Relationship between intraoperative neurophysiological monitoring alert and postoperative walking ability

Abstract

BACKGROUND: Intraoperative neurophysiological monitoring is popular in spinal surgery. However, a severe iatrogenic spinal cord injury cannot be completely eliminated. Is there a relationship between true positive intraoperative neurophysiological monitoring alert during particular surgical steps and postoperative neurological recovery? This topic is to improve the safety of spinal invasive procedures. OBJECTIVE: To determine the relationship between true positive intraoperative neurophysiological monitoring alert during particular surgical steps and postoperative walking ability. METHODS: A retrospective study of 2 249 patients undergoing intraoperative neurophysiological monitoring in Li Ka Shing Faculty of Medicine, the University of Hong Kong was conducted. Standard patient demographics, diagnosis and operative features and intraoperative neurophysiological monitoring data were collected. There were 10 cases of true positive intraoperative neurophysiological monitoring alert (4 males, 6 females, 14-88 years old), and the average follow-up time was 9.8 years. The patients were divided into two groups based on whether surgical steps triggering intraoperative neurophysiological monitoring alert impact the spinal cord or not. The study was performed in accordance with the ethical requirements of Li Ka Shing Faculty of Medicine, the University of Hong Kong, and the patients and their guardians signed the informed consents. RESULTS AND CONCLUSION: These alerts occurred during decompression (n=3), anterior disc release (n=1), finding the entering point of T3 pedicle (n= 1), screw insertion (n=1), reduction of fracture (n=2), insertion of wire (n= 1), and cement injection (n=1). Among these patients, 100% of spinal cord invasive procedure patients developed incompetence of walking, while 80% (4/5) of spine cord non-invasive patients were capable of walking (P < 0.05). After the alert was triggered, four patients continued with primary program, three patients underwent expanding decompression and three patients gave up surgery. If true positive intraoperative neurophysiological monitoring alert is reported during spinal invasive procedures, there should be a very high chance of postoperative walking disability. If any conditions occur, the surgery needs to be stopped, and instead, remedial measures such as surgery suspension, steroids injection, and additional decompression should be performed immediately.