Complications of spinal instrumentation.

Despite tremendous technical advances in spine surgery in recent decades, patients may experience residual or recurrent pain and other symptoms after such surgery. The standard history and physical examination have only limited utility for assessing the postoperative anatomy, and radiologists can play an important role in diagnosing complications and guiding postoperative care. To do so effectively, they must be familiar with the imaging features of successful and unsuccessful fusion, instrumentation fracture and loosening, complications due to faulty hardware placement, and postoperative infection. A basic knowledge of spinal biomechanics and common approaches to surgical instrumentation also may help radiologists anticipate and identify complications.