Migration of a Kirschner wire into the spinal cord: A case report and literature review

Context: A Kirschner wire (K-wire) is a stainless steel pin with at least one sharpened tip that is mainly used for the internal fixation of bone fractures. While some cases of K-wire dislocation and migration have been reported as complications after fracture surgery, the intraspinal migration of a K-wire is rare. Herein, we report a case in which a K-wire used for sternal fixation 7 years earlier migrated into the spinal canal. Findings: A 68-year-old male suddenly sustained severe radiating pain and numbness in his left upper extremity, and walked to our hospital. He had mild weakness in the left wrist extensor muscles and the left extensor digitorum. CT-myelography revealed a K-wire penetrating into the spinal cord at C5-6. There was no injury of the trachea, esophagus, or blood vessels. The patient had a history of surgical infection after cardiovascular surgery seven years before, and had undergone surgical debridement and sternum fixation with two K-wires. One K-wire had broken, and part of it migrated upward. Using an anterior approach, we detected the tip of K-wire below the left sternocleidomastoid muscle. We cut the K-wire into 1 to 2-cm pieces and removed it piece by piece. His postoperative course was uneventful and the symptoms improved markedly after the surgery. Conclusion: This is the first report of a K-wire that had been used for sternal fixation migrating into the spinal cord. This case illustrates that although rare, it is possible for a K-wire to migrate upward after sternal fixation.