Sonography of orthopedic hardware impingement of the extremities.

The purpose of this pictorial essay is to describe the sonographic appearance of orthopedic hardware impingement of the extremities. Sonography is not limited by metallic artifacts, can show the orthopedic hardware, and can be used to assess damage of adjacent soft tissues, including tendons, synovial bursas, muscles, nerves, and vessels. Its dynamic capabilities permit assessment of orthopedic hardware impingement present only in certain joint positions, during muscle contractions, and during tendon movements. Local pain elicited with application of pressure from the transducer confirms the diagnosis. Sonographically guided injections of steroid-anesthetic mixtures have both diagnostic and therapeutic effects.