Navigated percutaneous lumbosacral interbody fusion: a feasibility study.

Introduction: Advances in surgical navigation have opened new possibilities for lumbosacral interbody fusion procedures. We have designed a novel navigated surgical method, Navigated Percutaneous Lumbosacral Interbody Fusion (NPLSIF), that enables lumbosacral discectomy and bone grafting to be performed percutaneously and safely.

Methods: To prove that NPLSIF is feasible from an anatomical perspective, it was simulated on 3D models of the lumbosacral spine created using CT data from 60 patients. Feasibility would be verified if both the working corridor and the S1 pedicle screw could be accommodated in the sacral ala without overlapping and without penetrating either the spinal canal or the anterior or upper sacral wall. In addition, the discectomy that could be achieved using NPLSIF was evaluated, and a surgical experiment was performed using a plastic torso model.

Results: The 3D modeling and surgical simulation were successfully completed in all cases. The feasibility of the NPLSIF approach was verified in every case, i.e., both the working corridor and the S1 pedicle screw were accommodated in the sacral ala without overlapping and without penetrating either the spinal canal or the anterior or upper sacral wall. The mean ratio of the area of discectomy that could be achieved by NPLSIF to the total area of the lumbosacral disc was 0.721 ±  0.065 (range: 0.57-0.894), 0.956  ±  0.045 (range: 0.8-1.0) and 0.945  ±  0.058 (range: 0.813-1.0) in the axial, coronal and sagittal planes, respectively. NPLSIF was also successfully executed on the plastic torso model. Preoperative planning on the navigation workstation took 5 minutes and each intraoperative CT scan took 30 seconds. Locating the entry point of the working corridor according to the preoperative plan took 3 minutes. Postoperative CT images and direct viewing of the plastic model revealed no penetration of the spinal canal or sacral wall.

Conclusion: The feasibility of Navigated Percutaneous Lumbosacral Interbody Fusion (NPLSIF) was verified from an anatomical perspective. We also demonstrated that an adequate discectomy can be achieved using the procedure. Cadaveric experiments and clinical trials are needed to further evaluate the efficacy and efficiency of NPLSIF.