Guidance by ultrasound of intra-articular injections in the knee and hip joints

Objective: To develop and assess a stable method for ascertaining the place ment of intraarticular injections for osteoarthritis (OA) in the hip and kn ee. Methods: Injections into the hip or knee joint with e.g. hyaluaronan or cor tisone were performed under the guidance of ultrasound. For this purpose an Acuson Sequoia apparatus and a 8-15 MHz transducer were used. After perfor ation of the capsule with a 21 G needle, 0.5-1 ml of asmospheric air and 1 ml lidocain 1% was injected with simultaneous recording of the ultrasound s ignals. This procedure was undertaken before the injection of the medicatio n through the in situ needle. Results: In the hip joint the injected air could readily ascertain the plac ement of the injection with a sharp echoic contrast forming on the ultrasou nd picture respecting the joint cavity. In the knee joint the procedure gav e the best results in joints which have a small amount of fluid in either t he suprapatellar bursa or in a pouch regularly observed over the lateral jo int margin. However, also in some so-called 'dry' knee joints the air could be traced in the bursa by ultrasound. Conclusion: By the injection of air, it is possible to test the placement o f intraarticular injections in both hip and knee joints. This procedure wil l give a supplementary documentation of the injection as compared to a mere ultrasonographic demonstration of the position of the needle in the joint. The method is proposed as a tool for both learning purposes and quality as surance in daily therapy. (C) 2001 OsteoArthritis Research Society Internat ional.