E228 www.spinejournal.com February 2014 CASE REPORT SPINE Volume 39, Number 3, pp E228-E230 ©2014, Lippincott Williams & Wilkins A Rare Cause of Postoperative Paraplegia in Minimally Invasive Spine Surgery Timothy Chung, MBBS,* Christopher Thien, FRACS,* and Yi Yuen Wang, MD*† DOI: 10.1097/BRS.0000000000000092 Study Design. A case report. Objective. To present a patient who underwent a minimally invasive transforaminal lumbar interbody fusion who postoperatively developed paraplegia as a rare complication of a Kirschner wire (K-wire). Summary of Background Data. The few complications of K-wires that have been reported include, dural tears and damage to intra-abdominal structures. Methods. A case report of a rare complication of a K-wire is reported and the relevant literature was then reviewed. Results. An 85-year-old female with an anterolisthesis at L4–L5 underwent a minimally invasive transforaminal lumbar interbody fusion. Postoperatively she developed paraplegia. A subdural hematoma from T12 to the sacrum was found and evacuated. It is proposed that this rare complication is a result of a K-wire. Conclusion. Care must be taken with the use of K-wires and additional measures should be carried out such as the marking of its position and radiological confirmation of depth. Key words: transforaminal lumbar interbody fusion, minimally invasive surgery, Kirschner wire, postoperative complication, anterolisthesis, canal stenosis, hematoma, paraplegia. Level of Evidence: 5 Spine 2014;39:E228–E230 From the *Department of Neurosurgery, St Vincent’s Hospital, Victoria, Australia; and †Department of Surgery, the University of Melbourne, St Vincent’s Hospital, Victoria, Australia. Acknowledgment date: May 9, 2013. First revision date: August 19, 2013. Second revision date: October 4, 2013. Acceptance date: October 14, 2013. The manuscript submitted does not contain information about medical device(s)/drug(s). No funds were received in support of this work. No relevant financial activities outside the submitted work. Address correspondence and reprint requests to Timothy Chung, MBBS, Department of Neurosurgery, St Vincent’s Hospital, 41 Victoria Parade, Fitzroy, Victoria 3065, Australia; E-mail: tjchung@me.com Computed tomography and magnetic resonance imaging demonstrated a grade 1 anterolisthesis at L4–L5 with severe canal and foraminal stenosis (Figure 1). A minimally invasive L4–L5 transforaminal lumbar interbody fusion (MIS-TLIF) was planned. The surgery proceeded uneventfully. Percutaneous pedicle screws were placed using 2-dimensional image intensifier guidance with sequential placement of pedicular Kirschner wires (K-wires), taps, and screws. A bilateral laminectomy from a unilateral approach was achieved and a 9-mm inter- body TLIF cage placed through a tubular retractor system. Intraoperatively, a single K-wire at right L4 was replaced after inadvertent removal on placement of dilators. There were no apparent complications, and somatosensory and motor evoked potentials were normal (Figure 2). The patient awoke with normal lower limb sensation and power; however, while in recovery, developed numbness from the level of T12 and weakness from the L1 myotome distally. Urgent magnetic resonance imaging demonstrated a large T2 hyperdense collection within the vertebral canal extending from approximately T12 to S1 suggestive of a postoperative epidural hematoma (Figure 3). The patient was immediately returned to theatre for an open laminectomy from L2 to L4 and evacuation of hematoma. Intraoperatively, a significant epidural hematoma was not encountered. The thecal sac however was noted to be tense and discolored. Opening of the thecal sac revealed an acute subdural hematoma that was evacuated using gentle suction and the passage of an infant feeding tube in a craniocaudal direction. DISCUSSION First described by Foley et al in 2003, 1 MIS-TLIF surgery has gained popularity as a method of lumbar arthrodesis. By min- imizing paraspinous tissue trauma, 2 the advantages of a mini- mally invasive approach compared with an open approach include decreased intraoperative blood loss, postoperative pain, and duration of hospital stay. 1,3–6 However, MIS-TLIF is not without its own unique diffi- culties and complications. Because of the minimally invasive approach, visualization of spinal structures is decreased and thus one needs to be able to comprehend 3-dimensional spinal anatomy from 2-dimensional radiographical images. Com- pared with an open TLIF or a posterior lumbar interbody fusion, MIS-TLIF is associated with a steeper learning curve. 6 CASE REPORT An 85-year-old female with a past history of ischemic heart disease and hypertension presented with a 12-month history of right sided sciatica having failed conservative measures. Relevant medications included aspirin that was ceased 7 days prior to surgery. Copyright © 2014 Lippincott Williams & Wilkins. Unauthorized reproduction of this article is prohibited.