Clinico-radiological correlation of enthesitis in seronegative spondyloarthropathies (SNSA)

The goal of this work was to evaluate clinico-radiological correlation of enthesitis in SNSA patients, selected for presenting at least one radiological enthesopathy. Out of 50 patients with SNSA, 40 were selected for having had at least one radiological enthesitis. In a cross-sectional study, 32 males and 8 females, whose mean age was 40.4 years and mean disease duration 13 years, were evaluated. Nineteen patients had ankylosing spondylitis, 15 psoriatic arthritis and 6 Reiter's syndrome. Sites evaluated were pelvis and lower limbs. Radiological enthesopathies were identified by the presence of calcifications, new bone formation and/or erosions in tendinous and ligamentous insertion sites, and clinical enthesitis due to pain or tenderness and/or swelling at such locations. The site most commonly involved radiologically was the sciatic tuberosity in 33/40 cases, followed by the calcaneus with 12/40 on its inferior and 11/40 on its posterior aspect. Fifteen patients (37%) presented clinical manifestations at tendinous insertion sites, but clinico-radiological correlation was found in only 4 (22%). We conclude that clinical and radiological manifestations correlate poorly in SNSA enthesitis, perhaps due to the wide diversity of developmental stages of the disease.