For more than 60 years intra-articular an peri-articular injection are part of the standard treatment of arthritis. In vast majority of interventions needles used to be guided by anatomical landmarks as orientation (“blind” join injection). However, studies of the accuracy of “blind” injections into various joints showed that about two thirds of knee and ankle injections and only half of the wrist injections were intra-articular. The accuracy of blind corticosteroid injections into the glenohumeral joint is also questionable. Tobola et al. found the accuracy of an anterior approach glenohumeral injection was 64.7%, regardless of clinician experience. Utilizing the additional measure of ultrasound or another image modality to guide injections improves accuracy. In comparison to a blind posterior injection technique, ultrasound guided injections had a greater success rate of reaching of the glenohumeral joint (72.5% vs. 92.5%. Musculoskeletal ultrasound (MSUS) allows the possibility of reliable guidance of needle during diagnostic (e.g. needle aspiration of synovial liquid for analysis) and treatment interventions (e.g., intra-articular injections of drugs). Ultrasound guidance enables the exact placement of the needle into the structure of interest and accurate injection of medication. Moreover, it helps in establishing more precise diagnosis and in confirmation of the indication for injection. Ability of ultrasound guided injections to improve clinical outcomes compared to that of palpation guided injections however remains unclear. Lee et al. compared ultrasound-guided injections of triamcinolone with blind injections. At 6 weeks, the ultrasound guided injection group did not have statistically superior improvements than blind injections in flexion, abduction, external rotation or internal rotation, although improvements from baseline were significant within both groups (p<0.001). The ultrasound guided injection group also did not have significantly better VAS score improvements after 3 weeks. On the contrary, one study showed that US guidance significantly improved the outcome of intra-articular steroid injections compared with anatomical palpation guidance. For successful implementation of ultrasound-guided injection technique appropriate training is required. After successful training, guidance of needle allows precise and successful diagnostic and/or treatment intervention. Moreover, ultrasound examination can visualize different tissues which could be damaged by the needle during the “blind” injection. Ultrasound visualization allows examiner to minimize possible damage of blood vessels, nerves, tendons, ligaments, cartilage and other tissues by the needle. Two main advantages of ultrasound-guided injections are increased accuracy and minimal risk of adverse events during and after the intervention.
Disclosure of Interest None declared