The relationship between ultrasound and physical examination in the assessment of enthesitis in SpA patients: results from the DEUS multicentre study

OBJECTIVES: i) To explore the agreement between the OMERACT ultrasound lesions of enthesitis and physical examination in assessing enthesitis in spondyloarthritis (SpA) patients; ii) To investigate the prevalence and clinical relevance of subclinical enthesitis in this population. METHODS: Twenty rheumatology centres participated in this cross-sectional study. SpA patients, including axial SpA (axSpA) and psoriatic arthritis (PsA) patients, underwent both ultrasound scan and physical examination of large lower limb entheses. The OMERACT ultrasound lesions of enthesitis were considered, along with a recently proposed definition for 'active enthesitis' by our group. Subclinical enthesitis was defined as the presence of 'active enthesitis' in ≥1 enthesis in SpA patients without clinical enthesitis (i.e., number of positive entheses on physical examination and Leeds Enthesitis Index score =0). RESULTS: 4130 entheses in 413 SpA patients (224 axSpA/189 PsA) were evaluated through ultrasound and physical examination. Agreement between ultrasound and physical examination ranged from moderate (i.e., enthesophytes) to almost perfect (i.e., power Doppler and 'active enthesitis'). Patellar tendon entheses demonstrated the highest agreement, whereas Achilles tendon insertion showed the lowest. Among 158/413 (38.3%) SpA patients with clinical enthesitis, 108 (68.4%) exhibited no 'active enthesitis' on ultrasound. Conversely, of those 255 without clinical enthesitis, 39 (15.3%) showed subclinical enthesitis. Subclinical enthesitis was strongly associated with local structural damage. However, no differences were observed regarding the demographic and clinical profiles of SpA patients with and without subclinical enthesitis. CONCLUSIONS: Our study underscores the need for a comprehensive tool integrating ultrasound and physical examination for assessing enthesitis in SpA patients.

Power Doppler signal at the enthesis and bone erosions are the most discriminative OMERACT ultrasound lesions for SpA: results from the DEUS (Defining Enthesitis on Ultrasound in Spondyloarthritis) multicentre study.

OBJECTIVES: To assess, in spondyloarthritis (SpA), the discriminative value of the Outcome Measures in Rheumatology (OMERACT) ultrasound lesions of enthesitis and their associations with clinical features in this population. METHODS: In this multicentre study involving 20 rheumatology centres, clinical and ultrasound examinations of the lower limb large entheses were performed in 413 patients with SpA (axial SpA and psoriatic arthritis) and 282 disease controls (osteoarthritis and fibromyalgia). 'Active enthesitis' was defined as (1) power Doppler (PD) at the enthesis grade ≥1 plus entheseal thickening and/or hypoechoic areas, or (2) PD grade >1 (independent of the presence of entheseal thickening and/or hypoechoic areas). RESULTS: In the univariate analysis, all OMERACT lesions except enthesophytes/calcifications showed a significant association with SpA. PD (OR=8.77, 95% CI 4.40 to 19.20, p<0.001) and bone erosions (OR=4.75, 95% CI 2.43 to 10.10, p<0.001) retained this association in the multivariate analysis. Among the lower limb entheses, only the Achilles tendon was significantly associated with SpA (OR=1.93, 95% CI 1.30 to 2.88, p<0.001) in the multivariate analyses. Active enthesitis showed a significant association with SpA (OR=9.20, 95% CI 4.21 to 23.20, p<0.001), and unlike the individual OMERACT ultrasound lesions it was consistently associated with most clinical measures of SpA disease activity and severity in the regression analyses. CONCLUSIONS: This large multicentre study assessed the value of different ultrasound findings of enthesitis in SpA, identifying the most discriminative ultrasound lesions and entheseal sites for SpA. Ultrasound could differentiate between SpA-related enthesitis and other forms of entheseal pathology (ie, mechanical enthesitis), thus improving the assessment of entheseal involvement in SpA.

Reliability assessment of the definition of ultrasound enthesitis in SpA: results of a large, multicentre, international, web-based study.

OBJECTIVES: To investigate the reliability of the OMERACT US Task Force definition of US enthesitis in SpA. METHODS: In this web exercise, based on the evaluation of 101 images and 39 clips of the main entheses of the lower limbs, the elementary components included in the OMERACT definition of US enthesitis in SpA (hypoechoic areas, entheseal thickening, power Doppler signal at the enthesis, enthesophytes/calcifications, bone erosions) were assessed by 47 rheumatologists from 37 rheumatology centres in 15 countries. Inter- and intra-observer reliability of the US components of enthesitis was calculated using Light's kappa, Cohen's kappa, Prevalence And Bias Adjusted Kappa (PABAK) and their 95% CIs. RESULTS: Bone erosions and power Doppler signal at the enthesis showed the highest overall inter-reliability [Light's kappa: 0.77 (0.76-0.78), 0.72 (0.71-0.73), respectively; PABAK: 0.86 (0.86-0.87), 0.73 (0.73-0.74), respectively], followed by enthesophytes/calcifications [Light's kappa: 0.65 (0.64-0.65), PABAK: 0.67 (0.67-0.68)]. This was moderate for entheseal thickening [Light's kappa: 0.41 (0.41-0.42), PABAK: 0.41 (0.40-0.42)], and fair for hypoechoic areas [Light's kappa: 0.37 (0.36-0.38); PABAK: 0.37 (0.37-0.38)]. A similar trend was observed in the intra-reliability exercise, although this was characterized by an overall higher degree of reliability for all US elementary components compared with the inter-observer evaluation. CONCLUSIONS: The results of this multicentre, international, web-based study show a good reliability of the OMERACT US definition of bone erosions, power Doppler signal at the enthesis and enthesophytes/calcifications. The low reliability of entheseal thickening and hypoechoic areas raises questions about the opportunity to revise the definition of these two major components for the US diagnosis of enthesitis.

The role of ultrasonography in assessing disease activity in patients with rheumatoid arthritis and associated fibromyalgia.

AIM: The purpose of this study is to compare and correlate US evaluation with clinical scores of the disease activity in patients with rheumatoid arthritis (RA) and concomitant fibromyalgia (FM). MATERIAL AND METHODS: Ten patients diagnosed with RA according to the 2010 ACR/EULAR classification criteria and associated FM based on the ACR 1990 classification criteria and two control groups, one with RA (10 patients) and one with FM (10 patients), were included. Clinical assessment was performed and the disease activity scores were calculated. Synovial/tenosynovial hypertrophy, fluid collections in grey scale (GS), and Power Doppler (PD) US assessed by US in the 28 joints included in the disease activity score 28 (DAS28). RESULTS: GS US score and PD US scores were correlated with DAS28 only in patients with RA (Pearson r coefficients 0.3 and 0.5). Mean DAS28 score was significantly higher in the RA/FM group, compared to RA and FM (5.6 versus 4.6 versus 4.5, respectively). Patients with RA/FM had similar median US scores to RA patients, while in FM group significantly lower median US scores were detected (16 versus 9.5 versus 0 for GS US and 3.5 versus 1.5 versus 0 for PD US, respectively). CONCLUSIONS: Disease activity scores should be interpreted with caution in patients with RA and FM. When available, US should be used to guide treatment decisions in patients with RA and FM.

Bone erosions in rheumatoid arthritis: ultrasound findings in the early stage of the disease.

OBJECTIVE: The objective of this study was to determine the prevalence and distribution of bone erosions detectable by US in patients with early RA (ERA) in comparison with long-standing RA (LSRA), other erosive diseases and healthy controls. METHODS: Thirty patients with ERA and 80 patients with LSRA were consecutively recruited. Thirty patients with PsA, 15 with primary OA, 10 with gout and 20 healthy subjects were included as controls. Bone erosions were investigated at the following anatomical sites: the second and fifth metacarpal heads, the ulnar head and the first and fifth metatarsal heads, bilaterally. Dorsal, volar and lateral aspects were explored on longitudinal and transverse views. RESULTS: At least one US bone erosion was found in 20 (66.7%) of 30 patients with ERA and in 10 (33%) of them it was found on the fifth metatarsal head. Bone erosions were most frequently found on the lateral quadrants of all scanned anatomical sites. If the second and fifth metacarpal heads and the fifth metatarsal head were scanned, an erosive disease could be found in 60% of ERA patients. The first metatarsal head was most frequently involved in the disease control group. CONCLUSION: This study found a high percentage of ERA patients with US bone erosions, with the fifth metatarsal head and the lateral aspects the most frequently involved site and quadrants. US scanning for bone erosions on a few target joints was found feasible and provided information not obtainable with clinical examination.