MRI of the postoperative shoulder.

Performing and interpreting MRI of the shoulder in patients after surgery is a difficult task. The normal anatomic features are distorted by the surgical alterations as well as the artifacts that result from metal and other materials used in the surgical procedures. This article reviews the common surgical procedures undertaken in patients with rotator cuff disease and shoulder instability, and how they affect the appearance of the relevant anatomic structures on MRI examination. It also reviews the more common causes for residual and recurrent abnormalities seen in such patients and how MRI can be used to diagnose such lesions, thus aiding the orthopedic surgeon in treating these difficult clinical problems.