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

EULAR recommendations for the use of imaging in the clinical management of peripheral joint osteoarthritis

The increased information provided by modern imaging has led to its more extensive use. Our aim was to develop evidence-based recommendations for the use of imaging in the clinical management of the most common arthropathy, osteoarthritis (OA). A task force (including rheumatologists, radiologists, methodologists, primary care doctors and patients) from nine countries defined 10 questions on the role of imaging in OA to support a systematic literature review (SLR). Joints of interest were the knee, hip, hand and foot; imaging modalities included conventional radiography (CR), MRI, ultrasonography, CT and nuclear medicine. PubMed and EMBASE were searched. The evidence was presented to the task force who subsequently developed the recommendations. The strength of agreement for each recommendation was assessed. 17 011 references were identified from which 390 studies were included in the SLR. Seven recommendations were produced, covering the lack of need for diagnostic imaging in patients with typical symptoms; the role of imaging in differential diagnosis; the lack of benefit in monitoring when no therapeutic modification is related, though consideration is required when unexpected clinical deterioration occurs; CR as the first-choice imaging modality; consideration of how to correctly acquire images and the role of imaging in guiding local injections. Recommendations for future research were also developed based on gaps in evidence, such as the use of imaging in identifying therapeutic targets, and demonstrating the added value of imaging. These evidence-based recommendations and related research agenda provide the basis for sensible use of imaging in routine clinical assessment of people with OA.

Fixed-flexion knee radiography using a new positioning device produced highly repeatable measurements of joint space width: ELSA-Brasil Musculoskeletal Study (ELSA-Brasil MSK)

OBJECTIVE

To describe the performance of a non-fluoroscopic fixed-flexion PA radiographic protocol with a new positioning device, developed for the assessment of knee osteoarthritis (OA) in Brazilian Longitudinal Study of Adult Health Musculoskeletal Study (ELSA-Brasil MSK).

MATERIAL AND METHODS

A test-retest design including 19 adults (38 knee images) was conducted. Feasibility of the radiographic protocol was assessed by image quality parameters and presence of radioanatomic alignment according to intermargin distance (IMD) values. Repeatability was assessed for IMD and joint space width (JSW) measured at three different locations.

RESULTS

Approximately 90% of knee images presented excellent quality. Frequencies of nearly perfect radioanatomic alignment (IMD ≤1mm) ranged from 29% to 50%, and satisfactory alignment was found in up to 71% and 76% of the images (IMD ≤1.5mm and ≤1.7mm, respectively). Repeatability analyses yielded the following results: IMD [SD of mean difference=1.08; coefficient of variation (%CV)=54.68%; intraclass correlation coefficient (ICC) (95%CI)=0.59 (0.34-0.77)]; JSW [SD of mean difference=0.34-0.61; %CV=4.48%-9.80%; ICC (95%CI)=0.74 (0.55-0.85)-0.94 (0.87-0.97)]. Adequately reproducible measurements of IMD and JSW were found in 68% and 87% of the images, respectively.

CONCLUSIONS

Despite the difficulty in achieving consistent radioanatomic alignment between subsequent radiographs in terms of IMD, the protocol produced highly repeatable JSW measurements when these were taken at midpoint and 10mm from the medial extremity of the medial tibial plateau. Therefore, measurements of JSW at these locations can be considered adequate for the assessment of knee OA in ELSA-Brasil MSK.

Baseline and longitudinal change in isometric muscle strength prior to radiographic progression in osteoarthritic and pre-osteoarthritic knees--data from the Osteoarthritis Initiative

OBJECTIVE

To test whether cross-sectional or longitudinal measures of thigh muscle isometric strength differ between knees with and without subsequent radiographic progression of knee osteoarthritis (KOA), with particular focus on pre-osteoarthritic female knees (knees with risk factors but without definite radiographic KOA).

METHODS

Of 4,796 Osteoarthritis Initiative participants, 2,835 knees with Kellgren Lawrence grade (KLG) 0-3 had central X-ray readings, annual quantitative joint space width (JSW) and isometric muscle strength measurements (Good strength chair). Separate slope analysis of covariance (ANCOVA) models were used to determine differences in strength between "progressor" and "non-progressor" knees, after adjusting for age, body mass index, and pain.

RESULTS

466 participant knees exceeded the smallest detectable JSW change during each of two observation intervals (year 2→4 and year 1→3) and were classified as progressors (213 women, 253 men; 128 KLG0/1, 330 KLG2/3); 946 participant knees did not exceed this threshold in either interval and were classified as non-progressors (588 women, 358 from men; 288KLG0/1, 658KLG2/3). Female progressor knees, including those with KLG0/1, tended to have lower extensor and flexor strength at year 2 and at baseline than those without progression, but the difference was not significant after adjusting for confounders. No significant difference was observed in longitudinal change of muscle strength (baseline→year 2) prior to radiographic progression. No significant differences were found for muscle strength in men, and none for change in strength concomitant with progression.

CONCLUSION

This study provides no strong evidence that (changes in) isometric muscle strength precedes or is associated with structural (radiographic) progression of KOA.

Assessment of early tibiofemoral joint space width changes after anterior cruciate ligament injury and reconstruction: a matched case-control study

BACKGROUND

Progression of primary knee osteoarthritis (OA) is often quantified by measuring structural alterations of the joint such as those in tibiofemoral joint space width (JSW) over time. Limited information is available regarding changes that occur during the onset and progression of posttraumatic OA (PTOA) that are often associated with anterior cruciate ligament (ACL) injury. Furthermore, there is a paucity of information regarding JSW changes in healthy patients, making JSW interpretation challenging during early PTOA progression.

PURPOSE

To evaluate tibiofemoral JSW after ACL injury, ACL reconstruction, and rehabilitation compared with healthy, matched controls.

STUDY DESIGN

Cohort study; Level of evidence, 2.

METHODS

A total of 39 ACL-injured patients and 32 matched controls were evaluated. Injured patients were assessed at presurgical baseline and after ACL reconstruction (mean follow-up, 46 months), as were controls. Bilateral, standing, fluoroscopy-assisted, and posterior-anterior metatarsal-phalangeal view knee radiographs were obtained at each visit and JSW was measured.

RESULTS

The JSW differences between knees in control patients were not significantly different and did not change over time. Baseline JSW differences in the ACL group were significantly different than in controls. Three patients (7.9% of total) had an increased JSW difference, and 1 patient (2.6%) had a decreased medial JSW difference. In the lateral compartment, 6 patients (15.8%) had a decreased JSW difference. At follow-up, 2 patients in the ACL group (5%) had a decreased medial JSW difference, and 3 (7.9%) had a significantly increased difference in relation to controls. Lateral compartment analyses revealed 7 (18.4%) patients with a significantly decreased JSW difference and no patients with an increased difference compared with controls.

CONCLUSION

One third of ACL-injured knees underwent significant JSW change soon after injury; consequently, evaluation of within-knee JSW changes over time in ACL-injured patients may not be appropriate with a study based on case-control analysis. The JSWs in the healthy knee of ACL-injured patients do not change over time, allowing this knee to be used as a control for the injured knee. This is important when evaluating the earliest stages of PTOA after ACL injury, when patients are asymptomatic and intervention may be most beneficial.

Direct comparison of fixed flexion, radiography and MRI in knee osteoarthritis: responsiveness data from the Osteoarthritis Initiative

OBJECTIVE

Minimum radiographic joint space width (mJSW) represents the Food and Drug Administration (FDA) standard for demonstrating structural therapeutic benefits for knee osteoarthritis (KOA), but only shows moderate responsiveness (sensitivity to change). We directly compare the responsiveness of magnetic resonance imaging (MRI)-based cartilage thickness and JSW measures from fixed-flexion radiography (FFR) and explore the correlation of region-matched changes between both methods.

METHODS

Nine hundred and sixty-seven knees of Osteoarthritis Initiative participants with radiographic KOA were studied: 445 over 1 year with coronal FLASH MRI and FFR, and 375/522 over 1/2 years with sagittal DESS MRI and FFR. Standardized response means (SRM) of cartilage thickness and mJSW were compared using the sign-test.

RESULTS

With FLASH MRI, SRM was -0.28 for medial femorotibial compartment (MFTC) cartilage loss vs -0.15 for mJSW, and -0.32 vs -0.22 for the most sensitive MRI subregion (central MFTC) vs the most sensitive fixed-location JSW(x = 0.25). With DESS MRI, 1-year SRM was -0.34 for MFTC vs -0.22 for mJSW and -0.44 vs -0.28 for central MFTC vs JSW(x = 0.225). Over 2 years, the SRM was significantly greater for MFTC than for mJSW (-0.43 vs -0.31, P = 0.017) and for central MFTC than for JSW(x = 0.225) (-0.51 vs -0.44, P < 0.001). Correlations between changes in spatially matched MRI subregions and fixed-location JSW were not consistently higher (r = 0.10-0.51) than those between non-matched locations (r = 0.15-0.50).

CONCLUSIONS

MRI displays greater responsiveness in KOA than JSW FFR-based JSW, with the greatest SRM observed in the central medial femorotibial compartment. Fixed-location radiographic measures appear not capable of determining the spatial distribution of femorotibial cartilage loss.

Responsiveness to change and reliability of measurement of radiographic joint space width in osteoarthritis of the knee: a systematic review

OBJECTIVE

The goal of this systematic review was to report the responsiveness to change and reliability of conventional radiographic joint space width (JSW) measurement.

METHOD

We searched the PubMed and Embase databases using the following search criteria: [osteoarthritis (OA) (MeSH)] AND (knee) AND (X-ray OR radiography OR diagnostic imaging OR radiology OR disease progression) AND (joint space OR JSW or disease progression). We assessed responsiveness by calculating the standardized response mean (SRM). We assessed reliability using intra- and inter-reader intra-class correlation (ICC) and coefficient of variation (CV). Random-effects models were used to pool results from multiple studies. Results were stratified by study duration, design, techniques of obtaining radiographs, and measurement method.

RESULTS

We identified 998 articles using the search terms. Of these, 32 articles (43 estimates) reported data on responsiveness of JSW measurement and 24 (50 estimates) articles reported data on measures of reliability. The overall pooled SRM was 0.33 [95% confidence interval (CI): 0.26, 0.41]. Responsiveness of change in JSW measurement was improved substantially in studies of greater than 2 years duration (0.57). Further stratifying this result in studies of greater than 2 years duration, radiographs obtained with the knee in a flexed position yielded an SRM of 0.71. Pooled intra-reader ICC was estimated at 0.97 (95% CI: 0.92, 1.00) and the intra-reader CV estimated at 3.0 (95% CI: 2.0, 4.0). Pooled inter-reader ICC was estimated at 0.93 (95% CI: 0.86, 0.99) and the inter-reader CV estimated at 3.4% (95% CI: 1.3%, 5.5%).

CONCLUSIONS

Measurement of JSW obtained from radiographs in persons with knee is reliable. These data will be useful to clinicians who are planning RCTs where the change in minimum JSW is the outcome of interest.

Quantitative cartilage imaging in knee osteoarthritis

Quantitative measures of cartilage morphology (i.e., thickness) represent potentially powerful surrogate endpoints in osteoarthritis (OA). These can be used to identify risk factors of structural disease progression and can facilitate the clinical efficacy testing of structure modifying drugs in OA. This paper focuses on quantitative imaging of articular cartilage morphology in the knee, and will specifically deal with different cartilage morphology outcome variables and regions of interest, the relative performance and relationship between cartilage morphology measures, reference values for MRI-based knee cartilage morphometry, imaging protocols for measurement of cartilage morphology (including those used in the Osteoarthritis Initiative), sensitivity to change observed in knee OA, spatial patterns of cartilage loss as derived by subregional analysis, comparison of MRI changes with radiographic changes, risk factors of MRI-based cartilage loss in knee OA, the correlation of MRI-based cartilage loss with clinical outcomes, treatment response in knee OA, and future directions of the field.

One-year change in radiographic joint space width in patients with unilateral joint space narrowing: data from the Osteoarthritis Initiative

OBJECTIVE

To examine the rate of joint space width (JSW) loss in both knees of patients with unilateral medial joint space narrowing (JSN) at baseline.

METHODS

Cases were selected from a pool of 2,678 subjects enrolled in the Osteoarthritis Initiative cohort. Inclusion criteria for the present study were unilateral medial JSN, bilateral frequent knee pain, and body mass index (BMI) > or = 25 kg/m(2). Baseline and 1-year fixed flexion radiographs of both knees were read (blinded to time point) using an automated algorithm for minimum JSW and JSW at 4 fixed locations in the medial compartment.

RESULTS

Sixty-seven participants met the inclusion criteria: 43 women and 24 men, with mean +/- SD age 60 +/- 9 years and mean +/- SD BMI 31 +/- 4 kg/m(2). Thirty-seven subjects (55%) had > or = 1 definite tibiofemoral osteophyte. The average progression in no-JSN knees was comparable with that in JSN knees (approximately -0.2 mm/year). However, JSW change was more variable in no-JSN knees, resulting in standardized response means (SRMs; the mean/SD) of approximately -0.24 in no-JSN knees versus approximately -0.41 in JSN knees on average at the 4 fixed locations, and SRMs of -0.24 and -0.35, respectively, for minimum JSW. Young age and high BMI were associated with increased progression, especially in JSN knees.

CONCLUSION

JSN and no-JSN knees progressed at a comparable rate, but a wider distribution of JSW change in no-JSN knees resulted in a poorer sensitivity to change in these knees.

The effect of glucosamine and/or chondroitin sulfate on the progression of knee osteoarthritis: a report from the glucosamine/chondroitin arthritis intervention trial

OBJECTIVE

Osteoarthritis (OA) of the knee causes significant morbidity and current medical treatment is limited to symptom relief, while therapies able to slow structural damage remain elusive. This study was undertaken to evaluate the effect of glucosamine and chondroitin sulfate (CS), alone or in combination, as well as celecoxib and placebo on progressive loss of joint space width (JSW) in patients with knee OA.

METHODS

A 24-month, double-blind, placebo-controlled study, conducted at 9 sites in the United States as part of the Glucosamine/Chondroitin Arthritis Intervention Trial (GAIT), enrolled 572 patients with knee OA who satisfied radiographic criteria (Kellgren/Lawrence [K/L] grade 2 or grade 3 changes and JSW of at least 2 mm at baseline). Patients with primarily lateral compartment narrowing at any time point were excluded. Patients who had been randomized to 1 of the 5 groups in the GAIT continued to receive glucosamine 500 mg 3 times daily, CS 400 mg 3 times daily, the combination of glucosamine and CS, celecoxib 200 mg daily, or placebo over 24 months. The minimum medial tibiofemoral JSW was measured at baseline, 12 months, and 24 months. The primary outcome measure was the mean change in JSW from baseline.

RESULTS

The mean JSW loss at 2 years in knees with OA in the placebo group, adjusted for design and clinical factors, was 0.166 mm. No statistically significant difference in mean JSW loss was observed in any treatment group compared with the placebo group. Treatment effects on K/L grade 2 knees, but not on K/L grade 3 knees, showed a trend toward improvement relative to the placebo group. The power of the study was diminished by the limited sample size, variance of JSW measurement, and a smaller than expected loss in JSW.

CONCLUSION

At 2 years, no treatment achieved a predefined threshold of clinically important difference in JSW loss as compared with placebo. However, knees with K/L grade 2 radiographic OA appeared to have the greatest potential for modification by these treatments.

Joint space narrowing and Kellgren-Lawrence progression in knee osteoarthritis: an analytic literature synthesis

OBJECTIVE

While the interpretation of cartilage findings on magnetic resonance imaging (MRI) evolves, plain radiography remains the standard method for assessing progression of knee osteoarthritis (OA). We sought to describe factors that explain variability in published estimates of radiographic progression in knee OA.

DESIGN

We searched PubMed between January 1985 and October 2006 to identify studies that assessed radiographic progression using either joint space narrowing (JSN) or the Kellgren-Lawrence (K-L) scale. We extracted cohort characteristics [age, gender, and body mass index (BMI)] and technical and other study factors (radiographic approach, study design, OA-related cohort composition). We performed meta-regression analyses of the effects of these variables on both JSN and K-L progression.

RESULTS

Of 239 manuscripts identified, 34 met inclusion criteria. The mean estimated annual JSN rate was 0.13 +/- 0.15 mm/year. While we found no significant association between JSN and radiographic approach among observational studies, full extension was associated with greater estimated JSN among randomized control trials (RCTs). Overall, observational studies that used the semi-flexed approach reported greater JSN than RCTs that used the same approach. The overall mean risk of K-L progression by at least one grade was 5.6 +/- 4.9%, with higher risk associated with shorter study duration, OA definition (K-L > or = 2 vs K-L > or = 1) and cohorts composed of subjects with both incident and prevalent OA.

CONCLUSION

While radiographic approach and study design were associated with JSN, OA definition, cohort composition and study duration were associated with risk of K-L progression. These findings may inform the design of disease modifying osteoarthritis drug (DMOAD) trials and assist clinicians in optimal timing of OA treatments.

The long-term consequence of anterior cruciate ligament and meniscus injuries: osteoarthritis

The objectives of this study are to review the long-term consequences of injuries to the anterior cruciate ligament and menisci, the pathogenic mechanisms, and the causes of the considerable variability in outcome. Injuries of the anterior cruciate ligament and menisci are common in both athletes and the general population. At 10 to 20 years after the diagnosis, on average, 50% of those with a diagnosed anterior cruciate ligament or meniscus tear have osteoarthritis with associated pain and functional impairment: the young patient with an old knee. These individuals make up a substantial proportion of the overall osteoarthritis population. There is a lack of evidence to support a protective role of repair or reconstructive surgery of the anterior cruciate ligament or meniscus against osteoarthritis development. A consistent finding in a review of the literature is the often poor reporting of critical study variables, precluding data pooling or a meta-analysis. Osteoarthritis development in the injured joints is caused by intra-articular pathogenic processes initiated at the time of injury, combined with long-term changes in dynamic joint loading. Variation in outcome is reinforced by additional variables associated with the individual such as age, sex, genetics, obesity, muscle strength, activity, and reinjury. A better understanding of these variables may improve future prevention and treatment strategies. In evaluating medical treatment, we now expect large randomized clinical trials complemented by postmarketing monitoring. We should strive toward a comparable level of quality of evidence in surgical treatment of knee injuries. In instances in which a randomized clinical trial is not feasible, natural history and other observational cohort studies need to be as carefully designed and reported as the classic randomized clinical trial, to yield useful information.

Imaging of knee osteoarthritis: data beyond the beauty

PURPOSE OF REVIEW

MRI has revolutionized osteoarthritis research by providing semi-quantitative and quantitative imaging endpoints on most articular tissues. With the first image data of the Osteoarthritis Initiative now becoming publicly available, this article reviews recent developments in quantitative imaging of osteoarthritis.

RECENT FINDINGS

Although radiography remains the standard for regulatory studies on disease modifying osteoarthritis drugs, there is no consensus on the optimal positioning and acquisition protocol. With MRI, semi-quantitative scoring systems for evaluation of multiple articular tissue changes have been developed and are currently investigated in the context of correlation with symptoms and of predicting structural progression of osteoarthritis. Most efforts on quantitative measurement of imaging endpoints have focused on cartilage morphology and composition, with higher field strength (3T), newer sequences, and new measurement endpoints being a driver of current innovation.

SUMMARY

The semi-quantitative and quantitative tools for analysis of articular structure are now available and permit comprehensive analysis of morphological and compositional tissue changes in osteoarthritis. These changes will need to be related to clinical outcomes (e.g. how a patient feels or functions) with current epidemiological studies, such as the Osteoarthritis Initiatives, providing the opportunity for clinical validation of these imaging biomarkers.