Devoted to diagnostic and interventional spine imaging and therapeutics


Intraoperative Ct In Assesment Of Spinal Fusion Complications 2014

Category General Spine Gary X. Gong, MD, PhD Marty Auster, MD Purpose Intraoperative computed tomography has gained increasing recognition among modern neurosurgical techniques with significant impact on the outcome of the surgeries. Medial or lateral pedicle screw penetration with the potential to affect neural and vascular structures are well known and frequent problem associated with spinal fusion. This exhibit describes certain key anatomic or physiologic issues and imaging findings of the commonly encountered complications. Materials & Methods All the scans were performed on a 40-slice-CT scanner (Somatom Sensation Open Sliding Gantry, Siemens Healthcare, Forchheim, Germany) with a sliding gantry and a diameter of 82 cm mounted on rails within the floor of the OR was installed in a pre-existing operating room. The spinal instrumentations include the cervical, thoracic, and lumbar spine. Exams were performed with standard detector thickness and reconstruction sections without IV contrast with defined anatomic coverage. 2D Multiplanar reformats (MPR), Maximum Intensity Projections (MIP) and Volume rendering (VR) for improved visualization. Results Spinal screw fixations were performed to restore the mechanical function of the disrupted spinal column, either caused by trauma, tumor, deformity, infection, degenerative disease, or from instability caused by prior surgery itself. Nearly all the complications are potentially avoidable by performing the intraoperative CT scan before finalizing the hardware placement. The radiation exposure in MSCT-systems is acceptable as compared to conventional C-arm fluoroscopy. There is a steep learning curve for the staff including anaesthesiologists and scrub nurses as well as surgeons and radiologists. Conclusion After reviewing this exhibit, the viewers will gain an understanding of the myriad of potential complications that can be avoided by performing intraoperative CT before finalizing surgical hardware placement and this importance is emphasized through case illustration. However, some intraoperative CT findings may lead to unnecessary replacement of radiographically suboptimal screws that are otherwise not clinically significant. Unnecessary repositioning of screws could place the patient at an increased risk for complications related to screw placement and runs the risk of biomechanically weakening the construct. References 1. Assaker R, Reyns N, Vinchon M, Demondion X, Louis E: Transpedicular screw placement: image-guided versus lateralview fluoroscopy: in vitro simulation. Spine (Phila Pa 1976) 26:2160–2164, 2001 2. Bloch O, Holly LT, Park J, Obasi C, Kim K, Johnson JP: Effect of frameless stereotaxy on the accuracy of C1-2 transarticular screw placement. J Neurosurg 95 (1 Suppl):74–79, 2001 3. Gertzbein SD, Robbins SE: Accuracy of pedicular screw placement in vivo. Spine (Phila Pa 1976) 15:11–14, 1990 4. Glossop ND, Hu RW, Randle JA: Computer-aided pedicle screw placement using frameless stereotaxis. Spine 21:2026–2034, 1996 5. Hott JS, Papadopoulos SM, Theodore N, Dickman CA, Sonntag VK: Intraoperative Iso-C C-arm navigation in cervical spinal surgery: review of the first 52 cases. Spine 29:2856–2860, 2004 6. Roth J, Biyani N, Beni-Adani L, Constantini S. Real-time neuronavigation with high-quality 3D ultrasound SonoWand in pediatric neurosurgery. Pediatr Neurosurg 43:185–191, 2007