Introduction: Wrong level spine surgery is a significant problem for both patients and surgeons. Although it has a low incidence of between 1 in 2222 and 1 in 3010, 50% or more of spine surgeons will perform a wrong level spine surgery at some point in their careers. In a third of these cases, preoperative imagining is used but fails to detect the wrong level. Therefore, better detection methods are needed with which to verify surgeons’ clinical judgment.

Methods: Using historical data from prospective, pre-clinical, and clinical cases, we sought to test the efficacy of a proposed wrong level detection approach. Our approach involved pairing each preoperative x-ray with imaging of four nearby levels to see if any of these represent a better match than the surgeon’s hypothesized correct level. The ability of four different Detector Methods was analyzed in terms of their ability to identify the correct level. The dataset included 310 measurements from 46 unique cases.

Results: Data were analyzed using a hierarchical regression approach to test Detector Methods One, Two, Three, and Four. At a significance level of p<0.001, all four methods were able to correctly determine if a given spine level was correct with an accuracy of around 94%. Detectors One, Two, and Three were within a 95% confidence interval of each other in being slightly over 94% accuracy but had a slight liberal bias. Detector Four had a very slightly lower accuracy of 93.8%, but a conservative bias.

Conclusions: All four Detection Methods demonstrated strong ability to correctly predict whether a spine level was the correct level. The slight liberal biases in Detectors One, Two, and Three makes them slightly inferior to Detector Four because a false positive is more dangerous in choosing the right level than is a false negative.

Patient Care: We identified an effective technique to improve surgical outcomes by reducing the incidence of wrong level spine surgery.

Learning Objectives: By the conclusion of this session, participants should be able to: 1) Describe the importance of selecting the right level when conducting spinal surgery and the consequences of failing to do so, 2) Discuss, in small groups the identification correct spine level in spinal surgeries and the standard approach to so doing, and 3) Identify an effective technique to improve surgical outcomes by reducing the incidence of wrong level spine surgery.

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