Interventional ultrasound: a critical overview on ultrasound-guided injections and biopsies.

Over the last decades ultrasound-guided procedures have become increasingly diffused in rheumatology, mainly thanks to the technical advances achieved in the ultrasound (US) field, combined with the greater availability, good portability and reduced cost of US devices, compared to other imaging techniques already used in rheumatology units. The direct visualisation of the tissue under analysis and the real-time imaging performance enabled by US-guidance account for an improved accuracy and directness in needle placement in a number of rheumatology interventions such as tendon and intra-articular injections. Compared with blind procedures, US-guided injections are more accurate and safe and they result in better clinical outcome in terms of joints improvement in function and decreased risk of damages caused by needle misplacement. The accuracy in needle placement of US-guided injections has proven to be important not only in common intra-articular injections, but especially in case of complex anatomical areas like the hip, facet and atlanto-occipital joints, where blinded injections are deemed poorly accurate and thus highly risky. Moreover US guidance can be successfully employed in more complex procedures such as synovial biopsy, portal establishment or arthroscopy, where US can also be combined with other imaging techniques. Overall the employment of US-guided procedures is considered to be safe and well-tolerated, and increases the accuracy and therapeutic effectiveness of the interventions performed. This may pave the way for a more widespread employment of US-guidance in rheumatology units, and new studies could further explore the therapeutic advantages of these procedures.