical activity >or=30 mm for at least 48 hours. Clinical parameters were collected by a rheumatologist and an US examination of the painful knee was performed by a radiologist or rheumatologist within 72 hours of the clinical examination. Ultrasonographic synovitis was defined as synovial thickness >or=4 mm and diffuse or nodular appearance, and a joint effusion was defined as effusion depth >or=4 mm.

RESULTS

600 patients with painful knee OA were analysed. At US 16 (2.7%) had synovitis alone, 85 (14.2%) had both synovitis and effusion, 177 (29.5%) had joint effusion alone, and 322 (53.7%) had no inflammation according to the definitions employed. Multivariate analysis showed that inflammation seen by US correlated statistically with advanced radiographic disease (Kellgren-Lawrence grade >or=3; odds ratio (OR)=2.20 and 1.91 for synovitis and joint effusion, respectively), and with clinical signs and symptoms suggestive of an inflammatory "flare", such as joint effusion on clinical examination (OR=1.97 and 2.70 for synovitis and joint effusion, respectively) or sudden aggravation of knee pain (OR=1.77 for joint effusion).

CONCLUSION

US can detect synovial inflammation and effusion in painful knee OA, which correlate significantly with knee synovitis, effusion, and clinical parameters suggestive of an inflammatory "flare".

Power Doppler sonography of synovitis: assessment of therapeutic response--preliminary observations

Power Doppler sonography was used in eight symptomatic knees in seven patients with arthritis before and after joint aspiration and intraarticular administration of steroids. A qualitative decrease in synovial perfusion was observed in all eight knees, and symptoms improved in seven of the eight cases. These preliminary data suggest a role for power Doppler sonography in assessment of serial changes in synovial inflammation.

Doppler ultrasound and magnetic resonance imaging of synovial inflammation of the hand in rheumatoid arthritis: a comparative study

OBJECTIVE

To compare the quantitative and qualitative information obtained by Doppler ultrasound (US) measurements of the wrist joints and the small joints of the hand with the information obtained by postcontrast magnetic resonance imaging (MRI) and to correlate the imaging results with clinical observations in patients with rheumatoid arthritis (RA).

METHODS

Twenty-nine consecutive RA patients were studied; 196 joints (29 wrist and 167 finger joints) were examined by both US and MRI. Parameters of inflammation were the color fraction and the resistance index (RI) obtained with color Doppler US and the thickness of enhanced synovium (in mm) and the MRI score obtained with postcontrast MRI. Clinical examination and measurements of the erythrocyte sedimentation rate (ESR) and C-reactive protein (CRP) level were performed on the same day as the imaging studies.

RESULTS

There was a highly significant association between US indices of inflammation and postcontrast MRI scores. The mean values for both the color fraction and the RI were significantly different in the group without joint swelling compared with the other groups. The mean RI values were significantly different in the group without joint tenderness compared with the other groups. The mean thickness of enhanced synovium on postcontrast MRI was significantly different between the group without joint swelling and the other groups, but this difference was statistically significant only for the comparison of the group without joint tenderness versus the group with maximum tenderness. No association between the MRI or US estimates of inflammation and values on the visual analog scale for pain, Health Assessment Questionnaire, duration of morning stiffness, ESR, or CRP was found.

CONCLUSION

Estimates of synovial inflammatory activity by Doppler US and postcontrast MRI were comparable. Estimation of synovial inflammatory activity by the RI and color fraction parameters of US appears to be a promising method of detecting and monitoring inflammatory activity in patients with RA.

Should imaging be a component of rheumatoid arthritis remission criteria? A comparison between traditional and modified composite remission scores and imaging assessments

OBJECTIVES

Patients can fulfil clinical criteria for remission, yet still have evidence of synovitis detectable clinically and by ultrasound, and this is associated with structural damage. Stricter remission criteria may more accurately reflect true remission (no synovitis). This hypothesis was examined by studying patients using more stringent thresholds for clinical remission and determining their levels of ultrasound synovitis.

METHODS

Rheumatoid arthritis patients with a disease activity score in 28 joints (DAS28) ≤2.6 for at least 6 months were classified using standard and more stringent DAS28 and simplified disease activity index (SDAI) remission thresholds and the corresponding clinical and ultrasound imaging measures of synovitis recorded.

RESULTS

128 patients (all DAS28 <2.6, median DAS28 1.70) receiving either disease-modifying antirheumatic drugs alone (n=66) or with a tumour necrosis factor blocker (n=62) were recruited. Of the 640 imaged joints, 5% had moderate or severe power Doppler (PD) activity, 8% were clinically swollen and 1% tender. In patients fulfilling DAS28, American College of Rheumatology or SDAI remission criteria, moderate or severe PD activity was present in 21%, 15% and 19%, respectively. More stringent DAS28 and SDAI criteria reduced the mean number of swollen and tender joints (p<0.001) but not the percentage of patients with PD activity: 32 patients had a DAS28 <1.17 but eight (25%) had significant PD activity.

CONCLUSION

Using more stringent remission criteria resulted in reduced signs and symptoms of inflammation, but the percentage of joints with PD activity was not reduced, even in those without signs or symptoms. These data suggest that clinical criteria are sufficiently insensitive to detect low but clinically relevant levels of inflammation accurately.

Synovial thickening detected by MR imaging in osteoarthritis of the knee confirmed by biopsy as synovitis

Previous studies have established the value of magnetic resonance imaging (MRI) in detecting articular changes characteristic of osteoarthritis (OA) of the knee. We have observed some MRI features in OA of the knee presumably indicating synovial thickening. To determine whether these MR features represent chronic synovial inflammation, we studied the knees of nine patients at the mild end of the spectrum of OA of relatively short duration (89%: < or = 4 yr), who were selected because MRI showed anatomical abnormalities compatible with synovial thickening. The painful knee was examined using conventional and weight-bearing radiographs, MRI, and arthroscopy. MR images suggestive of synovial thickening typically appeared in or near the intercondylar region of the knee, in the infrapatellar fat pad, or in the posterior joint margin. The site of an arthroscopic biopsy of the synovial membrane was guided by MRI to the area thought to represent synovial thickening for each patient knee. Pathological examination of these synovial membrane biopsies showed a mild chronic synovitis, and thus a correspondence with the synovial thickening detected by MRI. Our results suggest that MRI can be used to evaluate the extent of synovitis, observed as synovial thickening, in patients with early OA of the knee.

Magnetic resonance imaging, radiography, and scintigraphy of the finger joints: one year follow up of patients with early arthritis. The TIRA Group

OBJECTIVES

To evaluate synovial membrane hypertrophy, tenosynovitis, and erosion development of the 2nd to 5th metacarpophalangeal (MCP) and proximal interphalangeal (PIP) joints by magnetic resonance imaging in a group of patients with rheumatoid arthritis (RA) or suspected RA followed up for one year. Additionally, to compare the results with radiography, bone scintigraphy, and clinical findings.

PATIENTS AND METHODS

Fifty five patients were examined at baseline, of whom 34 were followed up for one year. Twenty one patients already fulfilled the American College of Rheumatology (ACR) criteria for RA at baseline, five fulfilled the criteria only after one year's follow up, whereas eight maintained the original diagnosis of early unclassified polyarthritis. The following MRI variables were assessed at baseline and one year: synovial membrane hypertrophy score, number of erosions, and tenosynovitis score.

RESULTS

MRI detected progression of erosions earlier and more often than did radiography of the same joints; at baseline the MRI to radiography ratio was 28:4. Erosions were exclusively found in patients with RA at baseline or fulfilling the ACR criteria at one year. At one year follow up, scores of MR synovial membrane hypertrophy, tenosynovitis, and scintigraphic tracer accumulation had not changed significantly from baseline; in contrast, swollen and tender joint counts had declined significantly (p<0.05).

CONCLUSIONS

MRI detected more erosions than radiography. MR synovial membrane hypertrophy and scintigraphy scores did not parallel the changes seen over time in clinically assessed swollen and tender joint counts. Although joint disease activity may be assessed as quiescent by conventional clinical methods, a more detailed evaluation by MRI may show that a pathological condition is still present within the synovium.

Utility of ultrasound joint counts in the prediction of rheumatoid arthritis in patients with very early synovitis

OBJECTIVES

Early therapy improves outcomes in rheumatoid arthritis (RA). It is therefore important to improve predictive algorithms for RA in early disease. This study evaluated musculoskeletal ultrasound, a sensitive tool for the detection of synovitis and erosions, as a predictor of outcome in very early synovitis.

METHODS

58 patients with clinically apparent synovitis of at least one joint and symptom duration of ≤3 months underwent clinical, laboratory, radiographic and 38 joint ultrasound assessments and were followed prospectively for 18 months, determining outcome by 1987 American College of Rheumatology (ACR) and 2010 ACR/European League Against Rheumatism criteria. Sensitivity and specificity for 1987 RA criteria were determined for ultrasound variables and logistic regression models were then fitted to evaluate predictive ability over and above the Leiden rule.

RESULTS

16 patients resolved, 13 developed non-RA persistent disease and 29 developed RA by 1987 criteria. Ultrasound demonstrated subclinical wrist, elbow, knee, ankle and metatarsophalangeal joint involvement in patients developing RA. Large joint and proximal interphalangeal joint ultrasound variables had poor predictive ability, whereas ultrasound erosions lacked specificity. Regression analysis demonstrated that greyscale wrist and metacarpophalangeal joint involvement, and power Doppler involvement of metatarsophalangeal joints provided independently predictive data. Global ultrasound counts were inferior to minimal power Doppler counts, which significantly improved area under the curve values from 0.905 to 0.962 combined with the Leiden rule.

CONCLUSION

In a longitudinal study, extended ultrasound joint evaluation significantly increased detection of joint involvement in all regions and outcome groups. Greyscale and power Doppler scanning of metacarpophalangeal joints, wrists and metatarsophalangeal joints provides the optimum minimal ultrasound data to improve on clinical predictive models for RA.

Validation and reproducibility of ultrasonography in the detection of synovitis in the knee: A comparison with arthroscopy and clinical examination

OBJECTIVE

Accurate detection of synovitis is important in both the diagnosis and outcome assessment of arthritis. This study was undertaken to assess the validity and reproducibility of ultrasonography (US) as a means of detecting synovitis in the knee, by comparing US findings with findings of arthroscopy and clinical examination.

METHODS

Sixty consecutive patients with knee pain due to various arthritides had a clinical examination and US of their knee performed immediately prior to arthroscopy. All 3 assessments were performed by different clinicians who were blinded to the results obtained with the other modalities. US and clinical examination were compared with arthroscopically detected synovitis as the gold standard. Data from a subset of patients were used for calculating the inter- and intrareader reproducibility of US results, using a standard dichotomous (absence/presence of synovitis) as well as a graded (absence/grade of synovitis) scoring system.

RESULTS

With the use of arthroscopy as the gold standard, US had a higher sensitivity (98% versus 85%), specificity (88% versus 25%), accuracy (97% versus 77%), positive predictive value (98% versus 88%), and negative predictive value (88% versus 20%) compared with clinical examination. The Cohen kappa values for inter- and intrareader reproducibility of US for distinguishing between presence and absence of synovitis were 0.71 and 0.85, respectively (P < 0.05 for both). The weighted kappa values for distinguishing grade of synovitis were 0.65 for inter- and 0.74 for intrareader reproducibility. The kappa value for intrareader reproducibility of arthroscopy results was 0.88.

CONCLUSION

Ultrasonography is a valid and reproducible technique for detecting synovitis in the knee, and is more accurate than clinical examination. It may be valuable as a tool in studies investigating pain, diagnosis, and treatment response in knee arthritis.

Extraarticular snapping hip: sonographic findings

OBJECTIVE

The aim of the study was to determine the sonographic findings of snapping hip and to correlate the findings with the presence or absence of pain.

MATERIALS AND METHODS

Twenty patients with snapping hip were examined with sonography. Conventional and dynamic sonographic examinations of both hips were performed using a 5.0- or 7.0-MHz transducer.

RESULTS

Conventional sonographic studies allowed identification of various structural abnormalities (tendinitis, bursitis, synovitis) and helped to document tenderness along the course of specific tendons. Dynamic sonographic studies revealed 26 cases of snapping hip. In 24 of these 26 cases, the underlying cause was clearly identified. Twenty-two snapping hips were caused by an abnormal movement of the iliopsoas tendon, and two were caused by iliotibial band friction over the greater trochanter. One patient reported a bilateral snapping sensation that could not be documented on sonography. Snapping hip was elicited by a wide variety of hip movements. Sonography established an immediate temporal correlation between the jerky tendon motion and the painful snap reported by the patient. Only 14 cases of snapping hip were painful.

CONCLUSION

Conventional sonographic studies can identify signs of tendinitis, bursitis, or synovitis. Dynamic sonographic studies revealed the cause of snapping hip in most patients. Snapping hip is characterized on sonography by a sudden abnormal displacement of the snapping structure. In our study, a significant proportion of the cases of snapping hip were not painful.

Clinical improvement and radiological deterioration in rheumatoid arthritis: evidence that the pathogenesis of synovial inflammation and articular erosion may differ

The contrast between clinical improvement and radiological deterioration in rheumatoid arthritis (RA) is striking. We characterized this relationship using serial disease activity measures and radiographs of hands and feet in 40 RA patients observed over 6 yr. All disease activity measures improved, including grip strength, Ritchie index (RI), haemoglobin and erythrocyte sedimentation rate (ESR) (all P < 0.0001). In contrast, articular erosion increased (P < 0.0001). Radiological change during the study correlated with RI (r = 0.49), haemoglobin (r = -0.56) and ESR (r = 0.53). Radiological status at review also correlated with these variables (r = 0.36, -0.44 and 0.36, respectively). Articular erosion continues in RA despite clinical improvement and is accelerated in those with evidence of continuing synovial inflammation, reflected in clinical and laboratory measures of disease activity. Since many therapies in RA suppress inflammation, but not erosion, these findings suggest that the pathogenesis of articular erosion may differ from that of synovial inflammation.

Prospective 7 year follow up imaging study comparing radiography, ultrasonography, and magnetic resonance imaging in rheumatoid arthritis finger joints

OBJECTIVE

To perform a prospective long term follow up study comparing conventional radiography (CR), ultrasonography (US), and magnetic resonance imaging (MRI) in the detection of bone erosions and synovitis in rheumatoid arthritis (RA) finger joints.

METHODS

The metacarpophalangeal and proximal interphalangeal joints II-V (128 joints) of the clinically dominant hand of 16 patients with RA were included. Follow up joint by joint comparisons for erosions and synovitis were made.

RESULTS

At baseline, CR detected erosions in 5/128 (4%) of all joints, US in 12/128 (9%), and MRI in 34/128 (27%). Seven years later, an increase of joints with erosions was found with CR (26%), US (49%) (p<0.001 each), and MRI (32%, NS). In contrast, joint swelling and tenderness assessed by clinical examination were decreased at follow up (p = 0.2, p<0.001). A significant reduction in synovitis with US and MRI (p<0.001 each) was seen. In CR, 12 patients did not have any erosions at baseline, while in 10/12 patients erosions were detected in 25/96 (26%) joints after 7 years. US initially detected erosions in 9 joints, of which two of these joints with erosions were seen by CR at follow up. MRI initially found 34 erosions, of which 14 (41%) were then detected by CR.

CONCLUSION

After 7 years, an increase of bone erosions was detected by all imaging modalities. In contrast, clinical improvement and regression of synovitis were seen only with US and MRI. More than one third of erosions previously detected by MRI were seen by CR 7 years later.

Patients with RA in remission on TNF blockers: when and in whom can TNF blocker therapy be stopped?

OBJECTIVES

Combination therapy with methotrexate (MTX) and tumour necrosis factor (TNF) blockade has increased remission rates in patients with rheumatoid arthritis. However, there are no guidelines regarding cessation of therapy. There is a need for markers predictive of sustained remission following cessation of TNF blocker therapy.

METHODS

Patients in remission (DAS28 <2.6) treated with a TNF blocker and MTX as initial or delayed therapy were recruited. Joints were assessed for grey scale synovitis and power Doppler (PD) activity. Immunological assessment involved advanced six-colour flow cytometry.

RESULTS

Of the 47 patients recruited, 27 had received initial treatment and 20 delayed treatment with TNF blocking drugs. Two years after stopping TNF blocker therapy, the main predictor of successful cessation was timing of treatment; 59% of patients in the initial treatment group sustained remission compared with 15% in the delayed treatment group (p=0.003). Within the initial treatment group, secondary analysis showed that the only clinical predictor of successful cessation of treatment was shorter symptom duration before receiving treatment (median 5.5 months vs 9 months; p=0.008). No other clinical features were associated with successful cessation of therapy. Thirty-five per cent of patients had low PD activity but levels were not informative. Several immunological parameters were significantly associated with sustained remission including abnormal differentiation subset of T cells and regulatory T cells. Similar non-significant trends were observed in the delayed treatment group.

CONCLUSION

In patients in remission with low levels of imaging synovitis receiving combination treatment with a TNF blocker and MTX, immunological parameters and short duration of untreated symptoms were associated with successful cessation of TNF blocker therapy.

Clinical and ultrasonographic remission determines different chances of relapse in early and long standing rheumatoid arthritis

OBJECTIVES

Treatment of rheumatoid arthritis (RA) should aim at full remission. The aims of this study were to define: (1) how many patients reached ultrasound power Doppler (US-PD) remission in a cohort of patients with early RA (ERA) compared with longstanding RA (LSRA); (2) possible predictors of US-PD remission; and (3) how many patients with and without US-PD remission relapsed after 1 year of follow-up in ERA and LSRA.

METHODS

48 patients with ERA and 46 with LSRA with disease activity score <1.6 underwent US assessment. Six hand and wrist joints were studied for active synovitis. 56.2% of patients with ERA and 50.0% of those with LSRA fulfilled American College of Rheumatology (ACR) remission criteria.

RESULTS

43.7% of patients with ERA and 17.4% of those with LSRA had no evidence of synovitis at US evaluation. Using a stricter clinical definition of remission (ie, ACR criteria), US evaluation confirmed clinical remission in 66.7% of patients with ERA and 26.1% of those with LSRA. Early disease was predictive of clinical US remission. 20.0% of patients with RA who had a negative PD signal at the US evaluation had a flare during the 12-month follow-up period compared with 47.1% of patients who had a positive PD signal.

CONCLUSION

US-PD remission occurs in half of patients with ERA and in a minority of patients with LSRA in clinical remission. Early disease seems to be the major determinant of full remission.