Ultrasound of the upper limb: when to use it in athletes.

Ultrasound is a powerful screening examination for athletes with upper limb injuries. It is very effective in demonstrating injuries to muscle, tendon, ligament, and nerves. The technique is particularly useful in excluding joint effusion and in detecting soft tissue foreign bodies. Dynamic ultrasound examination is especially useful in detecting subluxation of tendon and nerves; it may be the only means of demonstrating the cause of snapping. Detailed anatomical knowledge is mandatory, and the examination should be structured and systematic. Ultrasound may overlook disorders of the deep structures in joints and bone disease. Those employing the technique must understand the strengths of ultrasound examination compared with and in combination with MRI.