IMPORTANCE: Wrong-level spine surgery (WLSS), a medical error in which a surgeon operates at an unintended vertebral level, is considered a "never event." However, it continues to be a problem in spine surgery today despite the implementation of preventive measures such as the Universal Protocol. The consequences of this event are severe for both the afflicted patient and the treating physician and may result not only in physical harm but also in costly medicolegal proceedings. OBSERVATIONS: While WLSS incidence varies with the patient population and practice setting, large studies generally report rates below 1%. Given the ubiquity of spine surgery, this remains a concerning number. Risk factors for WLSS can be categorized into three domains: patient factors, imaging issues, and technical issues. Awareness of risk factors allows surgeons to plan for difficulties in level localization. Many techniques for preventing WLSS have been developed, including invasive preoperative marking strategies. Intraoperative radiography or fluoroscopy is necessary but not sufficient for WLSS prevention, in that many errors occur after imaging. The evidence for prevention methods remains of low quality, necessitating future prospective comparison studies. CONCLUSIONS AND RELEVANCE: Consensus has been reached in professional societies: All spine surgeons should implement WLSS prevention protocols. We assess the reported techniques for safer surgery and emphasize one crucial time-out element: the time-out for level localization (TOLL). Addressing WLSS as a problem specific to spine surgery, we show that by using specially tailored prevention strategies, such measures will allow WLSS to become a true never event.
