Effect of intraoperative navigation on operative time in 1-level lumbar fusion surgery.

The use of intraoperative image guided navigation (NAV) in spine surgery is increasing. NAV is purported to improve the accuracy of pedicle screw placement but has been criticized for potentially increasing surgical cost, a component of which may be prolongation of total operative time due to time required for setup and intra-operative imaging and registration. In this study, we examine the effect of the introduction of O-Arm conical CT spinal navigation on surgical duration. We retrospectively analyzed consecutive freehand (FH) (n=63) and NAV (n=70) 1-level lumbar transpedicular instrumentation cases at a single institution by a single surgeon. We recorded setup and procedure time for each case. NAV was associated with significantly shorter total operative time for 1-level lumbar fusions compared to FH (4:30+/-0:42 hours vs. 4:53+/-0:39hours, p=0.0013). This shortening of total operative time was realized despite a trend toward slightly longer setup times with NAV. We also found a significant decrease in operative length over time in NAV but not FH cases, indicative of a "learning curve" associated with NAV. The use of NAV in 1-level lumbar transpedicular instrumentation surgery is associated with significantly shorter total operative time compared to the FH technique, and its efficiency improves over time. These data should factor into cost-effectiveness analyses of the use of NAV for these cases.