Entheses ultrasound assessment in primary Sjogren's syndrome

Musculoskeletal pain is a common complaint among patients with primary Sjogren's syndrome (pSS). Joints clinical examination is oftenly normal. A periarticular origin of this pain may be possible. Since clinical examination lacks sensitivity and precision, the use of musculoskeletal ultrasound (US) is more interesting in the evaluation of the entheses involvement, as it is shown to be a more sensitive tool. Our objective was to assess, by an ultrasonographic study, the entheses involvement in the widespread pain of patients with pSS.

This is a prospective study including 25 women with pSS and 25 age and sex matched healthy controls. An ultrasound examination, using grey scale and Doppler US, of five enthesitic sites (distal quadricipital, proximal patellar, distal patellar, distal Achillian and distal brachial tricipital) sought bilaterally the following lesions: hypoechogenicity, thickening, loss of fibrillar structure, erosions, enthesophytes, calcifications or Doppler hypervascularisation. A final score was calculated by summing the abnormalities scores of all entheses.

The mean age was 53.2±11.3 years in the pSS group and 50.6±9.7 years in the control group. The mean number of pathological entheses on ultrasound was 3.92±1.93 in the pSS group versus 4.52±2.27 in the control group (P>0.05). The total score for enthesitis abnormalities was 4.96±2.59 versus 5.72±2.92 (P>0.05), respectively. There was a positive correlation between total score of ultrasound enthesitic abnormalities and age in both groups.

In patients with pSS, clinically painful sites were more frequently found than in US. Musculoskeletal pain was not due to enthesitis.