clinical article J neurosurg Spine 25:339–344, 2016 T he lateral lumbar interbody fusion (LLIF) technique was initially described by Ozgur et al. in 2006. 11 LLIF has alternatively been described as extreme lateral interbody fusion or direct lateral interbody fu- sion. 6,11 This minimally invasive retroperitoneal transpsoas approach allows for a more robust discectomy than tradi- tional posterior approaches, while causing minimal blood loss and decreased postoperative pain. 5 However, the op- erative approach does place the surgeon directly adjacent to the lumbosacral plexus. To avoid nerve injury, neuro- monitoring and fuoroscopy are routinely used, which can result in signifcant radiation exposure to the surgeon. 1,14 Image-guided spinal navigation has been well-described for pedicle screw placement and has been shown both to increase accuracy and decrease radiation exposure. 9,10,15 We have previously shown the feasibility of using intra- operative cone-beam CT (iCBCT) with an image-guided navigation system (IGNS) for cage placement in LLIF. 12 The objective of this study was to evaluate the accuracy of cage placement and complications in a consecutive series of patients in whom this technique was used. Methods Retrospective analysis of a prospectively acquired da- tabase was performed to identify patients who underwent LLIF using the O-arm Surgical Imaging System (Medtron- ic, Inc.) for 3D image acquisition in conjunction with the aBBreViatiOnS ASIS = anterior superior iliac spine; iCBCT = intraoperative cone-beam CT; IGNS = image-guided navigation system; LFCN = lateral femoral cutaneous nerve; LLIF = lateral lumbar interbody fusion; PSIS = posterior superior iliac spine. SUBMitteD October 30, 2015. accePteD February 17, 2016. inclUDe when citing Published online April 22, 2016; DOI: 10.3171/2016.2.SPINE151295. Use of 3D CT-based navigation in minimally invasive lateral lumbar interbody fusion Jacob r. Joseph, MD, 1 Brandon w. Smith, MD, MS, 1 rakesh D. Patel, MD, 2 and Paul Park, MD 1 Departments of 1 Neurosurgery and 2 Orthopedic Surgery, University of Michigan, Ann Arbor, Michigan OBJectiVe Lateral lumbar interbody fusion (LLIF) is an increasingly popular technique used to treat degenerative lum- bar disease. The technique of using an intraoperative cone-beam CT (iCBCT) and an image-guided navigation system (IGNS) for LLIF cage placement has been previously described. However, other than a small feasibility study, there has been no clinical study evaluating its accuracy or safety. Therefore, the purpose of this study was to evaluate the accu- racy and safety of image-guided spinal navigation in LLIF. MethODS An analysis of a prospectively acquired database was performed. Thirty-one consecutive patients were identifed. Accuracy was initially determined by comparison of the planned trajectory of the IGNS with post–cage place- ment intraoperative fuoroscopy. Accuracy was subsequently confrmed by postprocedural CT and/or radiography. Cage placement was graded based on a previously described system separating the disc space into quarters. reSUltS The mean patient age was 63.9 years. A total of 66 spinal levels were treated, with a mean of 2.1 levels (range 1–4) treated per patient. Cage placement was noted to be accurate using IGNS in each case, as confrmed with intraoperative fuoroscopy and postoperative imaging. Sixty-four (97%) cages were placed within Quarters 1 to 2 or 2 to 3, indicating placement of the cage in the anterior or middle portions of the disc space. There were no instances of misguidance by IGNS. There was 1 signifcant approach-related complication (psoas muscle abscess) that required in- tervention, and 8 patients with transient, mild thigh paresthesias or weakness. cOnclUSiOnS LLIF can be safely and accurately performed utilizing iCBCT and IGNS. Accuracy is acceptable for multilevel procedures. http://thejns.org/doi/abs/10.3171/2016.2.SPINE151295 KeY wOrDS image-guided spinal navigation; lateral lumbar interbody fusion; DLIF; XLIF; minimally invasive spine surgery; O-arm Surgical Imaging System ©AANS, 2016 J neurosurg Spine Volume 25 • September 2016 339 Unauthenticated | Downloaded 07/15/22 12:06 AM UTC