[The elbow: normal and pathologic patterns].

The elbow is an anatomically complex joint, which is nonetheless quite easy to investigate by means of US thanks to the superficial location and relative abundance of periarticular structures--i.e., tendons, muscles, bursae, vessels and nerve. Thus, US allows lateral, medial, anterior and posterior musculo-tendinous joints to be demonstrated, together with vasculonervous structures--i.e., arteries, veins, nerves. Linear or convex US probes (at 7.5 or 10 MHz) are employed. The examination must be performed with either a flexed or an extended elbow. US shows typical patterns in traumas (joint and periarticular conditions), in degenerative disorders (chondromatosis), inflammations (epicondylitis, bursitis, hygromas, rheumatoid nodules and joint effusions) and finally in tumors. The US patterns of the above conditions are quite typical and often allow a diagnosis to be made. Therefore, US proves to be a reliable first-choice technique in the evaluation of the periskeletal elbow.