Ultrasound guided versus conventional joint and soft tissue fluid aspiration in rheumatology practice: a pilot study.

Objective: To compare joint and soft tissue aspiration using a conventional technique with an ultrasound (US) guided technique.

Methods: In the conventional group, 32 joints in 30 consecutive patients referred for joint aspiration and injection to an experienced consultant rheumatologist were aspirated. In the US guided group, 31 consecutive patients were examined by US to confirm the presence and location of fluid. Following US examination, aspiration was performed by a second rheumatologist based on the US localization of fluid or under direct US guidance.

Results: In the conventional group, successful aspiration was achieved in 10 (32%) joints. In the US guided group, successful aspiration was achieved in 31 (97%) joints. The mean volume of fluid obtained from successful aspirations was similar in both groups (11.7 ml in the US group and 14 ml in the conventional group).

Conclusion: The use of US to localize joint and soft tissue fluid collection greatly improves the rate of diagnostic synovial fluid aspiration, particularly in small joints. This has important implications for accurate administration of local steroid therapy and emphasizes the importance of US as a useful tool in clinical rheumatological practice.