Benefits of ultrasonography in the management of early arthritis: a cross-sectional study of baseline data from the ESPOIR cohort.

Objective: To assess ultrasonography's (US) performance to detect the structural damage in the initial evaluation of early arthritis (EA) using the Etude et Suivides Polyarthrites Indifférenciées Récentes (ESPOIR) cohort.

Methods: ESPOIR is a French, multi-centric EA cohort. Four centres assessed the structural damage by both X-ray and US examination at baseline.