Forgotten Kirschner wire passing across the sigmoid colon.

The Kirschner wire (K-wire) is used in the treatment of hip fractures, and migration of a K-wire into the pelvis with resultant colon injury is a very rare complication. We report a case in which a forgotten K-wire passing across the sigmoid colon was accidentally found by screening colonoscopy in a patient with no abdominal symptoms. Surgery was performed to remove the K-wire. Although the migration of a K-wire is extremely rare, it is important for it to be considered in patients with a history of orthopedic surgery.