Synovitis of small joints: sonographic guided diagnostic and therapeutic approach.

OBJECTIVE: The aim of this pictorial essay is to describe the sonographic guided approach to investigation and local injection therapy of a small joint in a patient with psoriatic arthritis (PA).

METHODS: Sonographic pictures are obtained using a high frequency ultrasonography apparatus equipped with a 13-MHz transducer.

RESULTS: Ultrasonography allows a careful morphostructural assessment of soft tissue involvement in PA patients. Sonographic findings include joint cavity widening, capsular thickening, synovial proliferation, synovial fluid changes, tendon sheath widening. Ultrasound guided placement of the needle within the joint and injection of corticosteroid under sonographic control can be easily performed.

CONCLUSIONS: High frequency ultrasonography is a quick and safe procedure that allows a useful diagnostic and therapeutic approach in patients with arthritis of small joints.