that include dislodged patient reference array, damaged or poorly viewed navigation tools, skiving or tool deection, and untracked anatomy shifts [36]. Additionally, some studies report select screws are placed without RAN due to surgeon discre­tion. This may include when a surgeon chooses to place freehand pedicle screws at the proximal end of a long fusion construct instead of re-registering for robot­assisted screws. Surgeon discretion may also include unreachable anatomy or the surgeon wanting to improve an already clinically acceptable screw. A list of reported issues in RAN platforms that have caused robot abandonment for the case or spe­cic levels is presented in Table12.5. Generally, when such issues occur, surgeons will revert to other techniques for screw insertion or skip the screw level if possible. In other cases, they may abandon the robot for the entire surgery. The amount of robot abandonment reported represents the overall utility of the technology to the surgeon. Understanding intraoperative abandonment is important as it results in sig­nicant nancial expenditure without associated benets and decreases operative room efciency. In smaller studies, robot abandonment has been reported as low as 0% [17, 33] and as high as 9.7% [37]. It should be noted that a large rate of abandon­ment can be reported in the smaller series of 20–30 patients if only a single case is abandoned. Larger cohorts seem to follow a similar trend. In one of the largest cohorts, Lee etal. reported a 0% abandonment rate in a series of 186 cases [35]. In another series including more than 100 cases, Jain etal. reported abandonment in 5 out of 106 cases (4.7%) where use of the robot was abandoned prior to any screw insertion. In the remaining 101 cases, only 5 pedicle screws (0.8%) required conver­sion to another method [18].