Ultrasound imaging in crystal arthropathies: a pictorial review

OBJECTIVE

The prevalence of crystal arthropathies in the general population is rising. The purpose of this pictorial study is to describe the sonographic elements of the most prevalent crystal arthropathies by emphasizing particular sonographic findings using illustrative images and cases while considering technical details and common pitfalls.

METHODS

Using established recommendations, specialists in the fields of sonography and crystal arthropathies agreed by consensus on the unique ultrasound signs associated with each of the conditions.

RESULTS

Gout, calcium pyrophosphate deposition arthropathy, and hydroxyapatite arthropathy are the three most prevalent crystal arthropathies. Today's high-resolution sonography enables reliable evaluation of the underlying crystal deposits, post-inflammatory changes, and a precise description of joint inflammation.

CONCLUSIONS

High-prevalence crystal arthropathies are reliably detectable by ultrasound with current ultrasound equipment. It is necessary to have extensive ultrasound training, know specific sonographic findings, and understand all possible differential diagnoses for disorders affecting the musculoskeletal system.

POS0132 THE FIRST ALGORITHM TO INTEGRATE ULTRASONOGRAPHY IN THE DIAGNOSTIC PROCESS OF DIFFERENTIAL DIAGNOSIS OF INFLAMMATORY ARTHROPATHY IN CLINICAL PRACTICE: A STUDY FROM THE MSUS WORKING GROUP OF THE ITALIAN SOCIETY OF RHEUMATOLOGY

Background

Musculoskeletal ultrasonography (MSUS) is a useful tool for the diagnosis of several Rheumatic and Musculoskeletal Diseases (RMDs) but its role in the diagnostic pathways in clinical practice is still unclear as feasibility issues limit its application as a bed side technique.

Objectives

To optimize the use of US in clinical practice, the MSUS Study Group of the Italian Society for Rheumatology aimed to develop an algorithm combining US with clinical and laboratory findings to improve the differential diagnosis among patients presenting with joint swelling.

Methods

Based on a systematic literature review1 and experts’ opinion, MSUS Study Group Members attempt to identify a set of statements including the main US elementary lesions useful for US scanning in the suspicion of Rheumatoid arthritis (RA), Psoriatic arthritis (PsA), Rheumatic Polymyalgia (PMR), Gout, Calcium Pyrophosphate Deposition Disease (CPPD), Osteoarthritis (OA). Then, the MSUS Study Group defined through a survey and ranked in a 1000minds exercise the most important clinical/laboratory findings for the differential diagnosis of those diseases. Higher-ranked items were fitted in an algorithm driving the differential diagnosis of RMDs to a reduced spectrum of 2 to 4 possible diseases. Finally, the algorithm supported the performance of US according to the established scans for those specific diseases. To assess the algorithm’s performance, a pilot study was conducted on 59 patients, comparing the algorithm-based diagnosis with the final diagnosis based on rheumatologist’s experience and/or on classification criteria.

Results

Sets of elementary US lesions and a scanning protocol for each included pathology were created (Table 1), optimized towards high sensibility and specificity. Among the findings evaluated, the age (<50 / ≥50 years old), the number of the involved joints (monoarticular/polyarticular), the serology (Rheumatoid Factor [RF] and anti-citrullinated protein antibody [ACPA]); the acute-phase reactants (C-reactive protein [CRP]; erythrocyte sedimentation rate [ESR]) reached the higher ranking in the survey and were introduced in the algorithm, showed in Figure 1. In the pilot study, the algorithm-based diagnosis was consistent with the final diagnosis in 52 cases (accuracy 88.1%). Among the 7 cases in which the algorithm misclassified patients, four patients had a final diagnosis of OA (3 diagnosed by the algorithm as PMR/RA/PSA and one as PSA), one gout (algorithm diagnosis: OA/CPPD/PSA), one RA (algorithm diagnosis: Gout/CPPD/PSA) and one CPPD (algorithm diagnosis: PMR/RA/PSA).

Table 1.

Elementary ultrasound lesions and joints to be scanned for each included pathology

DiseaseSites to scanUS elementary lesionsRAII-IV MCPsSynovial Hypertrophy (SH), Power Doppler (PD), erosionsWristV MTPPsAII-III MCPsPeritendonitisPIPsEnthesitisSoft tissue oedemaFlexor tendons of the handsTenosynovitisSoft tissue oedemaAchille’s tendon enthesisPD, erosionsProximal patellar tendon enthesisCPPDKnees (menisci and Hyaline Cartilage)CPP depositsWrist (triangular fibrocartilage complex)Any involved sitesCPP deposits, SH, PDGoutKneesDouble contour, tophiI MTPInvolved sitesSHPDOAInvolved sitesOsteophytesCartilage changesPMRShouldersBursitisArthritisRotator cuff integrityFigure 1.

The final algorithm

Conclusion

The diagnostic algorithm produced in this pilot study correctly classified patients with the most prevalent RMDs in clinical practice. A longitudinal study on a large sample size is ongoing to evaluate the added value of US when implemented in this algorithm regarding diagnostic certainty, accuracy and early diagnosis.

References

[1]Sakellariou G, Scirè CA, Adinolfi A, Batticciotto A, Bortoluzzi A, Delle Sedie A, et al. Differential Diagnosis of Inflammatory Arthropathies by Musculoskeletal Ultrasonography: A Systematic Literature Review. Front Med. 7 maggio 2020;7:141.

Disclosure of Interests

None declared

POS0278 COMPARISON OF ULTRASOUND BEAM ATTENUATION BY CALCIUM PYROPHOSPHATE, HYDROXYAPATITE AND MONOSODIUM URATE CRYSTALS: A PROOF-OF-CONCEPT STUDY

Background

Ultrasound (US) demonstrated to be reliable and accurate for the diagnosis of crystal induced arthropathies, especially gout and calcium pyrophosphate deposition disease (CPPD) and validated definitions for uric acid and calcium pyrophosphate deposition in joints were released by the Outcome Measures in Rheumatology (OMERACT) US group. Less is known regarding hydroxyapatite (HA) deposition disease (HAAD) and the role of US in the assessment of HA crystal deposition.

It is general belief that HA crystals create posterior acoustic shadowing, monosodium urate could create or not US beam attenuation while CPP crystals generally do not attenuate the US beam.

Objectives

Aim of this proof-of-concept study was to investigate the US appearance in terms of beam attenuation due to increasing concentrations of MSU, CPP and HA crystals.

Methods

Sixteen synthetic crystal suspensions with known concentrations of CPP (26-109 mg/mL), HA (31-153 mg/mL) and MSU (90-500 mg/mL) were prepared. These specific concentrations were selected to replicate the X-ray attenuation characteristics of those crystals when imaged by conventional radiography, computed tomography (CT) and dual-energy CT (DECT) in vivo[1]. The density of the agar-based lipogel background was intentionally increased to mimic the X-ray attenuation of hyaline cartilage (i.e., 100-120 HU at 120 kVp). Each crystal suspension was placed in a plastic container filled with US gel, next to the control (i.e., crystal-free background) calibration phantom. We acquired all US images using a Samsung RS80A system equipped with a high-frequency linear array transducer (4-18 MHz) set at the maximum frequency, by applying the same settings. US scans were performed by a single experienced sonographer, blinded to the crystal type and concentration. For each of the 16 crystal suspensions, at least two images were recorded both in the long- and short-axis views, the latter including the control phantom in the field of view. Interpretation of US images for the extent of US beam attenuation and the presence of acoustic shadowing was performed in consensus with a second experienced sonographer.

Results

None of the five CPP phantoms generated posterior acoustic shadowing or US beam attenuation regardless of CPP concentration. HA 31mg/mL did not generate US beam attenuation, while HA 62, 92 and 123 mg/mL generated a progressively increasing US beam attenuation with posterior acoustic shadow clearly generated by HA 153 mg/mL. Similarly, MSU 90 mg/mL did not generate US beam attenuation. MSU 195 mg/mL generated only a very faint US beam attenuation that became progressively more visible at 270 and 345 mg/mL even if a clear posterior acoustic shadow was detectable only with MSU 420 and 500 mg/mL (Figure 1).

Figure 1.

Short-axis views comparing the US attenuation characteristics, including acoustic shadowing, of increasing concentrations (in mg/mL) of CPP, HA and MSU crystals. The left column shows the US attenuation of the crystal-free (0 mg/mL) agar-based lipogel background for reference

Conclusion

This proof-of-concept study confirmed that in the concentrations of crystals encountered in vivo, CPP do not generate posterior shadowing, while MSU and HA determine US beam attenuation proportionally to the concentration of the crystals. Being this a proof-of-concept study, attenuation of the US beam was assessed empirically and not in a quantitative or semi-quantitative way. However, this study highlights the potential of US to differentiate between CPP, MSU and HA crystals based on their appearance on gray scale imaging. Future studies should be carried out with different crystal concentrations, different US equipment and settings, in order to create a scoring system for US beam attenuation that is actually lacking.

References

[1]Pascart T et al. Dual-energy computed tomography in calcium pyrophosphate deposition: initial clinical experience. Osteoarthritis Cartilage 2019;27:1309–14. doi:10.1016/j.joca.2019.05.007

Disclosure of Interests

None declared

POS0023 PREVALENCE AND IMPACT OF FIBROMYALGIA SYNDROME IN A COHORT OF PATIENTS WITH INFLAMMATORY BOWEL DISEASE

Background

Fibromyalgia (FM) is a common chronic disorder characterized by widespread pain, fatigue, sleep disturbances and functional symptoms, reaching a prevalence of 2–3% worldwide. It can present as a comorbidity in patients with concomitant chronic disease and can have a significant impact on the quality of life. There are very few studies on the prevalence and the impact of FM in patients with inflammatory bowel disease (IBD).

Objectives

The aims of this study were to assess the prevalence of FM in a cohort of patients with IBD, and to evaluate the impact of FM on the quality of life of those patients.

Methods

Consecutive patients with IBD were enrolled from August to November 2021 in two IBD units, patients with severe disease activity according to the Crohn’s disease activity index (CDAI) and to the Mayo score for UC, or with other concomitant chronic diseases were excluded. Clinical and demographic data and Patient Reported Outcomes (PROs) (Widespread Pain Index (WPI), Symptom Severity Score (SSS), IBD Questionnaire (IBD-Q), Depression anxiety stress scales-21 (DASS-21), Functional Assessment of Chronic Illness Therapy-Fatigue (FACIT-F), Impact of event scale-revised (IES-R), Pittsburgh Sleep Quality Index (PSQI)) were collected. FM was diagnosed according to 2011 ACR classification criteria by an expert rheumatologist. Mann-Whitney test, chi-square test, and Student t test were used for statistical analyses. A multivariate analysis was performed to estimate the effect of independent variables (BMI, age, CRP, CDAI, Mayo score, WPI, DASS-21, FACIT-F, PSQI) on patients’ quality of life (IBD-Q). A p value < 0.05 was considered as significant.

Results

A total of 196 IBD patients were enrolled (86 female (44%) with a mean age of 50 ± 15 yo), 105 with Crohn’s disease (CD) and 91 with ulcerative colitis (UC). 147 patients were in remission, 35 had low disease activity and 14 moderate disease activity. The overall prevalence of FM in the IBD cohort was 17/196 (8.7%) [95% IC 5% – 13%], 10 (11.6%) women and 7 (6.3%) men; with a prevalence of 7.6% (8/105) in CD and 9.9% (9/91) in UC.

In Table 1 are indicated the characteristics of patients with IBD + FM and IBD alone. No significant demographic and clinical differences between the two groups were detected.

Table 1.IBD + FM (n=17)IBD without FM (n=179)pFemale/Male (%)10/7 (59%/41%)75/102 (42%/58%)0.19Age, years (SD)56.8 (± 13)48.5 (± 17)0.06BMI (SD)21 (± 8.7)23.7 (± 4.8)0.46CD (%)/UC (%)8 (47%)/9 (53%)97 (54%)/82 (46%)0.57CRP, median (SD)0.16 mg/dL (± 2.8)0.2 mg/dL (± 1.5)0.87IBD remission14 (82%)133 (74%)0.33IBD low disease activity1 (6%)34 (19%)IBD moderate disease activity2 (12%)12 (7%)Ongoing conventional treatment6 (35%)70 (39%)0.27Ongoing biological treatment11 (65%)112 (63%)0.42 PROsIBD-Q150.3176.9<0.001DASS-21 DEPRESSION15.38.24<0.001DASS-21 ANXIETY16.69.13<0.001DASS-21 STRESS13.46.13<0.001FACIT-F25.538.2<0.001IES-R36.916.3<0.001

The quality of life among IBD patients and IBD + FM patients, assessed with IBD-Q, appear significantly lower (p <0.001) in the second group. Similar results were obtained evaluating depression, anxiety, stress, chronic fatigue, and patients’ discomfort (Table 1).

The multivariate analysis demonstrated that the variables influencing the quality of life (IBD-Q) were the disease activity (CDAI) (p 0.0256), the chronic fatigue (FACIT-F) (p 0.0061) and sleep disturbances (PSQI) (p 0.0440), for CD; while for UC the only variable that correlate with IBD-Q was the disease activity (Mayo score) (p 0.0129).

Conclusion

FM is a common disorder especially in patients with other concomitant chronic diseases. This study reported a prevalence of FM of 8.7% in IBD patients without any significant differences between CD and UC. Moreover, the comorbidity of FM in IBD can have a considerable impact on quality of life and on measures of disease severity, with worst values in all PROs measurements.

Disclosure of Interests

None declared

OP0168 DEVELOPMENT OF AN ULTRASOUND SCORING SYSTEM FOR CPPD EXTENT: RESULTS FROM A DELPHI PROCESS AND WEB-RELIABILITY EXERCISE BY THE OMERACT US WORKING GROUP

Background

Ultrasound (US) has proven to be an excellent imaging technique for detecting calcium pyrophosphate (CPP) deposition disease (CPPD); it is also widely available and inexpensive and can be performed during the clinic visit making it the preferred imaging modality for many rheumatologists. However, no validated grading systems have yet been developed allowing for a quantification of the extent of crystal deposition in CPPD.

Objectives

The aim of this study was to develop a scoring system for the quantification of CPP deposition at a patient level according to the OMERACT framework.

Methods

As part of the OMERACT methodology, we performed a systematic literature review (SLR) and meta-analysis aimed to estimate the prevalence of CPP deposition in peripheral joints by imaging, in order to identify relevant joints for CPPD monitoring. A preliminary survey was also circulated among the members of the OMERACT US – CPPD working group to collect their own suggestions according to their personal experience. Subsequently, a Delphi survey was prepared and circulated between members of the group, including statements that reflected both the results of the SLR and of the preliminary survey. In total, 32 statements were generated regarding the type of scoring for single structures, the sites to be included, the final scoring at patient level, and the scanning technique. Participants were asked to reply on a 5-point Likert scale (1, strongly disagree to 5, strongly agree) and agreement was achieved when 4 and 5 grades reached 75% or more of concordance. In case of disagreement, new statements were proposed according to the members’ suggestions and circulated for voting in a subsequent round. After agreement of a scoring system, the validation process began. Two rounds of a web-based exercise on static images were conducted on 120 images representing equally all sites under investigation and all degrees of crystal deposition, to assess the intra- and inter-reader reliability of the new scoring system. Representative images of the scoring system were visible throughout the entire exercise in order to facilitate the scoring of the lesions.

Results

Three Delphi rounds were needed to reach agreement on all items. 32/41 members of the OMERACT US-CPPD working group replied in the first round, 26/32 in the second, and 25/26 in the third round. Twenty statements were approved in the first round, 3 in the second, and 3 in the third round. Only the knees (menisci and hyaline cartilage) and the triangular fibrocartilage of the wrist were included in the final score, using a four-grade system (0-3). It was decided that each anatomical structure should be scored separately and then also summed in order to define the joint score. The sum of the assessed joints was the total score at patient level. The final scoring system with the definitions and the relative technical notes is represented in Figure 1. 33/41 members participated to the reliability exercise. The inter-reader reliability of the scoring was substantial (kappa of 0.72), and the intra-reader reliability was almost perfect (kappa of 0.82).

Conclusion

This is the first study for developing a scoring system for the extent of CPP crystal deposition in patients with CPPD. The scoring system demonstrated to be reliable in static images. The next step of the validation process is to assess the reliability of the scoring system in a patient-based exercise. This study represents a fundamental step in the OMERACT process of validating US as an outcome measure instrument, and above proposed scoring system will hopefully provide a useful tool for clinical practice and research.

Disclosure of Interests

None declared

POS0276 TRADITION VS INNOVATION! CONVENTIONAL RADIOGRAPHY AND ULTRASOUND IN THE DIAGNOSIS OF CPPD: INSTRUCTIONS FOR USE

Background

Conventional radiography (CR) is widely used as the first-line investigation for calcium pyrophosphate deposition (CPPD) disease, given its widespread use and the low cost. Next to it a series of advanced imaging techniques have been evaluated for accuracy and reliability. Among them, ultrasound (US) has been thoroughly tested and demonstrated to be accurate and reliable for CPPD diagnosis. However, even if there are data on the diagnostic accuracy of US and CR alone, it is not clear if performing both diagnostic tests and in which sequential order provides an added value for the diagnosis of CPPD.

Objectives

The aim of this study was to assess which diagnostic test performs better for the diagnosis of CPPD and if a combination of the two exams provides an additional value.

Methods

This is an ancillary study of the criterion validity of US in CPPD study1. Consecutive patients with knee osteoarthritis requiring total joint replacement were enrolled in 8 centres. Participants underwent US and CR of the affected knee prior to surgery. US was performed by experienced sonographers following the same scanning protocol described in the main study, while CR were performed in weight bearing AP and lateral views and were read by 2 experienced radiologists that reached a consensus on the presence/absence of CPPD. The evaluation of CPPD at the level of menisci and hyaline cartilage (HC) was based on the OMERACT definitions for US and on the new definitions developed by the ACR/EULAR CPPD classification criteria working group for CR [paper under submission]. Patients were classified as having CPPD considering histological examination as reference standard. Diagnostic indexes were calculated for US and CR alone and combined. Poisson models with robust estimation were used to estimate the best sequence of these diagnostic methods for a more accurate diagnosis of CPPD.

Results

51 pts were enrolled (63% F, mean age 74y ± 8). Diagnostic indexes of US and CR alone and combined are indicated in Table 1. Compared to histology, US demonstrated to be a sensitive tool for identification of CPPD at the knee, with a good sensitivity in all sites and in the overall evaluation. Instead, CR was less sensitive, but it was a highly specific exam for CPPD identification. Combining US and CR led to a higher sensitivity compared with CR alone, but a lower specificity compared to both CR and US alone, and it offered no additional increase in diagnostic accuracy. The Figure 1 shows the results of the appropriate sequence of use of US and CR in patients with suspected CPPD: in case of a positive CR at any of the 3 sites (menisci and HC) no additional exam is necessary, and the same in case of a positive US in at least two sites; however in case of a negative CR, US could help in a statistically significant way to identify CPPD patients, and further in case of a positive US in a single site CR can offer additional information.

Table 1.

diagnostic indexes of US, CR and US + CR in the identification of CPPD. MM: medial meniscus, LM: lateral meniscus, HC: hyaline cartilage, SN: sensitivity, SP: specificity, PPV: positive predictive value, NPV: negative predictive value, ACC: accuracy.

USSNSPPPVNPVACCMM0.880.810.820.880.84LM0.880.730.760.860.80HC0.780.860.820.830.82Overall0.920.640.730.890.78CRMM0.32110.610.67LM0.400.960.910.630.69HC0.480.930.850.680.73Overall0.540.920.880.660.73US + CRMM0.880.810.820.880.84LM0.920.690.740.900.80HC0.870.820.800.890.84Overall0.920.560.670.880.75Figure 1.

evaluation of sequence of US and CR

Conclusion

US confirmed a high diagnostic accuracy in identifying patients affected by CPPD at knee level, while CR demonstrated a high specificity but a low sensitivity. Performing both diagnostic tests could make sense in case of a negative CR or in case of an inconclusive US (only one positive site). To our knowledge, this is the first study that investigates the role of the combination of the two exams in CPPD. Further studies in a large number of patients and in different joints would be helpful to address this point.

References

[1]Filippou G. et al, Ann Rheum Dis, 2020

Disclosure of Interests

None declared

OP0291 SCORING STRUCTURAL DAMAGE IN RHEUMATOID ARTHRITIS BY ULTRASOUND: RESULTS FROM A DELPHI PROCESS AND WEB-RELIABILITY EXERCISE BY THE OMERACT US WORKING GROUP

Background

Structural damage in rheumatoid arthritis (RA) includes bone erosion, cartilage change, and joint malalignment; historically evaluated with conventional radiography. Ultrasound (US) has been shown to be a valid tool for evaluating both cartilage change and bone erosion.

Objectives

To obtain agreement on definitions and develop semiquantitative scoring systems for assessing structural damage by US and to validate these in a web-based reliability exercise.

Methods

A Delphi survey of statements was prepared by an OMERACT US Working Group task force (USWG) based on a previously published systematic literature review (1) and circulated between group members, including definitions on normal US appearance of joint components, definitions of elementary lesions and scoring systems for bone erosions and joint malalignment. Definitions and a US scoring system for scoring cartilage change were recently developed and validated by the USWG (2) After agreement was achieved (≥75% of grades 4-5 on 1-5 Likert scale) on the statements, still images of metacarpophalangeal and proximal interphalangeal joints 2-5 in healthy controls and in RA patients with varying degrees of pathology were acquired by the USWG members. A dataset of 100 anonymized images, representing various grades of the 3 components of structural damage was created and utilized in 2 rounds of a web-based exercise. Intra- and inter-reader reliability of the scoring systems was assessed by kappa statistics.

Results

19 USWG members needed 4 Delphi rounds to reach agreement on a total of 9 statements. 4/12 statements were approved in the first, 2/6 in the second, 1/5 in the third and 2/2 in the fourth round. Final scoring systems and representative images are shown in Table 1 & Figure 1. 22 members participated in the web-based reliability exercise. The intra-reader reliability was almost perfect for bone erosion (kappa: 0.87) and cartilage change (kappa: 0.83) and substantial for malalignment (kappa of 0.72). The inter-reader reliability was almost perfect for bone erosion (kappa: 0.85), and substantial for cartilage change (kappa: 0.79) and malalignment (0.62).

Table 1.

Final definitions of scoring systems of elementary lesions of structural damage in rheumatoid arthritis

AgreementBone erosionA 4-grade semiquantitative scoring system can be used to score erosions as follows: grade 0. intact cortical bone; grade 1. single small erosion (diameter: ≤2mm); grade 2. single large erosion (diameter: >2mm) or 2 small erosions; grade 3. 2 large erosions or ≥3 erosions, regardless of size. Both longitudinal and transverse scans should be considered, and the largest measure chosen for each erosion.100%Cartilage changeA 3-grade semiquantitative scoring system can be used to grade hyaline cartilage change as follows: grade 0. normal cartilage; grade 1. minimal change: focal thinning or incomplete loss of cartilage; grade 2. severe change: diffuse thinning or complete loss of cartilage.80% (2)MalalignmentA 3-grade semiquantitative scoring system can be used to grade malalignment as follows: 0. normal alignment; 1. subluxation or partial dislocation, where the two bone endings are malaligned so that one bone ending is dislocated from its normal position, but still within the articulation; 2. luxation or total dislocation, where the luxated bone ending moves beyond the articulation and the opposing bone ending. Bone position may be compared with a contralateral or similar intact joint if available.94%Figure 1.

Representative images of the scoring systems for bone erosion (A), cartilage change (B) and malalignment (C)

Conclusion

This first attempt to create a composite US instrument based on scoring systems encompassing all aspects of structural damage, demonstrates that US is a reliable tool for evaluating and scoring bone erosion, cartilage change and malalignment in the finger joints of RA patients.

References

[1]Gessl I, et al. Semin Arthritis Rheum. 2021 Jun;51(3):627-39.

[2]Mandl P, et al. Rheumatology (Oxford). 2019 Oct 1;58(10):1802-11.

Disclosure of Interests

Peter Mandl Speakers bureau: AbbVie, Janssen, Lilly, Novartis, Consultant of: AbbVie, Janssen, Lilly, Novartis, Grant/research support from: AbbVie, BMS, Novartis, Janssen, Lilly, MSD, UCB, Irina Gessl: None declared, Georgios Filippou: None declared, Silvia Sirotti: None declared, Lene Terslev Speakers bureau: Novartis, Pfizer, UCB, Janssen, GE, Carlos Pineda: None declared, Helen Keen Speakers bureau: Roche, AbbVie, Janssen, Consultant of: Sanofi, Marina Backhaus: None declared, David Andrew Bong: None declared, Edoardo Cipolletta: None declared, PAZ COLLADO: None declared, Christian Dejaco Speakers bureau: Roche, AbbVie, Sanofi, Lilly, Pfizer, Novartis, Janssen, Galapagos, Consultant of: Roche, AbbVie, Sanofi, Lilly, Pfizer, Novartis, Janssen, Galapagos, Andrea Delle Sedie Speakers bureau: Abbvie, Amgen, Lilly, MSD, Novartis, UCB, Paid instructor for: Abbvie, Amgen, Lilly, MSD, Novartis, UCB, Consultant of: Abbvie, Amgen, Lilly, MSD, Novartis, UCB, Christina Duftner: None declared, Hilde Berner Hammer: None declared, Annamaria Iagnocco: None declared, Zunaid Karim: None declared, Ingrid Möller Speakers bureau: Bristol-Myers Squibb, Ibsa, Pfizer, Galapagos, Esperanza Naredo Speakers bureau: Abbvie, Pfizer, Lilly, Novartis, Janssen, Celgene GmbH, Paid instructor for: Novartis, Consultant of: Novartis, Lilly, Grant/research support from: Lilly, Pfizer, Wolfgang A. Schmidt: None declared, Marcin Szkudlarek: None declared, Giorgio Tamborrini: None declared, Priscilla C Wong: None declared, Emilio Filippucci Speakers bureau: AbbVie, Amgen, Bristol -Myers Squibb, Janssen-Cilag, Lilly, Novartis, Pfizer, Roche, Union Chimique Belge Pharma, Peter Balint Speakers bureau: Abbvie, Janssen, Lilly, Novartis, Maria-Antonietta D’Agostino: None declared

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

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

AB0629 ACCURACY OF SYNOVIAL FLUID ANALYSIS FOR THE IDENTIFICATION OF CALCIUM PYROPHOSPHATE CRYSTALS: AN ANCILLARY STUDY OF OMERACT CRITERION VALIDITY STUDY FOR ULTRASOUND IN CPPD

Background:

Synovial fluid analysis (SFA) via compensated polarized light microscopy is still considered the gold standard for the identification and diagnosis of Calcium Pyrophosphate Deposition disease (CPPD)-related arthropathies[1], but very few studies have been published about its diagnostic accuracy.

Objectives:

The aim of this study was to evaluate the accuracy of SFA in the identification of calcium pyrophosphate dihydrate (CPP) crystals compared to microscopic analysis of joint tissues as the reference standard.

Methods:

This is an ancillary study of an international, multicentre cross-sectional study performed by the CPPD subgroup of the OMERACT Ultrasound working group[2]. Consecutive patients with knee osteoarthritis (OA) waiting for total knee replacement surgery were enrolled in the study from 2 participating centres, Mexico and Romania. During surgical procedures synovial fluid (SF), menisci and hyaline cartilage were collected and analysed within 48 hours after surgery under transmitted light microscopy and compensated polarised light microscopy for the presence/absence of CPP crystals. All slides were analysed by expert examiners on site, blinded to other findings. A dichotomic score (absence/presence) was used for scoring both SF and tissues. Microscopic analysis of knee tissues was considered the gold standard. Sensitivity, specificity, accuracy, positive and negative predictive values (PPV and NPV) of SFA in the identification of CPP crystals were calculated.

Results:

15 patients (53% female, mean age 68yo ± 8.4) with OA of grade 3 or 4 according to Kellgren-Lawrence scoring were enrolled. 12 patients (80%) were positive for CPP crystals at SFA and 14 (93%) at tissues microscopic analysis. Among 12 SFA positive patients, all were positive for CPP crystals in either medial or lateral meniscus, and 11 were positive in both; 10 patients were positive at the hyaline cartilage, and all 10 were also positive for at least one meniscus. Regarding the 3 SFA negative patients, only one had no crystals in the examined tissues, while the other 2 patients had CPP crystals in both menisci and hyaline cartilage. The overall diagnostic accuracy of SFA compared to histology analysis for CPPD was 87%, with a sensitivity of 86% and a specificity of 100%, the PPV was 100% and the NPV was 33% (Table 1).

Table 1.

sensitivity, specificity, positive predictive value (PPV), negative predictive value (NPV) and diagnostic accuracy of synovial fluid analysis compared to the reference standard. CI: Confidential Interval. SF: synovial fluid, in parentheses: numerators and denominators for all percentages provided.

SensitivitySpecificityPPVNPVAccuracySF analysis86% (12/14)100% (1/1)100% (12/12)33% (1/3)87% (13/15)(0.65-0.99) CI 95%(0.0-0.25) CI 95%(0.65-0.99) CI 95%(0.0-0.25) CI 95%

Conclusion:

SFA demonstrated to be an accurate test for the identification of CPP crystals in patients with advanced OA. However, is not always feasible and carries some risks for the patient. Considering the availability of validated imaging techniques for the detection of CPPD, such as US, SFA could be used in those patients where imaging and clinical data are not definitely confirmatory of the disease.

References:

[1]W. Zhang et al., ‘European League Against Rheumatism recommendations for calcium pyrophosphate deposition. Part I: terminology and diagnosis’, Ann Rheum Dis, vol. 70, no. 4, pp. 563–570, Apr. 2011, doi: 10.1136/ard.2010.139105.

[2]G. Filippou et al., ‘Criterion validity of ultrasound in the identification of calcium pyrophosphate crystal deposits at the knee: an OMERACT ultrasound study’, Ann Rheum Dis, p. annrheumdis-2020-217998, Sep. 2020, doi: 10.1136/annrheumdis-2020-217998.

Disclosure of Interests:

None declared.

POS1132 DIAGNOSTIC ACCURACY OF CONVENTIONAL RADIOGRAPHY OF THE KNEE FOR CALCIUM PYROPHOSPHATE DEPOSITION DISEASE: AN ANCILLARY STUDY OF THE OMERACT ULTRASOUND – CPPD GROUP

Background:

Conventional Radiography (CR) has been widely used in the assessment of knee chondrocalcinosis (CC) and is still considered one of the most important diagnostic methods for the diagnosis. However, there are very few studies that examine the diagnostic accuracy of CR compared to histology of the knee tissues.

Objectives:

To assess the diagnostic accuracy of CR of the knee in Calcium Pyrophosphate Deposition Disease (CPPD) by using the recently created definitions for CPPD in CR of the ACR/EULAR taskforce for the new classification criteria for CPPD.

Methods:

This is an ancillary study of the Criterion Validity of Ultrasound in CPPD study [1]. Consecutive patients with osteoarthritis (OA) awaiting total knee replacement were enrolled in 4 centres from Romania, Italy, USA and Mexico. All patients underwent CR of the knees taken maximum 6 months before surgery, in posterior-anterior weight baring and lateral projections. DICOM files of the radiographs were anonymised and read independently by two musculoskeletal radiologists with experience in microcrystalline arthropathies. For each patient, a dichotomic score was used (absence/presence of CC) at the level of the menisci and tibiofemoral hyaline cartilage by each reader. The definitions of the ACR/EULAR taskforce for identification of CPPD in CR were used in this study [paper in preparation]. According to these definitions CPPD in CR appears as “linear or punctate opacities in the region of fibro- or hyaline articular cartilage/synovial membrane or joint capsule/within tendons or entheses that are distinct from denser, nummular radio-opaque deposits due to basic calcium phosphate deposition”. In case of disagreement a consensus decision was taken by both radiologists after discussion of the case. Menisci and the hyaline cartilage were analysed using compensated polarized light microscopy as described previously [1], patients were considered positive for CPPD if at least one of their tissue specimens revealed the presence of calcium pyrophosphate crystals. All examiners were blind to each other’s findings.

Results:

We enrolled 33 patients with OA (61% female, mean age 69yo). The accuracy values of CR in the various sites of the knee are indicated in Table 1. CR demonstrated to be a specific exam for identification of CPPD at the knee, but sensitivity remains low in all sites and in the overall evaluation. Identification of CPPD appears challenging and this could be due to the advanced grade of OA in our cohort of patients. Advanced degeneration, dislocation of the menisci and thinning of the hyaline cartilage in these patients is frequent and the eventual presence of calcific deposits in one of these structures could overlap with other anatomical structures making the exact localisation difficult. According to the results of the predictive values, the presence of typical deposition on CR allows a definite confirmation of the diagnosis, but a negative radiography does not exclude CPPD as testified by the low negative predictive value.

Table 1.

Sensitivity, specificity, PPV, NPV, accuracy and AUC of CR for identification of CPPD by using the new ACR/EULAR taskforce definitions.

Medial meniscusLateral meniscusHyaline cartilageOverallSensitivity22%33%31%42%Specificity100%100%85%90%Positive predictive value100%100%67%80%Negative predictive value56%60%55%61%Accuracy61%68%58%66%AUC0.60.70.60.7

Conclusion:

CR has been extensively used for the diagnosis of OA and CPPD and has been tested previously for diagnostic accuracy. The results of our study confirm that the presence of typical CPPD calcifications, as defined by the ACR/EULAR task force, are highly specific but have low sensitivity for disease identification when using CR. Absence of CPPD on CR does not exclude the diagnosis.

References:

[1]Filippou G, et al. Criterion validity of ultrasound in the identification of calcium pyrophosphate crystal deposits at the knee: an OMERACT ultrasound study. Ann Rheum Dis 2020. doi:10.1136/annrheumdis-2020-217998

Disclosure of Interests:

None declared.

POS1141 ASSESSING RELEVANT JOINTS FOR MONITORING CPPD DISEASE: A SYSTEMATIC LITERATURE REVIEW OF IMAGING TECHNIQUES BY THE OMERACT ULTRASOUND – CPPD SUBGROUP

Background:

Imaging has been extensively used for the Calcium Pyrophosphate Deposition Disease (CPPD) diagnosis but the prevalence of joint calcifications at imaging in CPPD patients has not been thoroughly assessed.

Objectives:

This systematic literature review (SLR) is aimed to estimate the prevalence of calcium crystal deposition in peripheral joints by imaging in suspected or definite CPPD patients to establish relevant joints for CPPD monitoring

Methods:

After defining PICOs, Pubmed and Embase were searched from inception to October 2020 for identifying studies that evaluated the use of Conventional Radiography (CR), Ultrasound (US), Computed Tomography (CT) and Dual Energy Computed Tomography (DECT) in detecting calcifications at peripheral joints in patients with defined or probable CPPD. Search strategies based on MeSH terms and free text were applied. Six reviewers independently screened titles and abstracts, eligible article full texts were evaluated for inclusion and data extraction.

Results:

The SLR identified 1149 manuscripts. 524 papers entered in the full text evaluation and 181 articles were finally included. Considering excluded abstracts and full texts, 23 and 17 were excluded as duplicate, 156 and 9 for language, 171 and 48 for population, 171 and 20 for intervention, 57 and 117 for outcome, 47 and 70 for study type and 76 for full text unavailability. Among included, 41 papers considered patients with definite CPPD with a total population of 1239 patients, 908 cases and 331 controls and 140 papers referred to patients with suspected CPPD with a total population of 26785 patients, 2896 affected by CPPD and 23889 controls. The results about all joints are summarized in the Table 1. In patients with definite diagnosis, knee and wrist are the joints with the highest prevalence of calcifications at all imaging types, followed by hip and acromion-clavicular joint while in patients with suspected CPPD, the knee is the most prevalent followed by the wrist, hip and ankle (only sites with more than 50 patients assessed considered). The hand joints are characterized by CPPD lowest prevalence at imaging. Bilateral imaging findings varies depending on the technique used, the site and the patient’s type.

Table 1.

Definite CPPD Diagnosis

KNEEWRISTHANDELBOWSHOULDERACHIPANKLEFOOTTMXRImaging positive cases/all cases330/584 57%214/409 52%43/158 27%54/212 25%65/249 26%37/84 44%140/293 48%30/255 12%15/59 25%0Cases positivebilaterally99/146 68%30/79 38%0/104/12 33%2/2 100%9/17 53%7/10 70%7/10 70%00USImaging positive cases/all cases155/252 62%86/118 75%4/42 9%2/2 100%0/304/30 13%47/80 59%30/255 12%15/59 25%0Cases positivebilaterally83/96 86%33/47 70%1/ 4 25%003/ 4 75%29/47 62%7/10 70%00CTImaging positive cases/all cases41/50 82%22/28 78%00000000Cases positivebilaterally27/30 90%000000000DECTImaging positive cases/all cases8/10 80%9/10 90%1/1 100%0000000Cases positivebilaterally001/1 100%0000000Suspected CPPD diagnosisKNEEWRISTHANDELBOWSHOULDERACHIPANKLEFOOTTMXRImaging positive cases/all cases1989/2442 81%549/1024 54%98/602 16%29/72 40%75/185 41%27/31 87%322/887 36%56/116 48%24/42 57%0Cases positive bilaterally611/1068 57%209/334 63%64/85 75%22/23 96%41/46 89%0/294/196 48%44/53 83%18/19 95%0USImaging positive cases/all cases241/261 93%125/185 68%2/39 5%1/1 100%4/12 33%02/2 100%27/78 35%8/37 22%0Cases positivebilaterally4/9 44%74/93 80%00000000CTImaging positive cases/all cases019/23 83%002/2 100%02/2 100%001/1 100%Cases positivebilaterally0000000001/1 100%DECTImaging positive cases/all cases1/1 100%2/2 100%00000000Cases positivebilaterally1/1 100%000000000

Table 1 For each joint, are summarized the ratio between positive joints and overall evaluated joints and the ratio between the joints positive bilaterally and overall joints evaluated bilaterally.

AC Acromion Clavicular, TM temporo mandibular

Conclusion:

According to the results of this SLR, knees and wrists could be the sentinel joints for CPPD detection by imaging.

Disclosure of Interests:

None declared.

POS1133 RELIABILITY OF CONVENTIONAL RADIOGRAPHY OF THE KNEE FOR THE ASSESSMENT OF CHONDROCALCINOSIS: AN ANCILLARY STUDY OF THE OMERACT ULTRASOUND – CPPD GROUP

Background:

Conventional Radiography (CR) has been widely used in the assessment of knee chondrocalcinosis (CC) and is still considered one of the most important diagnostic methods for the diagnosis. However, there are no studies on the reliability of CR for CC.

Objectives:

To assess the reliability of CR of the knee in the assessment of chondrocalcinosis (CC).

Methods:

This is an ancillary study of the Criterion Validity of Ultrasound in Calcium Pyrophosphate Deposition Disease (CPPD) study [1]. Consecutive patients with knee osteoarthritis (OA) that were planned for total knee replacement surgery were enrolled in 4 centres from Romania, Italy, USA and Mexico. All patients underwent CR of the knees taken maximum 6 months before surgery, in posterior-anterior weight baring and lateral projections. DICOM files of the radiographs were retrieved, anonymised and read independently by two musculoskeletal radiologists with experience in microcrystalline arthropathies. Each reader performed a second evaluation 3 weeks after the first one to calculate the inter- and intra-reader agreement. For each patient a dichotomic score was assigned (absence/presence of CC) at the level of the medial and lateral menisci, tibiofemoral hyaline cartilage, quadriceps and patella tendons, synovial membrane/joint capsule. The definitions of the ACR/EULAR taskforce for identification of CPPD in conventional radiography were used in this study [paper in preparation]. According to these definitions CPPD in CR appears as “linear or punctate opacities in the region of fibro- or hyaline articular cartilage/synovial membrane or joint capsule/within tendons or entheses that are distinct from denser, nummular radio-opaque deposits due to basic calcium phosphate deposition”. Cohen’s kappa was used to calculate the agreement between the two readers.

Results:

We enrolled 33 patients with knee OA (60.6% female, mean age 69yo ± 8). The kappa values of the inter-reader and intra-reader agreement in the various sites of the knee are indicated in Table 1. Inter-reader agreement was substantial at the level of both menisci but only moderate or fair at the other sites of assessment. This had a negative impact on the overall evaluation of the knee joint that proved to be unreliable (k of 0.16 – none to slight agreement) if all anatomical structures are included for assessment, and moderately reliable (kappa 0.41) when both menisci and hyaline cartilage are considered. On the other hand, intra-reader kappa values were substantial or higher in all sites (except for synovial membrane/joint capsule for one reader). The striking difference of the intra-reader compared to the inter-reader kappa values, highlight a different interpretation and application of the definitions used for most of the sites with the exception of the menisci.

Table 1.

kappa values for intra- and inter-reader agreement. Values from 0.01–0.20 are considered as none to slight agreement, 0.21–0.40 as fair, 0.41– 0.60 as moderate, 0.61–0.80 as substantial, and 0.81–1.00 as almost perfect agreement.

Medial meniscusLateral meniscusHyaline cartilageQuadriceps tendonPatellar tendonCapsule/ synoviaMenisci + cartilageEntire jointInter-reader0.670.710.340.47NA0.370.400.17Intra-reader 1st assessor0.670.900.840.65NA(insufficient number of categories)0.530.710.76Intra-reader 2nd assessor10.801110.910.860.94

Conclusion:

CR has been extensively used for diagnosis of OA and CPPD. The results of our study raise some concerns on the reliability of CR in identification of CPPD. Assessment of calcium crystals at the menisci level should be used for identification of CC as other sites of the knee seem to present low reliability.

References:

[1]Filippou G et al. Criterion validity of ultrasound in the identification of calcium pyrophosphate crystal deposits at the knee: an OMERACT ultrasound study. Ann Rheum Dis 2020. doi:10.1136/annrheumdis-2020-217998

Disclosure of Interests:

None declared.

AB0598 EFFICACY OF ULTRASOUND GUIDED INJECTIONS OF A CROSS-LINKED SODIUM HYALURONATE COMBINED WITH TRIAMCINOLONE HEXACETONIDE FOR OSTEOARTHRITIS OF THE KNEE

Background:

According to guidelines, the use of steroid and/or hyaluronate (HA) intra-articular injections for knee osteoarthritis (KOA) is controversial. Heterogeneity of studies and difference in HAs characteristics does not allow to draw safe conclusions. One of the major concerns is the accuracy of the procedure as up to 1/3 of injections could miss joint space when performed blindly (1), negatively affecting the efficacy of HA that needs to be placed correctly in the joint space

Objectives:

The aim of our study was to evaluate the longterm efficacy of a novel association of a Cross-Linked Sodium Hyaluronate Combined With Triamcinolone Hexacetonide (SHCTH) in patients with KOA in a real life setting.

Methods:

We retrospectively evaluated the clinical and ultrasonographic (US) data of patients (pts) affected by symptomatic KOA with intra-articular injections of SHCTH (1 injection every 6 months). Pts with concomitant inflammatory arthropaties were excluded. US guidance was carried out with the “in plane” technique choosing either the lateral suprapatellar or midpatellar approach. All pts were evaluated for pain with a VAS 0-10 for pain at baseline and after 2 weeks, 1, 3, 6, 9 and 12 months, with the WOMAC questionnaire and with US, scoring joint effusion, synovial hypertrophy (SH) and power Doppler (PD) synovial signal. Due to the retrospective design, the WOMAC data were available as VAS or Likert scales; to allow comparability these values were standardized. Clinical and US variables at different time points were compared using the Wilcoxon rank sing test, the McNemar test or the paired samples t-test, depending on the variable.

Results:

49 knees (43 pts, median age 70.6 years, 24 women) were included in the study. Kellgren Lawrence grade was 1 for 5 knees, 2 for 10, 3 for 17 and 4 for 9. SHCTH was delivered correctly in the joint space in all patients as assessed by US check during the injection and no side effects occurred. Of the 49 knees, 28 had an available 6 months follow-up, while 21 completed the 12 months follow-up, with an attrition mostly related to the COVID 19 pandemic. A rapid and sustained statistically significant decrease of both VAS pain and the WOMAC subscales was observed. The reduction of pain was already significant at 2 weeks, probably thanks to the corticosteroid component. At US evaluation, effusion significantly decreased at all time points. Although SH scores also significantly decreased, the effect on the proportion of affected joints was not as relevant. The reduction of PD was significant until month 9. Detailed results are presented in Table 1.

Conclusion:

Our data show that US guided SHCTH injections provide a rapid and sustained clinical response in patients with symptomatic OA. Besides the effect on pain, the US data confirm the effect of the drug on the inflammation. US guidance guaranteed the correct placement of the product in all patients and eliminated the bias of wrong placement that may occur with blind injections, thus allowing to draw safe conclusions on the efficacy of SHCTH for the treatment of KOA.

References:

[1]Jones A, Regan M, Ledingham J, et al. Importance of placement of intra-articular steroid injections. BMJ 1993;307:1329–30.

Table 1.

Table 1. Clinical and US measures. p values refer to the comparison with baseline. WOMAC subscales were compared by paired samples t test. *hypothesis test not applicable

baseline2 weeks1 month3 months6 months9 months12 monthsVAS (median,IQR)6 (5-8)3 (1-4.25) p<0.00012 (0.5-3-5) p<0.00011.5 (0-3) p<0.00011.5 (0-4) p<0.00011 (0-2.75) p<0.00011 (0-3.25) p<0.0001WOMAC pain--p 0.028p 0.0004p 0.0036p 0.0096p 0.0064WOMAC stiffness--p 0.048p 0.040p 0.0388p<0.0001p 0.0083WOMAC function--p 0.043p 0.0005p 0.0014p 0.01p 0.007Effusion 0-3 (median,IQR)2 (1-2)-1 (0-1) p<0.00011 (0-1) p<0.00011 (0-1) p 0.00010 (0-1) p<0.00011 (0-1) p<0.0001Synovial Hypertrophy 0-3 (median,IQR)1 (1-2)-1 (1-1) p 0.0021 (1-1) p 0.00011 (1-1) p 0.00011 (0-1) p 0.00011 (0.5-1) p 0.0001PD 0-3 (median,IQR)0 (0-0)-0 (0-0) p 0.030 (0-0) p 0.030 (0-0) P 0.061 (0-1) p 0.010 (0-0) p 0.31

Disclosure of Interests:

None declared.

POS1124 IDENTIFYING POTENTIAL CLASSIFICATION CRITERIA FOR CALCIUM PYROPHOSPHATE DEPOSITION DISEASE (CPPD): RESULTS FROM THE INITIAL PHASES

Background:

Classification criteria for calcium pyrophosphate deposition disease (CPPD) will facilitate clinical research on this common crystalline arthritis. ACR/EULAR are jointly sponsoring development of CPPD classification criteria using a multi-phase process.

Objectives:

To report preliminary results from the first two phases of a four-phase process for developing CPPD classification criteria.

Methods:

CPPD classification criteria development is overseen by a 12-member Steering Committee. Item generation (Phase I) included a scoping literature review of five literature databases and contributions from a 35-member Combined Expert Committee and two Patient Research Partners. Item reduction and refinement (Phase II) involved a Combined Expert Committee meeting, discussions among Clinical, Imaging, and Laboratory Advisory Groups, and an item rating exercise to assess the influence of individual items toward classification. The Steering Committee reviewed the modal rating score for each item (range -3 [strongly pushes away from CPPD] to +3 [strongly pushes toward CPPD]) to determine items to retain for future phases of criteria development.

Results:

Item generation yielded 420 items (312 from the literature, 108 from experts/patients). The Advisory Groups eliminated items they agreed were unlikely to distinguish between CPPD and other forms of arthritis, yielding 127 items for the item rating exercise. Fifty-six items, most of which had a modal rating of +/- 2 or 3, were retained for future phases (see Table 1). As numerous imaging items were rated +3, the Steering Committee recommended focusing on imaging of the knee, wrist, and one additional affected joint for calcification suggestive of CPP crystal deposition.

Conclusion:

The ACR/EULAR CPPD classification criteria working group has adopted both data- and expert-driven approaches, leading to 56 candidate items broadly categorized as clinical, imaging, and laboratory features. Remaining steps for criteria development include domain establishment, item weighting through a multi-criteria decision analysis exercise, threshold score determination, and criteria validation.

Table 1.

Categories of items retained for future phases of classification criteria development

Age in decade at symptom onsetAcute inflammatory arthritis (e.g. knee, wrist, 1st MTP joint*)Recurrence and pattern of joint involvement (e.g. 1 self-limited episode, >1 self-limited episode)Physical findings (e.g. palpable subcutaneous tophus*, psoriasis*)Co-morbidities and family history (e.g. Gitelman disease, hemochromatosis, familial CPPD)Osteoarthritis location and features (e.g. 2nd or 3rd MCP joint, wrist)Synovial fluid findings (e.g. CPP crystals present, CPP crystals absent on 1 occasion* or 2 occasions*, monosodium urate crystals present*)Laboratory findings (e.g. hypomagnesemia, hyperparathyroidism, rheumatoid factor*, anti-CCP*)Plain radiograph: calcification in regions of fibro- or hyaline cartilage+Plain radiograph: calcification of the synovial membrane/capsule/tendon+Conventional CT: calcification in regions of fibro- or hyaline cartilage+Conventional CT: calcification of the synovial membrane/capsule/tendon+Ultrasound: CPP crystal deposition in fibro- or hyaline cartilage+Ultrasound: CPP crystal deposition in synovial membrane/capsule/tendons+Dual-energy CT: CPP crystal deposition in fibro- or hyaline cartilage+Dual-energy CT: CPP crystal deposition in synovial membrane/capsule/tendon+

*Potential negative predictor +Assessed in the knee, wrist, and/or 1 additional affected joint

Disclosure of Interests:

Sara Tedeschi Consultant of: NGM Biopharmaceuticals, Tristan Pascart: None declared, Augustin Latourte Consultant of: Novartis, Cattleya Godsave: None declared, Burak Kundaki: None declared, Raymond Naden: None declared, William Taylor: None declared, Nicola Dalbeth Speakers bureau: Abbvie and Janssen, Consultant of: AstraZeneca, Dyve, Selecta, Horizon, Arthrosi, and Cello Health, Tuhina Neogi: None declared, Fernando Perez-Ruiz: None declared, Ann Rosenthal: None declared, Fabio Becce Consultant of: Horizon Therapeutics, Grant/research support from: Siemens Healthineers, Eliseo Pascual: None declared, Mariano Andrés: None declared, Thomas Bardin: None declared, Michael Doherty: None declared, Hang Korng Ea: None declared, Georgios Filippou: None declared, John FitzGerald: None declared, Marwin Gutierrez: None declared, Annamaria Iagnocco: None declared, Tim Jansen Speakers bureau: Abbvie, Amgen, BMS, Grunenthal, Olatec, Sanofi Genzyme, Consultant of: Abbvie, Amgen, BMS, Grunenthal, Olatec, Sanofi Genzyme, Minna Kohler Speakers bureau: Lilly, Consultant of: Novartis, Frederic Lioté: None declared, Mark Matza: None declared, Geraldine McCarthy Consultant of: PK Med, Roberta Ramonda: None declared, Anthony Reginato: None declared, Pascal Richette: None declared, Jasvinder Singh Speakers bureau: Simply Speaking, Consultant of: Crealta/Horizon, Medisys, Fidia, UBM LLC, Trio health, Medscape, WebMD, Adept Field Solutions, Clinical Care options, Clearview healthcare partners, Putnam associates, Focus forward, Navigant consulting, Spherix, Practice Point communications, Francisca Sivera: None declared, Alexander So: None declared, Lisa Stamp: None declared, Janeth Yinh: None declared, Chio Yokose: None declared, Robert Terkeltaub Consultant of: Sobi, Horizon Therapeutics, Astra-Zeneca, Selecta, Grant/research support from: Astra-Zeneca, Hyon Choi: None declared, Abhishek Abhishek Consultant of: NGM Biopharmaceuticals.

OP0317 ACCURACY OF THE OMERACT DEFINITIONS FOR IDENTIFICATION OF CALCIUM PYROPHOSPHATE CRYSTALS WITH ULTRASOUND: FINAL RESULTS OF THE OMERACT US IN CPPD SUB-TASK FORCE STUDY

Background:

The OMERACT Ultrasound (US) in calcium pyrophosphate deposition disease (CPPD) sub-task force has been working on the use of US in CPPD since 2014 first creating definitions for CPPD identification and then assessing the reliability[1].

Objectives:

Objective of this study is to assess the diagnostic accuracy (truth) of US in CPPD.

Methods:

Consecutive patients waiting to undergo knee replacement surgery due to osteoarthritis were enrolled in 12 centres from 6 countries. Each patient underwent US examination of the knee, focusing on the menisci and the hyaline cartilage, the day prior to surgery, scoring each site for presence/absence of CPP as defined previously[1]. After surgery, the menisci and the condyles were retrieved and examined microscopically. Six samples were collected, both from the surface and from the internal part of menisci and cartilage trying to cover a large part of it. All slides were observed under transmitted light microscopy and by compensated polarised microscopy. A dichotomous score was given for the presence/absence of CPP. US and microscopic analysis were performed by different operators, blind to each other’s findings. Sensitivity and specificity of US were calculated using microscopic findings as the gold standard.

Results:

101 patients have been enrolled in the study. 33 patients have been excluded due to loss of anatomical pieces at surgery. The mean age of the remaining 68 pts was 71yo (±8), 44 women, 34 were affected by CPPD according to microscopy. Overall and per site diagnostic US accuracy results are presented in table 1

Diagnostic accuracySensitivitySpecificityPositive Predictive valueNegative Predictive valueGlobal0.750.910.590.690.87Medial meniscus0.820.870.770.770.87Lateral meniscus0.750.830.680.680.83Medial cartilage0.860.790.920.880.85Lateral cartilage0.820.710.880.770.84Medial side (combined cartilage and meniscus)0.820.880.760.790.87Lateral side (combined cartilage and meniscus)0.780.880.690.730.86

Conclusion:

Our results demonstrate that US is an accurate exam for identification of CPPD. The best combination of sensitivity and specificity is achieved by examining the medial aspect of the knee.

References:

[1]Filippou G, Scirè CA, Adinolfi A,et al.Identification of calcium pyrophosphate deposition disease (CPPD) by ultrasound: reliability of the OMERACT definitions in an extended set of joints—an international multiobserver study by the OMERACT Calcium Pyrophosphate Deposition Disease Ultrasound Subtask Force.Ann Rheum Dis2018;:annrheumdis-2017-212542. doi:10.1136/annrheumdis-2017-212542

Disclosure of Interests:

Georgios Filippou: None declared, Anna Scanu: None declared, Antonella Adinolfi: None declared, Carmela Toscano: None declared, Dario Gambera: None declared, Raquel Largo: None declared, Esperanza Naredo: None declared, Emilio Calvo: None declared, Gabriel Herrero-Beaumont: None declared, Pascal Zufferey: None declared, Christel Madelaine-Bonjour: None declared, Daryl MacCarter: None declared, Stanley Makman: None declared, Zachary Weber: None declared, Fabiana Figus: None declared, Ingrid Möller: None declared, Marwin Gutierrez: None declared, Carlos Pineda: None declared, Denise Clavijo Cornejo: None declared, Héctor García: None declared, Victor Ilizaliturri: None declared, Jaime Mendoza Torres: None declared, Raul Pichardo: None declared, Luis Carlos Rodriguez Delgado: None declared, Emilio Filippucci Speakers bureau: Dr. Filippucci reports personal fees from AbbVie, personal fees from Bristol-Myers Squibb, personal fees from Celgene, personal fees from Roche, personal fees from Union Chimique Belge Pharma, personal fees from Pfizer, outside the submitted work., Edoardo Cipolletta: None declared, Teodora Serban: None declared, Catalin Cirstoiu: None declared, Florentin Ananu Vreju: None declared, Dun Grecu: None declared, Gael Mouterde: None declared, Marcello Govoni: None declared, Leonardo Punzi: None declared, Nemanja Damjanov Grant/research support from: from AbbVie, Pfizer, and Roche, Consultant of: AbbVie, Gedeon Richter, Merck, Novartis, Pfizer, and Roche, Speakers bureau: AbbVie, Gedeon Richter, Merck, Novartis, Pfizer, and Roche, Lene Terslev Speakers bureau: LT declares speakers fees from Roche, MSD, BMS, Pfizer, AbbVie, Novartis, and Janssen., Carlo Alberto Scirè: None declared, Annamaria Iagnocco Grant/research support from: Abbvie, MSD and Alfasigma, Consultant of: AbbVie, Abiogen, Alfasigma, Biogen, BMS, Celgene, Eli-Lilly, Janssen, MSD, Novartis, Sanofi and Sanofi Genzyme, Speakers bureau: AbbVie, Alfasigma, BMS, Eli-Lilly, Janssen, MSD, Novartis, Sanofi

The Italian Society of Rheumatology clinical practice guidelines for the diagnosis and management of gout

Gout is a chronic disease with an increased risk of premature death related to comorbidities. Treatment of gout has proved suboptimal and clinical practice guidelines (CPGs) are expected to have a key role in achieving improvement. Since new evidence has become available, the Italian Society for Rheumatology (SIR) has been prompted to update the 2013 recommendations on the diagnosis and management of gout. The framework of the Guidelines International Network Adaptation Working Group was adopted to identify, appraise (AGREE II), synthesize, and customize the existing gout CPGs to the needs of the Italian healthcare context. The task force consisting of rheumatologists from the SIR Epidemiology Unit and a committee with experience on gout identified key health questions to guide a systematic literature review. The target audience includes physicians and health professionals who manage gout in practice, and the target population includes adult patients suspected or diagnosed as having gout. These recommendations were finally rated by an external multi-disciplinary commission. From a systematic search in databases (Medline, Embase) and grey literature, 8 CPGs were selected and appraised by two independent raters. Combining evidence and statements from these CPGs and clinical expertise, 14 recommendations were developed and graded according to the level of evidence. The statements and potential impact on clinical practice were discussed and assessed. These revised recommendations are intended to provide guidance for the diagnosis and the treatment of gout and to disseminate the best evidence-based healthcare for this disease.

Spasmophilia and entrapment nerve syndrome comorbidities in fibromyalgic patients: a possible neuromuscular pain generator

This paper is aimed at investigating whether peripheral dysfunction at the neuromuscular level may represent a pain generator in fibromyalgia. We studied the prevalence of spasmophilia (SP), carpal tunnel syndrome (CTS) and ulnar neuropathy at the elbow (UNE) in a group of 40 subjects suffering from fibromyalgia. Clinical and electrophysiological data were obtained to ascertain whether comorbid conditions were present. For subjective evaluation of symptoms severity, validated questionnaires for CTS and UNE were completed by patients. Twenty subjects were positive for SP (50%); CTS was diagnosed in 12 subjects (30%); no patient suffered from UNE; 6 subjects were affected at the same time by SP and CTS (15%); 14 subjects (35%) were affected by SP alone. The prevalence of CTS and SP was higher in fibromyalgia subjects than in the general population. The scores of the questionnaires related to CTS were significantly higher in fibromyalgia subjects positive for CTS, with respect to the other subjects. In fibromyalgia, CTS and SP may be considered clinical entities in themselves, the importance of which lies in their acting as peripheral pain generators that enhance or initiate central sensitization, thereby contributing to chronic widespread pain. The amplification of pain is indeed a correctable/misguided message that occurs inside the brain of fibromyalgia subjects and identification and local treatment of pain generators would lessen the total pain burden. The magnitude of the overlap in symptoms between fibromyalgia and CTS/SP necessitates careful investigation of these conditions.

Ultrasound in the diagnosis of calcium pyrophosphate dihydrate deposition disease. A systematic literature review and a meta-analysis

OBJECTIVE

Ultrasonography (US) demonstrated to be a promising tool for the diagnosis of calcium pyrophosphate dihydrate deposition disease (CPPD). The aim of this systematic literature review (SLR) was to collect the definitions for the US elementary lesions and to summarize the available data about US diagnostic accuracy in CPPD.

METHODS

We systematically reviewed all the studies that considered US as the index test for CPPD diagnosis without restrictions about the reference test or that provided definitions about US identification of CPPD. Sensitivity and specificity were calculated for each study and definitions were extrapolated. Subgroup analyses were planned by anatomical site included in the index text and different reference standards.

RESULTS

Thirty-seven studies were included in this review. All the studies were eligible for the collection of US findings and all definitions were summarized. US description of elementary lesions appeared heterogeneous among the studies. Regarding US accuracy, 13 articles entered in the meta-analysis. Considering each joint structure, the sensitivity ranged between 0.77 (0.63-0.87) and 0.34 (0.16-0.58) while the specificity varies between 1.00 (0.89-1.00) and 0.92 (0.16-1.00). Considering the reference standards used, the sensibility ranged between 0.34 (0.02-0.65) and 0.87 (0.76-0.99) while specificity ranged between 0.84 (0.52-1.00) and 1.00 (0.99-1.00).

CONCLUSION

US is potentially a useful tool for the diagnosis of CPPD but universally accepted definitions and further testing are necessary in order to assess the role of the technique in the diagnostic process.

Change perspective to increase diagnostic accuracy of ultrasonography in calcium pyrophosphate dihydrate deposition disease! A new approach: the axial scan of the meniscus

Ultrasonography (US) is a relevant tool in the study of calcium pyrophosphate dihydrate (CPP) deposition disease. However, differential diagnosis of hyperechoic deposits within the fibrocartilage can be difficult; moreover, US study is limited by the need of an adequate acoustic window. We describe a US scanning technique that offers a new viewpoint in the study of knee meniscal structure: a longitudinal scan performed according to the long axis of meniscus. This technique proves to be particularly useful for the identification of CPP deposition, but could also improve the US diagnostic utility and accuracy in other meniscal pathologies.

Radiologists and rheumatologists on performing and reporting shoulder ultrasound: from disagreement to consensus

Shoulder pain is a common condition in the rheumatologist's practice, yet there are no guidelines on how to report shoulder ultrasound (US) examinations. The aim of this study was to compare scanning and reporting techniques performed by radiologists and rheumatologists and identify any discrepancies between the two. The participants in this study were five rheumatologists and two radiologists specialized in musculoskeletal US. The study was divided in 2 phases. In the first phase, each participant performed an US of 3 patients and reported the findings without knowing the patient diagnosis and the findings reported by the other operators. Other three investigators reported the US technique of each operator. Reports and images were subsequently compared to identify any discrepancies and reach consensus on a common approach. In the second phase, a US scan was performed on a fourth patient in a plenary session to assess feasibility and efficacy of the common approach The US scanning technique was similar for all operators. The differences in reporting emerged in the description of the rotator cuff disease. Radiologists provided a detailed description of lesions (measurements along 2 axis and scoring of lesions), whereas rheumatologists described carefully the inflammatory changes. The experts concluded that lesions should be measured along 2 axes and the grade of degeneration and the age of the lesion should be reported. Another difference emerged in the description of the irregularities of the bone surface. The experts concluded that the term erosion should be used only when an inflammatory joint disease is suspected. This study led to the clarification of some inconsistencies in US reporting, and represented an interesting collaborative experience between radiologists and rheumatologists.

Paget's disease

Paget's disease of bone is the most common metabolic bone disease after osteoporosis and affects 2-4% of adults over 55 years of age. Its etiology is only partly understood and includes both genetic and environmental factors. The disease may be asymptomatic and can be uncovered incidentally on x-ray or in biochemical tests performed for another condition. It can also manifest itself with bone pain, deformity, fracture or other complications. Paget's disease is diagnosed by x-rays and in general has very typical radiological features, but occasionally the clinical picture may be unusual and a differential diagnosis of sclerotic or lytic metastases needs to be considered. Plasma total alkaline phosphatase activity is the most clinically useful indicator of disease activity. It is elevated in most untreated patients, but may be within the normal range in patients with monostotic or limited disease. Bisphosphonate therapy is indicated for patients with symptoms and should also be considered in patients with disease sites that suggest a risk of complications, such as long bones, vertebrae or base of the skull. Orthopedic surgery in Paget's disease patients includes almost exclusively the correction of fractures and arthroplasty.

Prevalence of Baker's cyst in patients with knee pain: an ultrasonographic study

The objectives of this study are to investigate the prevalence of Baker's cyst (BC) in patients with knee pain, and to assess the correlation between BC and severity of osteophytes and joint effusion. A retrospective study was conducted on a group of patients with knee pain referred to our outpatient clinic for ultrasonography of the knee between January 2010 and February 2011. Patients underwent an ultrasonographic exam of the knees to assess the presence of marginal femorotibial osteophytosis, joint effusion and BC. A dichotomous score was assigned to each item (1 present, 0 absent) and severity of US signs of osteoarthritis and joint effusion were also graded semiquantitatively. Collected data were processed using logistic regression analysis to evaluate the correlation between degree of osteophytosis and joint effusion and BC. Patients affected by inflammatory joint conditions or with history of joint surgery or recent trauma were excluded. A total of 399 patients with knee pain were studied (299 women), in the age range 18-89 years (mean 56.2, SD 16.3 years). 293 patients (73.4%) showed sonographic features of osteoarthritis and 251 (62.9%) joint effusion. BC was found in 102 patients (25.8%) together with a positive association with sonographic features of osteoarthritis and joint effusion. Our data show a prevalence of BC of 25.8% in a population of patients with knee pain, and suggest that BC is positively related to osteoarthritis and joint effusion. Ultrasonographic examination of knee is worthwhile in patients with painful osteoarthritis or evidence of effusion.

Sucralfate gel as a radioprotector against radiation induced dermatitis in a hypo-fractionated schedule: a non-randomized study

External beam radiotherapy with high doses provokes many acute skin reactions, such as erythema and moist desquamation. Many topical preparations are used in radiation oncology departments in the skin care. Sucralfate humid gel, a colloidal physical form of the anti-ulcer drug sucralfate, promotes epithelial regeneration and activates cell proliferation. Based on this knowledge, we performed a non-randomized clinical trial to evaluate the efficacy of topical sucralfate gel in 30 breast cancer patients receiving postoperative accelerated hypofractionated photon beam therapy. The comparison was performed with 30 patients as historical controls. The acute reaction of the skin was significantly lower in the group receiving the sucralfate gel (p<0.05, Mann Whitney test), while 90% of the patients had no evidence of radiation induced skin toxicity. There was no sucralfate gel related toxicity reported by any patient in this study. More patients in a randomized way are needed for more definite results.

Diffusion and applications of musculoskeletal ultrasound in Italian Rheumatology Units

The Musculoskeletal Ultrasound Study Group of the Italian Society of Rheumatology (SIR) was founded during the 68th SIR Congress, on November 2011. The request of activation of this group was based on the increasing interest and the widespread diffusion of ultrasound in the scientific rheumatology community and on the solid experience of some Italian rheumatologists in the field. The aims of the Study Group are to stimulate the applications and use of ultrasound in the clinical practice at the level of the Italian rheumatology units and, in addition, to develop research projects at a national level...

Ultrasonography vs. clinical examination in children with suspected arthritis. Does it make sense to use poliarticular ultrasonographic screening?

OBJECTIVES

Juvenile idiopathic arthritis (JIA) is a term that encompasses all forms of arthritis that begin before the age of 16 years old, persist for more than 6 weeks and are of unknown cause. The ILAR criteria for JIA classification are based on the number of joints involved. The aim of our study was to compare clinical evaluation and ultrasonography (US) in the assessment of joint synovitis in children with suspected JIA.

METHODS

We enrolled in our study all children who presented at our outpatient clinic of Paediatric Rheumatology with suspected JIA. All the children underwent a clinical examination for joint swelling (40 joints), a tender joint count (42 joints) and US examination (42 joints) on the same day. They all returned to the clinic after approximately 2 weeks with the results of the tests prescribed at the first visit and a diagnosis was formulated.

RESULTS

Thirty-one children were enrolled. More synovitis was identified by US than by than clinical examination (42 joints vs. 27). Clinical examination classified as swollen 13 joints that did not result affected at US. Of the 94 painful joints, 24 were affected by synovitis at US. The final diagnoses were: 9 children with JIA (any form), 9 were classified as healthy and 13 with other diseases. One child was reclassified and 2 were diagnosed with JIA thanks to US.

CONCLUSIONS

US detected more synovitis than clinical examination in children with suspected JIA, therefore, US should be included in the screening procedure of children with suspected JIA.

Ulnar neuropathy at the elbow: how frequent is the idiopathic form? An ultrasonographic study in a cohort of patients

OBJECTIVE

Ulnar neuropathy at the elbow (UNE) is the second most frequent focal neuropathy of the arm. The aim of our study was to establish the frequency of anatomical changes of the cubital tunnel capable of causing UNE.

METHODS

Ninety-one consecutive patients affected by UNE, as established by neurophysiological studies, were enrolled in the study. All patients underwent ultrasonographic examination of the elbow, paying particular attention to the cubital tunnel, which was studied with either static or dynamic scans.

RESULT

Fifty-four of the 91 patients (59.3%) had at least one anatomical alteration of the cubital tunnel. The changes observed in our patients were: subluxation of the ulnar nerve (18.7%), luxation of the ulnar nerve (9.9%), presence of osteophytes (6.6%), presence of accessory muscle (8.8%), articular ganglion (1.1%), post-traumatic lesions (3.3%), presence of osseous fragment (1.1%).

CONCLUSIONS

A possible cause of ulnar nerve entrapment at the elbow was found in more than half of the patients. Joint ultrasonography is indispensable for the identification of such alterations as it allows for both static and dynamic evaluation of the ulnar nerve.

Heel fat pad involvement in rheumatoid arthritis and in spondyloarthropathies: an ultrasonographic study

BACKGROUND

Heel fat pad inflammation and degeneration have been frequently proved to cause talalgia. Painful heel fat pad is often confused with plantar fasciitis, and only magnetic resonance imaging (MRI) or ultrasonography (US) can differentiate these conditions. Scanty data are available about heel fat pad involvement in the course of chronic polyarthritis.

OBJECTIVE

To investigate with US the heel fat pad involvement in patients with rheumatoid arthritis (RA) and spondyloarthropathies (SpA); to describe and compare the clinical and sonographic features of this lesion in the two groups.

METHODS

The heels of 181 consecutive outpatients with RA and 160 with SpA were studied by US and radiography. A control group of 60 healthy subjects was examined by US.

RESULTS

Two different patterns of involvement of the heel fat pad were observed. The inflammatory-oedematous pattern was more frequent in patients with RA (6.6%) than in those with SpA (1.8%), and was associated with talalgia--even if it was not associated with plantar fasciitis or enthesophyte (bony spur). The degenerative-atrophic pattern was less frequent (1.1% in RA, 1.9% in SpA), and was associated with plantar fasciitis and subcalcaneal enthesophyte.

CONCLUSIONS

The inflammatory-oedematous lesion of the heel fat-pad is relatively frequent in RA and causes subcalcaneal pain. Degenerative-atrophic changes of the heel fat pad can be observed in RA and SpA, and seem to be associated with chronic abnormalities of the plantar fascia and of its enthesis.