Innovative 3D Navigation Module for Precise Unilateral Pedicle Screw Combined with Contralateral Translaminar Facet Screw Placement in Lumbar Spine Surgery.

Objective: The incidence of degenerative diseases of the lumbar spine has increased in recent years. Unilateral pedicle screw combined with contralateral translaminar facet screw fixation offers the advantages of less trauma, better stability, and fewer complications. However, the surgical difficulty and suboptimal pinning accuracy of translaminar facet screw placement in clinical practice limit its use. Therefore, in this study, we designed a novel suspended 3D-printed navigation module to facilitate fast and accurate intraoperative screw placement. The aim of this study is to investigate the digital design, precise implementation, and evaluation methods for placing unilateral pedicle screws in the lumbar spine combined with translaminar facet screw placement using a new suspended 3D navigation module.

Methods: This retrospective study included 46 patients with single-level lumbar lesions who underwent spine surgery at the Affiliated Hospital of Putian University between June 2022 and December 2023. The suspended navigation module was designed digitally. Preoperative screw placement was simulated using 3D printed models, followed by an intraoperative accurate screw placement facilitated by the navigation module and a postoperative evaluation of the accuracy of screw placement. The absolute difference in three-dimensional coordinates of the inlet and outlet points of the preoperative design and the postoperative screw-nail channel served as the precision index.

Results: In a study involving 46 patients, surgery was successful with 92 pedicle screws and 46 translaminar facet screws placed without any penetration of the cortex. The difference in coordinates before and after screw insertion was minimal, with entry points varying between 1.21 to 1.36 mm and exit points between 1.97 to 2.46 mm. When screw accuracy met certain thresholds, there was no significant difference between preoperative design and postoperative coordinates, indicating precise replication of the surgical plan.

Conclusion: The new suspended 3D navigation module enables the precise placement of unilateral pedicle screws in the lumbar spine combined with translaminar pedicle screws for precise surgery.