Ultrasound-guided injection in osteoarticular pathologies: general principles and precautions.

In the past, needle aspirations or injections involving the motor system were always carried out either blind or guided by fluoroscopy. Over the last few years, sonography has begun to offer an interesting alternative. Its advantages are that it is a relatively inexpensive technique, while not emitting ionising radiation and being easily accessible. There has been a great deal of technical progress including high frequency transducers, which have led to performance improvements in terms of both diagnosis and treatment of pathologies of the motor system. Due to these technical advances and to sterile covers for the transducers, it is now possible to visualise and to aspirate or inject into a peripheral joint, a tendon sheath or a bursa with or without effusion. This technique does not require a contrast medium injection because the needle position can be checked directly. Minimally invasive, it allows a number of interventions to be carried out with a very low complication rate since the entire path of the needle is followed using sonography, which means that nerves, vessels and other structures can be avoided because they are visualised directly in real time.