Ultrasonography for the assessment of enthesitis in psoriatic arthritis: systematic review with meta-analysis.

OBJECTIVES

The specificity of US for enthesitis in PsA is unclear. The objective was to analyse the specificity of US enthesitis in Mode B and using power Doppler for the diagnosis of PsA through a systematic review with meta-analysis.

METHODS

Systematic review in PubMed 2010 to June 2023 of studies of adult patients with confirmed PsA with or without a control group of non-PsA patients, reporting information on US enthesitis. Data were analysed on (i) the prevalence of US enthesitis (presence of at least one enthesitis) in PsA patients and non-PsA patients, (ii) specificity and sensitivity of US enthesitis and then specifically power Doppler for PsA diagnosis and (iii) most specific localizations of enthesitis in PsA patients. Pooled percentages and means were evaluated using univariate random effects meta-analysis.

RESULTS

In 76 articles, 5927 patients with PsA were compared with 3423 controls (59.0% of whom had psoriasis). The prevalence of US enthesitis was 73.7% (95% CI 56.6-90.9%) in PsA patients vs 12.6% (2.6-22.3%) in controls. The pooled specificity and sensitivity of Mode B US were 73.2% (59.3-87.0%) and 62.1% (47.9-76.4%); and of power Doppler, were 97.9% (96.5-99.5%) and 14.7% (8.2-21.2%), respectively. The site most frequently involved in PsA but not in controls was the Achilles tendon, in which erosions and power Doppler activity were most discriminant.

CONCLUSION

In this systematic review, US enthesitis was highly prevalent in PsA patients. Evidencing enthesitis by US was found to be reasonably specific and could contribute to the diagnosis of PsA; power Doppler was highly specific, however it was rarely present.