Reliability and agreement of proton density-weighted vs. gadolinium-enhanced T1-weighted MRI in hand osteoarthritis. An OMERACT MRI special interest group reliability exercise.

OBJECTIVES: To compare reliabilities of assessing synovitis in hand osteoarthritis (OA) using Magnetic Resonance Imaging (MRI) with/without gadolinium (Gd). METHODS: Three readers scored synovitis on non-enhanced two-dimensional (2D) proton density (PD)-weighted MRI and Gd-enhanced (3D) MRI of hand joints in 20 patients. Inter-reader reliabilities were examined. RESULTS: Reliability was good for Gd-enhanced MRI, but poor for non-enhanced PD-weighted MRI (intraclass correlation coefficient 0.83 and 0.21, respectively). Agreement between the two sequences was poor (weighted kappa 0.18). CONCLUSION: Gd-enhanced MRI was more reliable than PD-weighted MRI for assessing synovitis. Gd-enhancement, but also resolution and tissue contrast, might have contributed to this.

Effect of late prophylaxis in hemophilia on joint status: a randomized trial.

Essentials High-quality data are lacking on use of prophylaxis in adults with hemophilia and arthropathy. SPINART was a 3-year randomized clinical trial of late/tertiary prophylaxis vs on-demand therapy. Prophylaxis improved function, quality of life, activity and pain but not joint structure by MRI. Prophylaxis improves function but must start before joint bleeding onset to prevent arthropathy. SUMMARY: Background Limited data exist on the impact of prophylaxis on adults with severe hemophilia A and pre-existing joint disease. Objectives To describe 3-year bleeding, joint health and structure, health-related quality-of-life (HRQoL) and other outcomes from the open-label, randomized, multinational SPINART study. Patients/Methods Males aged 12-50 years with severe hemophilia A, ≥ 150 factor VIII exposure days, no inhibitors and no prophylaxis for > 12 consecutive months in the past 5 years were randomized to sucrose-formulated recombinant FVIII prophylaxis or on-demand therapy (OD). Data collected included total and joint bleeding events (BEs), joint structure (magnetic resonance imaging [MRI]), joint health (Colorado Adult Joint Assessment Scale [CAJAS]), HRQoL, pain, healthcare resource utilization (HRU), activity, and treatment satisfaction. Results Following 3 years of prophylaxis, adults maintained excellent adherence, with a 94% reduction in BEs despite severe pre-existing arthropathy; 35.7% and 76.2% of prophylaxis participants were bleed-free or had fewer than two BEs per year, respectively. As compared with OD, prophylaxis was associated with improved CAJAS scores (least squares [LS] mean, - 0.31 [n = 42] versus + 0.63 [n = 42]) and HAEMO-QoL-A scores (LS mean, + 3.98 [n = 41] versus - 6.00 [n = 42]), less chronic pain (50% decrease), and approximately two-fold less HRU; activity, Euro QoL-5D-3L (EQ-5D-3L) scores and satisfaction scores also favored prophylaxis. However, MRI score changes were not different for prophylaxis versus OD (LS mean, + 0.79 [n = 41] versus + 0.96 [n = 38]). Conclusions Over a period of 3 years, prophylaxis versus OD in adults with severe hemophilia A and arthropathy led to decreased bleeding, pain, and HRU, better joint health, activity, satisfaction, and HRQoL, but no reduction in structural arthropathy progression, suggesting that pre-existing joint arthropathy may be irreversible.

OARSI Clinical Trials Recommendations: Knee imaging in clinical trials in osteoarthritis.

Significant advances have occurred in our understanding of the pathogenesis of knee osteoarthritis (OA) and some recent trials have demonstrated the potential for modification of the disease course. The purpose of this expert opinion, consensus driven exercise is to provide detail on how one might use and apply knee imaging in knee OA trials. It includes information on acquisition methods/techniques (including guidance on positioning for radiography, sequence/protocol recommendations/hardware for magnetic resonance imaging (MRI)); commonly encountered problems (including positioning, hardware and coil failures, sequences artifacts); quality assurance (QA)/control procedures; measurement methods; measurement performance (reliability, responsiveness, validity); recommendations for trials; and research recommendations.

OARSI Clinical Trials Recommendations: Hand imaging in clinical trials in osteoarthritis.

Tremendous advances have occurred in our understanding of the pathogenesis of hand osteoarthritis (OA) and these are beginning to be applied to trials targeted at modification of the disease course. The purpose of this expert opinion, consensus driven exercise is to provide detail on how one might use and apply hand imaging assessments in disease modifying clinical trials. It includes information on acquisition methods/techniques (including guidance on positioning for radiography, sequence/protocol recommendations/hardware for MRI); commonly encountered problems (including positioning, hardware and coil failures, sequences artifacts); quality assurance/control procedures; measurement methods; measurement performance (reliability, responsiveness, validity); recommendations for trials; and research recommendations.

OARSI Clinical Trials Recommendations: Hip imaging in clinical trials in osteoarthritis.

Imaging of hip in osteoarthritis (OA) has seen considerable progress in the past decade, with the introduction of new techniques that may be more sensitive to structural disease changes. The purpose of this expert opinion, consensus driven recommendation is to provide detail on how to apply hip imaging in disease modifying clinical trials. It includes information on acquisition methods/techniques (including guidance on positioning for radiography, sequence/protocol recommendations/hardware for magnetic resonance imaging (MRI)); commonly encountered problems (including positioning, hardware and coil failures, artifacts associated with various MRI sequences); quality assurance/control procedures; measurement methods; measurement performance (reliability, responsiveness, and validity); recommendations for trials; and research recommendations.

What is the predictive value of MRI for the occurrence of knee replacement surgery in knee osteoarthritis?

Knee osteoarthritis is associated with structural changes in the joint. Despite its many drawbacks, radiography is the current standard for evaluating joint structure in trials of potential disease-modifying osteoarthritis drugs. MRI is a non-invasive alternative that provides comprehensive imaging of the whole joint. Frequently used MRI measurements in knee osteoarthritis are cartilage volume and thickness; others include synovitis, synovial fluid effusions, bone marrow lesions (BML) and meniscal damage. Joint replacement is considered a clinically relevant outcome in knee osteoarthritis; however, its utility in clinical trials is limited. An alternative is virtual knee replacement on the basis of symptoms and structural damage. MRI may prove to be a good alternative to radiography in definitions of knee replacement. One of the MRI parameters that predicts knee replacement is medial compartment cartilage volume/thickness, which correlates with radiographic joint space width, is sensitive to change, and predicts outcomes in a continuous manner. Other MRI parameters include BML and meniscal lesions. MRI appears to be a viable alternative to radiography for the evaluation of structural changes in knee osteoarthritis and prediction of joint replacement.

Sustained disease remission and inhibition of radiographic progression in methotrexate-naive patients with rheumatoid arthritis and poor prognostic factors treated with abatacept: 2-year outcomes.

OBJECTIVE: To assess the efficacy and safety of abatacept plus methotrexate versus methotrexate alone in early erosive rheumatoid arthritis (RA). METHODS: The AGREE was a 2-year phase IIIb multinational study in early (≤ 2 years) RA. During the double-blind period (year 1), patients were randomly assigned 1:1 to receive abatacept+methotrexate or methotrexate alone; all patients received open-label abatacept+methotrexate during year 2. Clinical outcomes assessed included 28-joint disease activity score (DAS28) defined remission, low disease activity score (LDAS), American College of Rheumatology (ACR) responses and physical function. Radiographic outcomes were assessed using the Genant-modified Sharp total score (TS). Safety was monitored throughout. RESULTS: Of the 459 patients completing year 1, 433 patients (94.3%) completed year 2. DAS28-defined remission, LDAS, ACR and physical function were sustained through year 2 in the original abatacept+methotrexate group, with 55.2% in remission at 2 years. Upon introduction of abatacept in the methotrexate-alone group, additional patients achieved DAS28-defined remission (44.5% vs 26.9%), LDAS (60.4% vs 43.2%) and improved ACR 70 (49.8% vs 31.7%) for year 2 versus year 1. Less radiographic progression was observed at 2 years in the original abatacept+methotrexate group than the methotrexate-alone group (change in TS 0.84 vs 1.75, p<0.001). No new safety issues were seen. Similar rates of serious adverse events, serious infections and autoimmune events were observed in years 1 and 2. CONCLUSIONS: The AGREE trial was the first to examine the impact of T-cell co-stimulation modulation with abatacept in patients with early erosive RA. Early treatment with abatacept+methotrexate resulted in greater sustainable clinical, functional and radiographic benefits than methotrexate alone, with acceptable safety and tolerability. TRIAL REGISTRATION: NCT00122382.

Inhibition of joint damage and improved clinical outcomes with rituximab plus methotrexate in early active rheumatoid arthritis: the IMAGE trial.

OBJECTIVES: Rituximab is an effective treatment in patients with established rheumatoid arthritis (RA). The objective of the IMAGE study was to determine the efficacy of rituximab in the prevention of joint damage and its safety in combination with methotrexate (MTX) in patients initiating treatment with MTX. METHODS: In this double-blind randomised controlled phase III study, 755 MTX-naïve patients with active RA were randomly assigned to MTX alone, rituximab 2×500 mg + MTX or rituximab 2×1000 mg + MTX. The primary end point at week 52 was the change in joint damage measured using a Genant-modified Sharp score. RESULTS: 249, 249 and 250 patients were randomly assigned to MTX alone, rituximab 2×500 mg + MTX or rituximab 2×1000 mg + MTX, respectively. At week 52, treatment with rituximab 2×1000 mg + MTX compared with MTX alone was associated with a reduction in progression of joint damage (mean change in total modified Sharp score 0.359 vs 1.079; p=0.0004) and an improvement in clinical outcomes (ACR50 65% vs 42%; p<0.0001); rituximab 2×500 mg + MTX improved clinical outcomes (ACR50 59% vs 42%; p<0.0001) compared with MTX alone but did not significantly reduce the progression of joint damage. Safety outcomes were similar between treatment groups. CONCLUSIONS: Treatment with rituximab 2×1000 mg in combination with MTX is an effective therapy for the treatment of patients with MTX-naïve RA. ClinicalTrials.gov identifier NCT00299104.

Denosumab-mediated increase in hand bone mineral density associated with decreased progression of bone erosion in rheumatoid arthritis patients.

OBJECTIVE: Periarticular osteoporosis is one of the earliest radiographic signs of bone damage in rheumatoid arthritis (RA). Denosumab, an investigational fully human monoclonal antibody that binds to RANKL, inhibits bone erosion and systemic bone loss in clinical studies of patients with RA. In this hand bone mineral density (BMD) substudy, we investigated the effects of denosumab on hand BMD and its correlation with hand erosion scores. METHODS: Patients receiving methotrexate for erosive RA were randomized in a 1:1:1 ratio to receive subcutaneous placebo, denosumab 60 mg, or denosumab 180 mg at 0 and 6 months. Measurements included BMD (by dual x-ray absorptiometry [DXA]) of both hands (0, 1, 6, and 12 months), magnetic resonance images of the hands/wrists (0 and 6 months), and radiographs of the hands/wrists and feet (0, 6, and 12 months). RESULTS: There were 56 patients (13 placebo, 21 denosumab 60 mg, and 22 denosumab 180 mg). Mean changes in hand BMD at 6 and 12 months were: +0.8% and +1.0%, respectively, for denosumab 60 mg; +2.0% and +2.5%, respectively, for denosumab 180 mg; and -1.2% and -2.0%, respectively, for placebo. Erosion scores remained near baseline in the denosumab groups and increased from baseline in the placebo group. A negative correlation was observed between hand BMD and erosion scores. CONCLUSION: In patients with RA, denosumab provided protection against erosion, and not only prevented bone loss but increased hand BMD as measured by DXA.

Impact of T-cell costimulation modulation in patients with undifferentiated inflammatory arthritis or very early rheumatoid arthritis: a clinical and imaging study of abatacept (the ADJUST trial).

BACKGROUND: Several agents provide treatment for established rheumatoid arthritis (RA), but a crucial therapeutic goal is to delay/prevent progression of undifferentiated arthritis (UA) or very early RA. OBJECTIVE: To determine the impact of T-cell costimulation modulation in patients with UA or very early RA. METHODS: In this double-blind, phase II, placebocontrolled, 2-year study, anti-cyclic citrullinated peptide (CCP)2-positive patients with UA (not fulfilling the ACR criteria for RA) and clinical synovitis of two or more joints were randomised to abatacept ( approximately 10 mg/kg) or placebo for 6 months; the study drug was then terminated. The primary end point was development of RA (by ACR criteria) at year 1. Patients were monitored by radiography, MRI, CCP2, rheumatoid factor and 28 joint count Disease Activity Score (DAS28) over 2 years. RESULTS: At year 1, 12/26 (46%) abatacept-treated versus 16/24 (67%) placebo-treated patients developed RA (difference (95% CI) -20.5% (-47.4% to 7.8%)). Adjusted mean changes from baseline to year 1 in Genant-modified Sharp radiographic scores for abatacepttreated versus placebo-treated patients, respectively, were 0 versus 1.1 for total score, and 0 versus 0.9 for erosion score. Mean changes from baseline to year 1 in MRI erosion, osteitis and synovitis scores were 0, 0.2 and 0.2, respectively, versus 5.0, 6.7 and 2.3 in the abatacept versus placebo groups. Safety was comparable between groups; serious adverse events occurred in one patient (3.6%) in each group. CONCLUSION: Abatacept delayed progression of UA/very early RA in some patients. An impact on radiographic and MRI inhibition was seen, which was maintained for 6 months after treatment stopped. This suggests that it is possible to alter the progression of RA by modulating T-cell responses at a very early stage of disease. Trial registration number NCT00124449.

Clinical efficacy and safety of abatacept in methotrexate-naive patients with early rheumatoid arthritis and poor prognostic factors.

OBJECTIVES: To assess the efficacy and safety of abatacept in methotrexate-naive patients with early rheumatoid arthritis (RA) and poor prognostic factors. METHODS: In this double-blind, phase IIIb study, patients with RA for 2 years or less were randomly assigned 1 : 1 to receive abatacept (approximately 10 mg/kg) plus methotrexate, or placebo plus methotrexate. Patients were methotrexate-naive and seropositive for rheumatoid factor (RF), anti-cyclic citrullinated protein (CCP) type 2 or both and had radiographic evidence of joint erosions. The co-primary endpoints were the proportion of patients achieving disease activity score in 28 joints (DAS28)-defined remission (C-reactive protein) and joint damage progression (Genant-modified Sharp total score; TS) at year 1. Safety was monitored throughout. RESULTS: At baseline, patients had a mean DAS28 of 6.3, a mean TS of 7.1 and mean disease duration of 6.5 months; 96.5% and 89.0% of patients were RF or anti-CCP2 seropositive, respectively. At year 1, a significantly greater proportion of abatacept plus methotrexate-treated patients achieved remission (41.4% vs 23.3%; p<0.001) and there was significantly less radiographic progression (mean change in TS 0.63 vs 1.06; p = 0.040) versus methotrexate alone. Over 1 year, the frequency of adverse events (84.8% vs 83.4%), serious adverse events (7.8% vs 7.9%), serious infections (2.0% vs 2.0%), autoimmune disorders (2.3% vs 2.0%) and malignancies (0.4% vs 0%) was comparable for abatacept plus methotrexate versus methotrexate alone. CONCLUSIONS: In a methotrexate-naive population with early RA and poor prognostic factors, the combination of abatacept and methotrexate provided significantly better clinical and radiographic efficacy compared with methotrexate alone and had a comparable, favourable safety profile.

Rituximab inhibits structural joint damage in patients with rheumatoid arthritis with an inadequate response to tumour necrosis factor inhibitor therapies.

OBJECTIVE: To determine if treatment with a B cell-targeted therapy can inhibit the progression of structural joint damage in patients with rheumatoid arthritis (RA), exhibiting an inadequate response to tumour necrosis factor (TNF) inhibitors. METHODS: In this phase III study, patients with an inadequate response to a TNF inhibitor and receiving methotrexate were randomised to rituximab or placebo. Radiographs were obtained at baseline, week 24 and week 56 after randomisation. Patients with an inadequate response to their randomised therapy could receive rescue medication from week 16. From week 24, eligible patients from both treatment arms could receive open-label rituximab. Patients were analysed according to their original treatment group. Radiographs were scored using the Genant-modified Sharp method. The primary radiographic endpoint was change in total Genant-modified Sharp score at week 56. RESULTS: Rituximab treatment caused significant reduction in joint damage progression compared with placebo. The mean change from baseline in the total Genant-modified Sharp score at week 56 was significantly lower for patients treated with rituximab than for patients treated with placebo (1.00 vs 2.31; p = 0.005), and was supported by changes in erosion score (0.59 and 1.32 for rituximab plus methotrexate vs placebo plus methotrexate, respectively; p = 0.011) and joint space narrowing score (0.41 and 0.99, respectively; p<0.001). CONCLUSIONS: This study provides the first evidence that a B cell-targeted therapy-rituximab-can significantly inhibit the progression of structural joint damage in patients with RA with long-standing, active and treatment-resistant disease.

The osteoarthritis initiative: report on the design rationale for the magnetic resonance imaging protocol for the knee.

OBJECTIVES: To report on the process and criteria for selecting acquisition protocols to include in the osteoarthritis initiative (OAI) magnetic resonance imaging (MRI) study protocol for the knee. METHODS: Candidate knee MR acquisition protocols identified from the literature were first optimized at 3Tesla (T). Twelve knees from 10 subjects were scanned one time with each of 16 acquisitions considered most likely to achieve the study goals and having the best optimization results. The resultant images and multi-planar reformats were evaluated for artifacts and structural discrimination of articular cartilage at the cartilage-fluid, cartilage-fat, cartilage-capsule, cartilage-meniscus and cartilage-cartilage interfaces. RESULTS: The five acquisitions comprising the final OAI MRI protocol were assembled based on the study goals for the imaging protocol, the image evaluation results and the need to image both knees within a 75 min time slot, including positioning. For quantitative cartilage morphometry, fat-suppressed, 3D dual-echo in steady state (DESS) acquisitions appear to provide the best universal cartilage discrimination. CONCLUSIONS: The OAI knee MRI protocol provides imaging data on multiple articular structures and features relevant to knee OA that will support a broad range of existing and anticipated measurement methods while balancing requirements for high image quality and consistency against the practical considerations of a large multi-center cohort study. Strengths of the final knee MRI protocol include cartilage quantification capabilities in three planes due to multi-planar reconstruction of a thin slice, high spatial resolution 3D DESS acquisition and the multiple, non-fat-suppressed image contrasts measured during the T2 relaxation time mapping acquisition.

An explanation for the apparent dissociation between clinical remission and continued structural deterioration in rheumatoid arthritis.

OBJECTIVE: Achieving remission is the aim of treatment in rheumatoid arthritis (RA). This should represent minimal arthritis activity and ensure optimal disease outcome. However, we have previously demonstrated a high prevalence of imaging-detected synovial inflammation in RA patients who were in clinical remission. The purpose of this study was to evaluate the long-term significance of subclinical synovitis and its relationship to structural outcome. METHODS: We studied 102 RA patients receiving conventional treatment who had been judged by their consultant rheumatologist to be in remission, as well as 17 normal control subjects. Subjects underwent clinical, laboratory, functional, and quality of life assessments over 12 months. In addition to standard radiography of the hands and feet, imaging of the hands and wrists was performed with musculoskeletal ultrasonography (US) and conventional 1.5 T magnetic resonance imaging (MRI) at baseline and 12 months, using validated acquisition and scoring techniques. RESULTS: Despite their being in clinical remission, 19% of the patients displayed deterioration in radiographic joint damage over the study period. Scores on musculoskeletal US synovial hypertrophy, power Doppler (PD), and MRI synovitis assessments in individual joints at baseline were significantly associated with progressive radiographic damage (P=0.032, P<0.001, and P=0.002, respectively). Furthermore, there was a significant association between the musculoskeletal US PD score at baseline and structural progression over 12 months in totally asymptomatic metacarpophalangeal joints (P=0.004) and 12 times higher odds of deterioration in joints with increased PD signal (odds ratio 12.21, P<0.001). CONCLUSION: Subclinical joint inflammation detected by imaging techniques explains the structural deterioration in RA patients in clinical remission who are receiving conventional therapy. Our findings reinforce the utility of imaging for the accurate evaluation of disease status and the prediction of structural outcome.

Abatacept inhibits progression of structural damage in rheumatoid arthritis: results from the long-term extension of the AIM trial.

OBJECTIVE: Assess the effect of abatacept on progression of structural damage over 2 years in patients with rheumatoid arthritis who had an inadequate response to methotrexate. METHODS: 539 patients entered an open-label extension of the AIM (Abatacept in Inadequate responders to Methotrexate) trial and received abatacept. Radiographic assessment of the hands and feet was performed at baseline, year 1 and year 2. At year 2, each patient's radiographs were scored for progression blinded to sequence and treatment allocation. RESULTS: In patients treated with abatacept for 2 years, greater reduction in progression of structural damage was observed in year 2 than in year 1. The mean change in total Genant-modified Sharp scores was reduced from 1.07 units in year 1 to 0.46 units in year 2. Similar reductions were observed in erosion and joint space narrowing scores. Following 2 years of treatment with abatacept, 50% of patients had no progression of structural damage as defined by a change in the total score of < or =0 compared with baseline. 56% of patients treated with abatacept had no progression during the first year compared with 45% of patients treated with placebo. In their second year of treatment with abatacept, more patients had no progression than in the first year (66% vs 56%). CONCLUSIONS: Abatacept has a sustained effect that inhibits progression of structural damage. Furthermore, the mean change in radiographic progression in patients treated with abatacept for 2 years was significantly lower in year 2 versus year 1, suggesting that abatacept may have an increasing disease-modifying effect on structural damage over time.

Longitudinal study of magnetic resonance imaging and standard X-rays to assess disease progression in osteoarthritis.

OBJECTIVE: To investigate, over 1-year, the relationship between X-ray and magnetic resonance imaging (MRI) findings in patients with knee osteoarthritis (OA). METHODS: Sixty-two osteoarthritic patients (46 women) were followed for 1 year. At baseline and after 1 year, volume and thickness of cartilage of the medial tibia, the lateral tibia and the femur were assessed by MRI. A global score from the multi-feature whole-organ MRI scoring system (WORMS) was calculated for each patient at baseline and after 1 year. This score combined individual scores for articular cartilage, osteophytes, bone marrow abnormality, subchondral cysts and bone attrition in 14 locations. It also incorporated scores for the medial and lateral menisci, anterior and posterior cruciate ligaments, medial and lateral collateral ligaments and synovial distension. Lateral and medial femoro-tibial joint space width (JSW) measurements, performed by digital image analysis, were assessed from fixed-flexion, postero-anterior knee radiographs. RESULTS: One-year changes in medial femoro-tibial JSW reach 6.7 (20.5) % and changes in medial cartilage volume and thickness reach 0.4 (16.7) % and 2.1 (11.3) %, respectively. Medial femoro-tibial joint space narrowing (JSN) after 1 year, assessed by radiography, was significantly correlated with a loss of medial tibial cartilage volume (r=0.25, P=0.046) and medial tibial cartilage thickness (r=0.28, P=0.025), over the same period. We found also a significant correlation between the progression of the WORMS and radiographic medial JSN over 1 year (r=-0.35, P=0.006). All these results remained statistically significant after adjusting for age, sex and body mass index. CONCLUSION: This study shows a moderate but significant association between changes in JSW and changes in cartilage volume or thickness in knee joint of osteoarthritic patients.

Presence of significant synovitis in rheumatoid arthritis patients with disease-modifying antirheumatic drug-induced clinical remission: evidence from an imaging study may explain structural progression.

OBJECTIVE: More timely and effective therapy for rheumatoid arthritis (RA) has contributed to increasing rates of clinical remission. However, progression of structural damage may still occur in patients who have satisfied remission criteria, which suggests that there is ongoing disease activity. This questions the validity of current methods of assessing remission in RA. The purpose of this study was to test the hypothesis that modern joint imaging improves the accuracy of remission measurement in RA. METHODS: We studied 107 RA patients receiving disease-modifying antirheumatic drug therapy who were judged by their consultant rheumatologist to be in remission and 17 normal control subjects. Patients underwent clinical, laboratory, functional, and quality of life assessments. The Disease Activity Score 28-joint assessment and the American College of Rheumatology remission criteria, together with strict clinical definitions of remission, were applied. Imaging of the hands and wrists using standardized acquisition and scoring techniques with conventional 1.5T magnetic resonance imaging (MRI) and ultrasonography (US) were performed. RESULTS: Irrespective of which clinical criteria were applied to determine remission, the majority of patients continued to have evidence of active inflammation, as shown by findings on the imaging assessments. Even in asymptomatic patients with clinically normal joints, MRI showed that 96% had synovitis and 46% had bone marrow edema, and US showed that 73% had gray-scale synovial hypertrophy and 43% had increased power Doppler signal. Only mild synovial thickening was seen in 3 of the control subjects (18%), but no bone marrow edema. CONCLUSION: Most RA patients who satisfied the remission criteria with normal findings on clinical and laboratory studies had imaging-detected synovitis. This subclinical inflammation may explain the observed discrepancy between disease activity and outcome in RA. Imaging assessment may be necessary for the accurate evaluation of disease status and, in particular, for the definition of true remission.

MRI protocols for whole-organ assessment of the knee in osteoarthritis.

One of the critical challenges in developing structure-modifying therapies for arthritis, especially osteoarthritis (OA), is measuring changes in progression of joint destruction. Magnetic resonance imaging (MRI) offers considerable promise in this regard. Not only can MRI quantify articular cartilage volume and morphology with high precision and accuracy, but it can also examine several other important articular components, and thus offer a unique opportunity to evaluate the knee and other joints as whole organs. On December 5 and 6, 2002, OMERACT (Outcome Measures in Rheumatology Clinical Trials) and OARSI (Osteoarthritis Research Society International), with support from various pharmaceutical companies listed at the beginning of this supplement, held a Workshop for Consensus on Osteoarthritis Imaging in Bethesda, MD. The aim of the Workshop was to provide a state-of-the-art review of imaging outcome measures for OA of the knee to help guide scientists and pharmaceutical companies who want to use MRI in multi-site studies of OA. Applications of MRI were initially reviewed by a multidisciplinary, international panel of expert scientists and physicians from academia, the pharmaceutical industry and regulatory agencies. The findings of the panel were then presented to a wider group of participants for open discussion. The following report summarizes the results of these discussions with respect to MRI acquisition techniques for whole-organ assessment of the knee in OA. The discussion reviews the selection and qualification of imaging sites for clinical trials, designing imaging protocols for whole-organ assessment of OA, and key considerations in image quality (IQ) control and data management.

Assessment of the radioanatomic positioning of the osteoarthritic knee in serial radiographs: comparison of three acquisition techniques.

OBJECTIVE: Recent studies using various standardized radiographic acquisition techniques have demonstrated the necessity of reproducible radioanatomic alignment of the knee to assure precise measurements of medial tibiofemoral joint space width (JSW). The objective of the present study was to characterize the longitudinal performance of several acquisition techniques with respect to long-term reproducibility of positioning of the knee, and the impact of changes in positioning on the rate and variability of joint space narrowing (JSN). METHODS: Eighty subjects were randomly selected from each of three cohorts followed in recent studies of the radiographic progression of knee osteoarthritis (OA): the Health ABC study (paired fixed-flexion [FF] radiographs taken at a 36-month interval); the Glucosamine Arthritis Intervention Trial (GAIT) (paired metatarsophalangeal [MTP] radiographs obtained at a 12-month interval), and a randomized clinical trial of doxycycline (fluoroscopically assisted semiflexed anteroposterior (AP) radiographs taken at a 16-month interval). Manual measurements were obtained from each radiograph to represent markers of radioanatomic positioning of the knee (alignment of the medial tibial plateau and X-ray beam, knee rotation, femorotibial angle) and to evaluate minimum JSW (mJSW) in the medial tibiofemoral compartment. The effects on the mean annualized rate of JSN and on the variability of that rate of highly reproduced vs variable positioning of the knee in serial radiographs were evaluated. RESULTS: Parallel or near-parallel alignment was achieved significantly more frequently with the fluoroscopically guided positioning used in the semiflexed AP protocol than with either the non-fluoroscopic FF or MTP protocol (68% vs 14% for both FF and MTP protocols when measured at the midpoint of the medial compartment; 75% vs 26% and 34% for the FF and MTP protocols, respectively, when measured at the site of mJSW; P<0.001 for each). Knee rotation was reproduced more frequently in semiflexed AP radiographs than in FF radiographs (66% vs 45%, P<0.01). In contrast, the FF technique yielded a greater proportion of paired radiographs in which the femorotibial angle was accurately reproduced than the semiflexed AP or MTP protocol (78% vs 59% and 56%, respectively, P<0.01 for each). Notably, only paired radiographs with parallel or near-parallel alignment exhibited a mean rate of JSN (+/-SD) in the OA knee that was more rapid and less variable than that measured in all knees (0.186+/-0.274 mm/year, standardized response to mean [SRM]=0.68 vs 0.128+/-0.291 mm/year, SRM=0.44). CONCLUSION: This study confirms the importance of parallel radioanatomic alignment of the anterior and posterior margins of the medial tibial plateau in detecting JSN in subjects with knee OA. The use of radiographic methods that assure parallel alignment during serial X-ray examinations will permit the design of more efficient studies of biomarkers of OA progression and of structure modification in knee OA.

Comparison of fixed flexion, fluoroscopic semi-flexed and MTP radiographic methods for obtaining the minimum medial joint space width of the knee in longitudinal osteoarthritis trials.

OBJECTIVE: To compare three radiographic techniques (fluoroscopic semi-flexed [Fluoro], fixed flexion [FF], and semi-flexed metatarsophalangeal joint [MTP] views) for measuring medial joint space width (JSW) of the knee in longitudinal osteoarthritis (OA) trials and to identify the percentage of patients with detectable progression. DESIGN: Retrospective summary of the progression and variability of the change in JSW in knee OA. MATERIAL AND METHODS: Data from the placebo arms of three separate, structure modifying, knee OA trials were compared including gender, age, baseline JSW, change from baseline in JSW, duration of observation, and number and percent of patients with joint space narrowing of various degrees. Computer evaluation of the joint space at its narrowest point in the medial compartment was used in the studies. It is important to note that the narrowest joint space at baseline may not be in the same anatomic location at subsequent evaluations. No statistical tests were performed. RESULTS: The average observation times were 0.98, 0.68 and 0.82 years for the Fluoro, FF, and MTP studies, respectively. The amount of progression was different among the three studies. The Fluoro study showed the greatest magnitude of OA structural progression and the lowest variability. The Fluoro study was expected to show the greatest magnitude of structural progression since it was conducted for the longest duration. For all patients, the standard deviation of the change in JSW was 0.42, 0.63, and 0.53 mm for the Fluoro, FF, and MTP studies, respectively. The percent of patients with detectable progression was similar across studies. CONCLUSION: With these data, information was not sufficient to control for duration of observation and differences in inclusion criteria for the three study populations. Therefore, no definitive conclusions can be made regarding the degree of progression of OA over specific time intervals. However, the data indicate that all three studies contain a cohort of patients that exhibit detectable progression.