Interobserver Agreement and Performance of Concurrent AI Assistance for Radiographic Evaluation of Knee Osteoarthritis.

Background Due to conflicting findings in the literature, there are concerns about a lack of objectivity in grading knee osteoarthritis (KOA) on radiographs. Purpose To examine how artificial intelligence (AI) assistance affects the performance and interobserver agreement of radiologists and orthopedists of various experience levels when evaluating KOA on radiographs according to the established Kellgren-Lawrence (KL) grading system. Materials and Methods In this retrospective observer performance study, consecutive standing knee radiographs from patients with suspected KOA were collected from three participating European centers between April 2019 and May 2022. Each center recruited four readers across radiology and orthopedic surgery at in-training and board-certified experience levels. KL grading (KL-0 = no KOA, KL-4 = severe KOA) on the frontal view was assessed by readers with and without assistance from a commercial AI tool. The majority vote of three musculoskeletal radiology consultants established the reference standard. The ordinal receiver operating characteristic method was used to estimate grading performance. Light kappa was used to estimate interrater agreement, and bootstrapped t statistics were used to compare groups. Results Seventy-five studies were included from each center, totaling 225 studies (mean patient age, 55 years ± 15 [SD]; 113 female patients). The KL grades were KL-0, 24.0% (n = 54); KL-1, 28.0% (n = 63); KL-2, 21.8% (n = 49); KL-3, 18.7% (n = 42); and KL-4, 7.6% (n = 17). Eleven readers completed their readings. Three of the six junior readers showed higher KL grading performance with versus without AI assistance (area under the receiver operating characteristic curve, 0.81 ± 0.017 [SEM] vs 0.88 ± 0.011 [P < .001]; 0.76 ± 0.018 vs 0.86 ± 0.013 [P < .001]; and 0.89 ± 0.011 vs 0.91 ± 0.009 [P = .008]). Interobserver agreement for KL grading among all readers was higher with versus without AI assistance (κ = 0.77 ± 0.018 [SEM] vs 0.85 ± 0.013; P < .001). Board-certified radiologists achieved almost perfect agreement for KL grading when assisted by AI (κ = 0.90 ± 0.01), which was higher than that achieved by the reference readers independently (κ = 0.84 ± 0.017; P = .01). Conclusion AI assistance increased junior readers' radiographic KOA grading performance and increased interobserver agreement for osteoarthritis grading across all readers and experience levels. Published under a CC BY 4.0 license. Supplemental material is available for this article.

Constructing a clinical radiographic knee osteoarthritis database using artificial intelligence tools with limited human labor: A proof of principle.

OBJECTIVE: To create a scalable and feasible retrospective consecutive knee osteoarthritis (OA) radiographic database with limited human labor using commercial and custom-built artificial intelligence (AI) tools. METHODS: We applied four AI tools, two commercially available and two custom-built tools, to analyze 6 years of clinical consecutive knee radiographs from patients aged 35-79 at the University of Copenhagen Hospital, Bispebjerg-Frederiksberg Hospital, Denmark. The tools provided Kellgren-Lawrence (KL) grades, joint space widths, patella osteophyte detection, radiographic view detection, knee joint implant detection, and radiographic marker detection. RESULTS: In total, 25,778 knee radiographs from 8575 patients were included in the database after excluding inapplicable radiographs, and 92.5% of the knees had a complete OA dataset. Using the four AI tools, we saved about 800 hours of radiologist reading time and only manually reviewed 16.0% of the images in the database. CONCLUSIONS: This study shows that clinical knee OA databases can be built using AI with limited human reading time for uniform grading and measurements. The concept is scalable temporally and across geographic regions and could help diversify further OA research by efficiently including radiographic knee OA data from different populations globally. We can prevent data dredging and overfitting OA theories on existing trite cohorts by including various gene pools and continuous expansion of new clinical cohorts. Furthermore, the suggested tools and applied approaches provide an ability to retest previous hypotheses and test new hypotheses on real-life clinical data with current disease prevalence and trends.

Standardized reporting of spine and sacroiliac joints in axial spondyloarthritis MRI: from the ESSR-Arthritis Subcommittee.

OBJECTIVES: Apply a modified Delphi-based approach and produce a practical, radiology-specific set of definitions for interpretation and standardization of the multiple MRI findings in axial spondyloarthritis (ax-SpA), specifically to aid the general radiologist with a musculoskeletal interest, working with gold standard basic MRI protocols. MATERIALS AND METHODS: We report the results of a modified Delphi-based consensus of 35 experts from 13 countries in the Arthritis Subcommittee of the European Society of Musculoskeletal Radiology (ESSR). Seventeen definitions were created (i.e., nine for the spine and eight for the sacroiliac joint) and two Delphi rounds were conducted on an electronic database, collated and revised by the project leader with agreement. Group leads were appointed for each definition following the first round. Final definitions included only those that reached a consensus > 80%; if > 50% agreed on exclusion consensus, definitions were excluded. Final results have been shared during the Arthritis meeting at the Annual ESSR Congress. RESULTS: Fourteen definitions, eight for the spine and six for the sacroiliac joint were agreed for standardized reporting. Andersson's, anterior corner sclerotic and costovertebral joint inflammatory lesions of the spine, with active and non-active erosions, and fat metaplasia of the sacroiliac joint reaching the highest consensus (≥ 95%). More than 50% of the experts agreed to exclude joint space inflammation in the sacroiliac joint and tissue backfill. Syndesmophytes reached 76% agreement. CONCLUSIONS: Agreed definitions by expert radiologists using a modified Delphi process, should allow standardized actionable radiology reports and clarity in reporting terminology of ax-SpA. CLINICAL RELEVANCE STATEMENT: The proposed definitions will support reporting from musculoskeletal and general radiologists working with gold-standard basic MRI, improve confidence in lesion assessment, and standardize terminology to provide actionable reports on MRI in patients with ax-SpA. KEY POINTS: Experts applied a modified Delphi method to optimize the definitions of MRI findings of ax-SpA. After two Delphi rounds and one in-person meeting, fourteen definitions reached the agreement threshold. These consensus-based definitions will aid in actionable reporting specifically for the general radiologist with a musculoskeletal interest.

Effect of repeated prolonged exercise on liver fat content and visceral adipose tissue in well-trained older men.

INTRODUCTION: Liver fat (LF) and visceral adipose tissue (VAT) content decreases with training, however, this has mainly been investigated in sedentary obese or healthy participants. The aim of this study was to investigate the effects of repeated prolonged exercise on LF and VAT content in well-trained older men and to compare baseline LF and VAT content to recreationally active older men. METHOD: A group of five well-trained older men were tested before and after cycling a total distance of 2558 km in 16 consecutive days. VAT content and body composition was measured using DXA before a bicycle ergometer test was performed to determine maximal fat oxidation (MFO), maximal oxygen consumption ( VO 2 max $$ {\mathrm{VO}}_{2_{\mathrm{max}}} $$ ), and the relative intensity at which MFO occurred (Fatmax). LF content was measured on a separate day using MRI. For comparison of baseline values, a control group of eight healthy age- and BMI-matched recreationally active men were recruited. RESULTS: The well-trained older men had lower VAT (p = 0.02), and a tendency toward lower LF content (p = 0.06) compared with the control group. The intervention resulted in decreased LF content (p = 0.02), but VAT, fat mass, and lean mass remained unchanged. VO 2 max $$ {\mathrm{VO}}_{2_{\mathrm{max}}} $$ , MFO, and Fatmax were not affected by the intervention. CONCLUSION: The study found that repeated prolonged exercise reduced LF content, but VAT and VO 2 max $$ {\mathrm{VO}}_{2_{\mathrm{max}}} $$ remained unchanged. Aerobic capacity was aligned with lower LF and VAT in older active men.

CT in musculoskeletal imaging: still helpful and for what?

Computed tomography (CT) is a common modality employed for musculoskeletal imaging. Conventional CT techniques are useful for the assessment of trauma in detection, characterization and surgical planning of complex fractures. CT arthrography can depict internal derangement lesions and impact medical decision making of orthopedic providers. In oncology, CT can have a role in the characterization of bone tumors and may elucidate soft tissue mineralization patterns. Several advances in CT technology have led to a variety of acquisition techniques with distinct clinical applications. These include four-dimensional CT, which allows examination of joints during motion; cone-beam CT, which allows examination during physiological weight-bearing conditions; dual-energy CT, which allows material decomposition useful in musculoskeletal deposition disorders (e.g., gout) and bone marrow edema detection; and photon-counting CT, which provides increased spatial resolution, decreased radiation, and material decomposition compared to standard multi-detector CT systems due to its ability to directly translate X-ray photon energies into electrical signals. Advanced acquisition techniques provide higher spatial resolution scans capable of enhanced bony microarchitecture and bone mineral density assessment. Together, these CT acquisition techniques will continue to play a substantial role in the practices of orthopedics, rheumatology, metabolic bone, oncology, and interventional radiology.

Autonomous Chest Radiograph Reporting Using AI: Estimation of Clinical Impact.

Background Automated interpretation of normal chest radiographs could alleviate the workload of radiologists. However, the performance of such an artificial intelligence (AI) tool compared with clinical radiology reports has not been established. Purpose To perform an external evaluation of a commercially available AI tool for (a) the number of chest radiographs autonomously reported, (b) the sensitivity for AI detection of abnormal chest radiographs, and (c) the performance of AI compared with that of the clinical radiology reports. Materials and Methods In this retrospective study, consecutive posteroanterior chest radiographs from adult patients in four hospitals in the capital region of Denmark were obtained in January 2020, including images from emergency department patients, in-hospital patients, and outpatients. Three thoracic radiologists labeled chest radiographs in a reference standard based on chest radiograph findings into the following categories: critical, other remarkable, unremarkable, or normal (no abnormalities). AI classified chest radiographs as high confidence normal (normal) or not high confidence normal (abnormal). Results A total of 1529 patients were included for analysis (median age, 69 years [IQR, 55-69 years]; 776 women), with 1100 (72%) classified by the reference standard as having abnormal radiographs, 617 (40%) as having critical abnormal radiographs, and 429 (28%) as having normal radiographs. For comparison, clinical radiology reports were classified based on the text and insufficient reports excluded (n = 22). The sensitivity of AI was 99.1% (95% CI: 98.3, 99.6; 1090 of 1100 patients) for abnormal radiographs and 99.8% (95% CI: 99.1, 99.9; 616 of 617 patients) for critical radiographs. Corresponding sensitivities for radiologist reports were 72.3% (95% CI: 69.5, 74.9; 779 of 1078 patients) and 93.5% (95% CI: 91.2, 95.3; 558 of 597 patients), respectively. Specificity of AI, and hence the potential autonomous reporting rate, was 28.0% of all normal posteroanterior chest radiographs (95% CI: 23.8, 32.5; 120 of 429 patients), or 7.8% (120 of 1529 patients) of all posteroanterior chest radiographs. Conclusion Of all normal posteroanterior chest radiographs, 28% were autonomously reported by AI with a sensitivity for any abnormalities higher than 99%. This corresponded to 7.8% of the entire posteroanterior chest radiograph production. © RSNA, 2023 Supplemental material is available for this article. See also the editorial by Park in this issue.

Commercially Available Chest Radiograph AI Tools for Detecting Airspace Disease, Pneumothorax, and Pleural Effusion.

Background Commercially available artificial intelligence (AI) tools can assist radiologists in interpreting chest radiographs, but their real-life diagnostic accuracy remains unclear. Purpose To evaluate the diagnostic accuracy of four commercially available AI tools for detection of airspace disease, pneumothorax, and pleural effusion on chest radiographs. Materials and Methods This retrospective study included consecutive adult patients who underwent chest radiography at one of four Danish hospitals in January 2020. Two thoracic radiologists (or three, in cases of disagreement) who had access to all previous and future imaging labeled chest radiographs independently for the reference standard. Area under the receiver operating characteristic curve, sensitivity, and specificity were calculated. Sensitivity and specificity were additionally stratified according to the severity of findings, number of findings on chest radiographs, and radiographic projection. The χ2 and McNemar tests were used for comparisons. Results The data set comprised 2040 patients (median age, 72 years [IQR, 58-81 years]; 1033 female), of whom 669 (32.8%) had target findings. The AI tools demonstrated areas under the receiver operating characteristic curve ranging 0.83-0.88 for airspace disease, 0.89-0.97 for pneumothorax, and 0.94-0.97 for pleural effusion. Sensitivities ranged 72%-91% for airspace disease, 63%-90% for pneumothorax, and 62%-95% for pleural effusion. Negative predictive values ranged 92%-100% for all target findings. In airspace disease, pneumothorax, and pleural effusion, specificity was high for chest radiographs with normal or single findings (range, 85%-96%, 99%-100%, and 95%-100%, respectively) and markedly lower for chest radiographs with four or more findings (range, 27%-69%, 96%-99%, 65%-92%, respectively) (P < .001). AI sensitivity was lower for vague airspace disease (range, 33%-61%) and small pneumothorax or pleural effusion (range, 9%-94%) compared with larger findings (range, 81%-100%; P value range, > .99 to < .001). Conclusion Current-generation AI tools showed moderate to high sensitivity for detecting airspace disease, pneumothorax, and pleural effusion on chest radiographs. However, they produced more false-positive findings than radiology reports, and their performance decreased for smaller-sized target findings and when multiple findings were present. © RSNA, 2023 Supplemental material is available for this article. See also the editorial by Yanagawa and Tomiyama in this issue.

Genome-wide association meta-analysis of knee and hip osteoarthritis uncovers genetic differences between patients treated with joint replacement and patients without joint replacement.

OBJECTIVES: Osteoarthritis is a common and severe, multifactorial disease with a well-established genetic component. However, little is known about how genetics affect disease progression, and thereby the need for joint placement. Therefore, we aimed to investigate whether the genetic associations of knee and hip osteoarthritis differ between patients treated with joint replacement and patients without joint replacement. METHODS: We included knee and hip osteoarthritis cases along with healthy controls, altogether counting >700 000 individuals. The cases were divided into two groups based on joint replacement status (surgical vs non-surgical) and included in four genome-wide association meta-analyses: surgical knee osteoarthritis (N = 22 525), non-surgical knee osteoarthritis (N = 38 626), surgical hip osteoarthritis (N = 20 221) and non-surgical hip osteoarthritis (N = 17 847). In addition, we tested for genetic correlation between the osteoarthritis groups and the pain phenotypes intervertebral disc disorder, dorsalgia, fibromyalgia, migraine and joint pain. RESULTS: We identified 52 sequence variants associated with knee osteoarthritis (surgical: 17, non-surgical: 3) or hip osteoarthritis (surgical: 34, non-surgical: 1). For the surgical phenotypes, we identified 10 novel variants, including genes involved in autophagy (rs2447606 in ATG7) and mechanotransduction (rs202127176 in PIEZO1). One variant, rs13107325 in SLC39A8, associated more strongly with non-surgical knee osteoarthritis than surgical knee osteoarthritis. For all other variants, significance and effect sizes were higher for the surgical phenotypes. In contrast, genetic correlations with pain phenotypes tended to be stronger in the non-surgical groups. CONCLUSIONS: Our results indicate differences in genetic associations between knee and hip osteoarthritis depending on joint replacement status.

Current Role of Conventional Radiography of Sacroiliac Joints in Adults and Juveniles with Suspected Axial Spondyloarthritis: Opinion from the ESSR Arthritis and Pediatric Subcommittees.

This opinion article by the European Society of Musculoskeletal Radiology Arthritis and Pediatric Subcommittees discusses the current use of conventional radiography (CR) of the sacroiliac joints in adults and juveniles with suspected axial spondyloarthritis (axSpA). The strengths and limitations of CR compared with magnetic resonance imaging (MRI) and computed tomography (CT) are presented.Based on the current literature and expert opinions, the subcommittees recognize the superior sensitivity of MRI to detect early sacroiliitis. In adults, supplementary pelvic radiography, low-dose CT, or synthetic CT may be needed to evaluate differential diagnoses. CR remains the method of choice to detect structural changes in patients with suspected late-stage axSpA or established disease and in patients with suspected concomitant hip or pubic symphysis involvement. In children, MRI is the imaging modality of choice because it can detect active as well as structural changes and is radiation free.

Comparison between conventional MRI and weight-bearing positional MRI reveals important differences in radiological measurements of the patellofemoral joint.

OBJECTIVE: To compare radiological measurements of the patellofemoral joint (PFJ) morphology and measurement reproducibility across the following scanning modalities: (a) 3 T supine MRI, (b) 0.25 T supine MRI and (c) standing 0.25 T MRI. METHODS: Forty patients referred to MRI of the knee were scanned by high field 3 T MRI in supine position and low field 0.25 T positional (pMRI) in supine and standing positions. Radiological measurements for assessment of femoral trochlear morphology, patellar tracking, patellar height and knee flexion angle were compared across scanning situations by one-way repeated-measures ANOVA. Measurement reliability and agreement were assessed by calculation of ICC, SEM and MDC. RESULTS: Patellar tracking differed across scanning situations, particularly between 3.0 T supine and 0.25 T standing position. Mean differences are the following: patella bisect offset (PBO): 9.6%, p ≤ 0.001; patellar tilt angle (PTA): 3.1°, p ≤ 0.001; tibial tuberosity-trochlear groove distance (TT-TG): 2.7 mm, p ≤ 0.001). Measurements revealed slight knee joint flexion in supine and slight hyperextension in the standing position (MD: 9.3°, P ≤ 0.001), likely related to the observed differences in patellar tracking. Reproducibility was comparable across MRI field strengths. In general, PBO, PTA and TT-TG were the most robust measurements in terms of reproducibility and agreement across scanning situations (ICC range: 0.85-0.94). CONCLUSION: Significant differences in important patellofemoral morphology measurements were observed between supine and standing MRI scanning positions. These were unlikely due to physiological factors such as changes in joint loading but rather induced by slight differences in knee flexion angle. This emphasises the need to standardise knee positioning during scanning, particularly for weight-bearing positional MRI before clinical use.

Weight-bearing cone-beam CT: the need for standardised acquisition protocols and measurements to fulfill high expectations-a review of the literature.

Weight bearing CT (WBCT) of the lower extremity is gaining momentum in evaluation of the foot/ankle and knee. A growing number of international studies use WBCT, which is promising for improving our understanding of anatomy and biomechanics during natural loading of the lower extremity. However, we believe there is risk of excessive enthusiasm for WBCT leading to premature application of the technique, before sufficiently robust protocols are in place e.g. standardised limb positioning and imaging planes, choice of anatomical landmarks and image slices used for individual measurements. Lack of standardisation could limit benefits from introducing WBCT in research and clinical practice because useful imaging information could become obscured. Measurements of bones and joints on WBCT are influenced by joint positioning and magnitude of loading, factors that need to be considered within a 3-D coordinate system. A proportion of WBCT studies examine inter- and intraobserver reproducibility for different radiological measurements in the knee or foot with reproducibility generally reported to be high. However, investigations of test-retest reproducibility are still lacking. Thus, the current ability to evaluate, e.g. the effects of surgery or structural disease progression, is questionable. This paper presents an overview of the relevant literature on WBCT in the lower extremity with an emphasis on factors that may affect measurement reproducibility in the foot/ankle and knee. We discuss the caveats of performing WBCT without consensus on imaging procedures and measurements.

Two-year MRI-defined structural damage and patient-reported outcomes following surgery or exercise for meniscal tears in young adults.

OBJECTIVE: To investigate potential differences in structural knee joint damage assessed by MRI and patient-reported outcomes (PROMs) at 2-year follow-up between young adults randomised to early surgery or exercise and education with optional delayed surgery for a meniscal tear. METHODS: A secondary analysis of a multicentre randomised controlled trial including 121 patients (18-40 years) with an MRI-verified meniscal tear. For this study, only patients with 2-year follow-up were included. The main outcomes were the difference in worsening of structural knee damage, assessed by MRI using the Anterior Cruciate Ligament OsteoArthrits Score, and the difference in change in the mean score of four Knee Injury and Osteoarthritis Outcome Score (KOOS4) subscales covering pain, symptoms, function in sport and recreation, and quality of life, from baseline to 2 years. RESULTS: In total, 82/121 (68%) patients completed the 2-year follow-up (39 from the surgical group and 43 from the exercise group). MRI-defined cartilage damage had developed or progressed in seven (9.1%) patients and osteophytes developed in two (2.6%) patients. The worsening of structural damage from baseline to 2-year follow-up was similar between groups. The mean (95% CI) adjusted differences in change in KOOS4 between intervention groups from baseline to 2 years was -1.4 (-9.1, 6.2) points. The mean improvement in KOOS4 was 16.4 (10.4, 22.4) in the surgical group and 21.5 (15.0, 28.0) in the exercise group. No between group differences in improvement were found in the KOOS subscales. CONCLUSIONS: The 2-year worsening of MRI-defined structural damage was limited and similar in young adult patients with a meniscal tear treated with surgery or exercise with optional delayed surgery. Both groups had similar clinically relevant improvements in KOOS4, suggesting the choice of treatment strategy does not impact 2-year structural knee damage or PROMs. TRIAL REGISTRATION NUMBER: NCT02995551.

Tapering of TNF inhibitors in axial spondyloarthritis in routine care - 2-year clinical and MRI outcomes and predictors of successful tapering.

OBJECTIVES: In a 2-year follow-up study of patients with axial spondyloarthritis (axSpA) in clinical remission who tapered TNF inhibitor (TNFi) treatment according to a clinical guideline, we aimed to investigate the proportion who successfully tapered/discontinued therapy and baseline predictors thereof. The proportion regaining clinical remission after flare and the progression on MRI/radiography were also assessed. METHODS: One-hundred-and-nine patients (78 [72%]/31 [28%] receiving standard and reduced dose, respectively) in clinical remission (BASDAI < 40, physician global score < 40) and no signs of disease activity the previous year tapered TNFi as follows: to two-thirds of standard dose at baseline, half at week 16, one-third at week 32 and discontinuation at week 48. Patients experiencing clinical, BASDAI or MRI flare (predefined criteria) stopped tapering and escalated to previous dose. Prediction analyses were performed by multivariable regression. RESULTS: One hundred and six patients (97%) completed 2 years' follow-up; 55 patients (52%) had successfully tapered: 23 (22%) receiving two-thirds, 15 (14%) half, 16 (15%) one-third dose and 1 (1%) discontinued. In patients at standard dose at baseline (n = 78), lower physician global score was the only independent predictor of successful tapering (odds ratio [OR] = 0.79 [95% CI: 0.64, 0.93]; P = 0.003). In the entire patient group lower physician global score (OR = 0.86 [0.75, 0.98]; P = 0.017), lower Spondyloarthritis Research Consortium of Canada (SPARCC) Sacroiliac Joint Erosion score (OR = 0.78 [0.57, 0.98]; P = 0.029) and current smoker (OR = 3.28 [1.15, 10.57]; P = 0.026) were independent predictors of successful tapering. At 2 years, 97% of patients were in clinical remission. Minimal changes in imaging findings were observed. CONCLUSION: After 2 years following a clinical guideline, 52% of patients with axSpA in clinical remission had successfully tapered TNFi, only 1% discontinued. Baseline physician global score was an independent predictor of successful tapering.

Intra-articular therapies: patient preferences and professional practices in European countries.

To assess patient perspective and professional practice of intraarticular therapies (IATs) across Europe, an expert international multidisciplinary panel designed two open web-based surveys: one targeting people who had experienced at least two IATs (44 items); and one targeting health care providers (HCPs) (160 items). Surveys were disseminated via patient and professional associations and social media. A descriptive analysis was performed. The surveys were answered by 200 patients and 186 HCPs from 26 countries, showing that IAT is routinely performed by rheumatologists (97%) and orthopaedic surgeons (89%), with specific training being compulsory in a few countries. The most frequent indications for IAT are arthritis (76%), osteoarthritis (74%), crystal arthritis (71%) and bursitis (70%); the most frequently injected joints are knee (78%) and shoulder (70%); and the most used compounds are glucocorticoids. The majority of HCPs report informing patients about side-effects (73%), benefits (72%), and the nature of the procedure (72%), which coincides with 27% of patients reporting that they had not been informed about benefits or potential complications of IATs; 73% of patients had not been asked whether they wanted an anaesthetic. Few HCPs (10%) obtain written consent (56% get oral consent, being mandatory for 32%), a procedure deemed necessary by 41% of the patients. 50% of patients reported a clear benefit of IAT and 20% experienced complications including pain, impaired mobility, rashes, or swelling. In summary, the practice of IAT is variable across Europe, and although patients perceive it as relatively safe and usually effective procedure, some gaps were identified.

Do Ahlbäck scores identify subgroups with different magnitudes of cartilage thickness loss in patients with moderate to severe radiographic osteoarthritis? One-year follow-up data from the Osteoarthritis Initiative.

OBJECTIVE: Kellgren-Lawrence grades (KLG) are frequently used for patient selection in clinical trials. The Ahlbäck radiographic grading system has been developed for moderate and severe knee OA. KLG 3 is comparable to Ahlbäck 1 and KLG 4 is subdivided into Ahlbäck 2-5. The objective of this study was to investigate if the Ahlbäck scoring system is able to subdivide patients with moderate to severe knee OA (KLG 3/4) into groups with different sensitivity to change in cartilage thickness. MATERIALS AND METHODS: This study was based on 108 Osteoarthritis Initiative (OAI) participants with KLG 3/4. Baseline KLG scores were available from the OAI database; Ahlbäck scores were performed using the same x-rays. Cartilage thickness change in the weight-bearing femorotibial cartilage was analysed from baseline and year 1 3D FLASH MRI for the entire femorotibial joint (FTJ), the medial (MFTC) and the lateral compartment (LFTC) and for the location-independent ordered values 1 and 16 (OV 1/OV 16) representing the subregions with largest loss (OV 1) and gain (OV 16) within each knee. RESULTS: Of the 108 patients, n = 30/78 had KLG 3/4. The corresponding Ahlbäck scores (1-5) were n = 30/33/36/9/10. Cartilage thickness changes between Ahlbäck groups showed no statistically significant difference for FTJ, MFTC, LFTC and OV 1, but change in OV 16 was significantly higher in Ahlbäck 4 knees (p = 0.03) compared to Ahlbäck 1-3 knees. CONCLUSION: Radiographic knee OA grading with Ahlbäck scores was not superior to KLG for prediction of cartilage thickness loss over 1 year, in patients with moderate and severe knee OA supporting the continuous use of the easier and more widely used KLG.

EULAR recommendations for intra-articular therapies.

OBJECTIVES: To establish evidence-based recommendations to guide health professionals using intra-articular therapies (IAT) in adult patients with peripheral arthropathies. METHODS: A multidisciplinary international task force established the objectives, users and scope and the need for background information, including systematic literature reviews) and two surveys addressed to healthcare providers and patients throughout Europe. The evidence was discussed in a face-to-face meeting, recommendations were formulated and subsequently voted for anonymously in a three-round Delphi process to obtain the final agreement. The level of evidence was assigned to each recommendation with the Oxford levels of evidence. RESULTS: Recommendations focus on practical aspects to guide health professionals before, during and after IAT in adult patients with peripheral arthropathies. Five overarching principles and 11 recommendations were established, addressing issues related to patient information, procedure and setting, accuracy, routine and special aseptic care, safety issues and precautions to be addressed in special populations, efficacy and safety of repeated joint injections, use of local anaesthetics and aftercare. CONCLUSION: We have developed the first evidence and expert opinion-based recommendations to guide health professionals using IAT. We hope that these recommendations will be included in different educational programmes, used by patient associations and put into practice via scientific societies to help improve uniformity and quality of care when performing IAT in peripheral adult joints.

Doppler ultrasound predicts successful discontinuation of biological DMARDs in rheumatoid arthritis patients in clinical remission.

OBJECTIVE: To assess the ability of ultrasound to predict successful tapering and successful discontinuation of biological DMARDs (bDMARDs) at the 2-year follow-up in RA patients in sustained remission. METHODS: Patients in sustained remission (DAS28-CRP ≤ 2.6) and with no radiographic progression the previous year tapered bDMARDs according to a standardized regime. A total of 119 of these patients were included in this ultrasound substudy. At baseline, clinical assessment, MRI, X-ray and ultrasound of 24 joints were performed. Ultrasound-detected synovitis was defined and scored 0-3 using the OMERACT scoring system at the joint level for both grey-scale and Doppler activity. Sum scores for each ultrasound modality were calculated for 24 joints at the patient level. The final state of treatment was assessed after 2 years. The predictive value of ultrasound measures for successful tapering and discontinuation at the 2-year follow-up was assessed via logistic regression analyses. RESULTS: Negative IgM-RF [odds ratio (OR) = 0.29, 95% CI: 0.10-0.85; P = 0.024] and lower Doppler sum score of 24 joints (OR = 0.44, 95% CI: 0.15, 0.87; P = 0.014) were independent predictors for successful discontinuation of bDMARDs at the 2-year follow-up. The predictive value of the Doppler sum score was independent of MRI findings. Previous numbers of bDMARDs were predictive of successful tapering (OR = 0.58, 95% CI: 0.35, 0.91; P = 0.018), whereas ultrasound was not. Clinical parameters were not predictive of successful tapering/discontinuation. CONCLUSION: Doppler sum score was an independent predictor for successful discontinuation of bDMARDs at the 2-year follow-up-the odds for achieving successful discontinuation decreased by 56% per one-unit increase in Doppler sum score. Ultrasound could not predict successful tapering.

Predictors of joint damage progression and stringent remission in patients with established rheumatoid arthritis in clinical remission.

OBJECTIVES: To study if clinical, radiographic and MRI markers can predict MRI and radiographic damage progression and achievement of stringent remission in patients with established RA in clinical remission followed by a targeted treatment strategy. METHODS: RA patients (DAS28-CRP <3.2, no swollen joints) receiving conventional synthetic DMARDs were randomized to conventional or MRI-targeted treat-to-target strategies with predefined algorithmic treatment escalations. Potentially predictive baseline variables were tested in multivariate logistic regression analyses. RESULTS: In the 171 patients included, baseline MRI osteitis independently predicted progression in MRI erosion [odds ratio (OR) 1.13 (95% CI 1.06, 1.22)], joint space narrowing [OR 1.15 (95% CI 1.07, 1.24)] and combined damage [OR 1.23 (95% CI 1.13, 1.37)], while tenosynovitis independently predicted MRI erosion progression [OR 1.13 (95% CI 1.03, 1.25)]. A predictor of radiographic erosion progression was age, while gender predicted progression in joint space narrowing. Following an MRI treat-to-target strategy predicted stringent remission across all remission definitions: Clinical Disease Activity Index remission OR 2.94 (95% CI 1.25, 7.52), Simplified Disease Activity Index remission OR 2.50 (95% CI 1.01, 6.66), ACR/EULAR Boolean remission OR 5.47 (95% CI 2.33, 14.13). Similarly, low tender joint count and low patient visual analogue scale pain and global independently predicted achievement of more stringent remission. CONCLUSION: Baseline MRI osteitis and tenosynovitis were independent predictors of 2 year MRI damage progression in RA patients in clinical remission, while independent predictors of radiographic damage progression were age and gender. Following an MRI treat-to-target strategy, low scores of patient-reported outcomes and low tender joint count predicted achievement of stringent remission. TRIAL REGISTRATION: ClinicalTrials.gov (https://clinicaltrials.gov), NCT01656278.

Early development of tendinopathy in humans: Sequence of pathological changes in structure and tissue turnover signaling.

Overloading of tendon tissue with resulting chronic pain (tendinopathy) is a common disorder in occupational-, leisure- and sports-activity, but its pathogenesis remains poorly understood. To investigate the very early phase of tendinopathy, Achilles and patellar tendons were investigated in 200 physically active patients and 50 healthy control persons. Patients were divided into three groups: symptoms for 0-1 months (T1), 1-2 months (T2) or 2-3 months (T3). Tendinopathic Achilles tendon cross-sectional area determined by ultrasonography (US) was ~25% larger than in healthy control persons. Both Achilles and patellar anterior-posterior diameter were elevated in tendinopathy, and only later in Achilles was the width increased. Increased tendon size was accompanied by an increase in hypervascularization (US Doppler flow) without any change in mRNA for angiogenic factors. From patellar biopsies taken bilaterally, mRNA for most growth factors and tendon components remained unchanged (except for TGF-beta1 and substance-P) in early tendinopathy. Tendon stiffness remained unaltered over the first three months of tendinopathy and was similar to the asymptomatic contra-lateral tendon. In conclusion, this suggests that tendinopathy pathogenesis represents a disturbed tissue homeostasis with fluid accumulation. The disturbance is likely induced by repeated mechanical overloading rather than a partial rupture of the tendon.

Positional changes in lumbar disc herniation during standing or lumbar extension: a cross-sectional weight-bearing MRI study.

OBJECTIVES: To investigate biomechanical changes in lumbar disc herniations. METHODS: Patients with lumbar disc herniation verified on a 1.5-3-T magnetic resonance imaging (MRI) scanner were imaged in a weight-bearing 0.25-T MRI scanner in (1) standing position, (2) conventional supine position with relative lumbar flexion, and (3) supine position with a forced lumbar extension by adding a lumbar pillow. The L2-S1 lordosis angle, the disc cross-sectional area, the disc cross-sectional diameter, and the spinal canal cross-sectional diameter were measured for each position. Disc degeneration and nerve root compression were graded, and the pain intensity was reported during each scan position. RESULTS: Forty-three herniated discs in 37 patients (36.7 ± 11.9 years) were analyzed in each position. The L2-S1 lumbar angle increased in the standing position (mean difference [MD]: 5.61°, 95% confidence interval [95% CI]: 3.44 to 7.78) and with the lumbar pillow in the supine position (MD: 14.63°, 95% CI: 11.71 to 17.57), both compared with the conventional supine position. The herniated disc cross-sectional area and diameter increased during standing compared with during conventional supine position. No changes were found in the spinal canal cross-sectional diameter between positions. Higher nerve root compression grades for paracentral herniations were found during standing compared with during conventional supine position. This was neither found with a lumbar pillow nor for central herniations in any position compared with conventional supine. CONCLUSION: Disc herniations displayed dynamic behavior with morphological changes in the standing position, leading to higher nerve root compression grades for paracentral herniated discs. KEY POINTS: • Lumbar herniated discs increased in size in the axial plane during standing. • Increased nerve root compression grades for paracentral herniated discs were found during standing. • Weight-bearing MRI may increase the diagnostic sensitivity of nerve root compression in lumbar disc herniations.