Degenerative lumbar spinal stenosis (LSS) is a common spinal disorder, with a prevalence of approximately 8% in the general population [1]. Decompression surgery remains the gold standard for treating LSS with predominant radiculopathy, stable biomechanics, and poor response to conservative therapy [2]. Traditional open decompression is relatively invasive and often results in persistent back pain, prolonged recovery, and potential segmental instability caused by excessive facet joint resection [3]. Over recent decades, substantial advancements in minimally invasive spine surgery have optimized therapeutic strategies for spinal disorders, offering novel and effective treatment alternatives [4]. Among these techniques, unilateral laminotomy for bilateral decompression (ULBD) achieves bilateral neural decompression through unilateral laminar resection while preserving posterior midline structures and maintaining favorable biomechanical stability [5,6]. However, conventional ULBD presents limitations such as restricted visualization and reduced access to the contralateral side [7]. Endoscopic techniques have addressed these issues by minimizing trauma and improving intraoperative visualization. The biportal endoscopic (BE) approach further minimizes instrument crowding and enhances surgical ergonomics by separating the viewing and working channels [8]. Consequently, ULBD performed via the BE approach (BE-ULBD) has become a widely adopted and effective treatment option for LSS [4].

Despite these advantages, establishing the working channel during BE-ULBD is typically performed manually and without direct visualization, making it a technically demanding due to the complex spinal anatomy. Inexperienced surgeons often encounter challenges in achieving accurate localization, necessitating repeated fluoroscopic guidance. This not only prolongs operative time but also increases radiation exposure for both the patient and the surgical team [9]. Furthermore, although BE-ULBD provides a magnified endoscopic view, it lacks the direct anatomical visualization offered by open surgery. Surgeons may become disoriented during the procedure, increasing the risk of unnecessary maneuvers, inadvertent tissue injury, and extended operative duration [10,11].

With the advancement of digital medical technologies, intraoperative navigation has emerged as a promising solution to these challenges [12]. By providing real-time visualization of anatomical structures and instrument trajectories, navigation systems have been shown to enhance surgical precision, reduce fluoroscopy usage, and improve overall procedural efficiency [13]. However, existing systems present distinct limitations: optical navigation can be compromised by light path occlusion [14], whereas electromagnetic navigation is susceptible to interference from metallic surgical instruments [15].

To address these shortcomings, a novel integrated optical-electromagnetic surgical navigation system has recently been developed [16]. By combining the advantages of both modalities, this system provides enhanced stability and accuracy. Nevertheless, its clinical application in BE-ULBD has not yet been reported in the literature. In the present study, we retrospectively analyzed clinical data from patients who underwent navigation-guided BE-ULBD (Ng-BE-ULBD) using the integrated system and compared them with those who received C-arm-guided BE-ULBD (C-BE-ULBD). The aim was to compare operative parameters and short-term clinical outcomes between the two techniques and to preliminarily assess the safety and feasibility of Ng-BE-ULBD.

This study compared operative parameters and early outcomes between C-BE-ULBD and Ng-BE-ULBD in patients with LSS. Among the 180 patients who underwent BE-ULBD, postoperative pain, claudication, and functional impairment improved significantly. The mean hospital stay was approximately half that reported for conventional open decompression in previous studies [17]. Importantly, without compromising surgical safety or short-term clinical efficacy, the Ng-BE-ULBD group demonstrated a shorter total operative time and a significantly lower number of fluoroscopic exposures compared with the C-BE-ULBD group.

Although BE-ULBD has been widely adopted, several technical challenges persist, particularly in establishing the working channel and identifying anatomical structures and instrument positioning intraoperatively, as noted in the introduction. Reducing radiation exposure, enhancing precision, and minimizing complications remain major goals. Navigation-assisted spinal endoscopic surgery offers a promising avenue to address these issues [18]. Currently, optical-electromagnetic navigation systems are the predominant technologies applied in spine surgery [14]. While these systems have improved surgical accuracy and efficiency, each possesses distinct limitations. Optical systems rely on infrared tracking and synchronization of computed tomography images with fixed reference arrays to provide real-time visualization of instruments and anatomy [18]. However, accurate function depends on maintaining a clear line of sight, as any obstruction of reflective markers within the camera’s field can compromise precision. Moreover, reflective markers affixed on instrument handles restrict use to rigid tools [19]. Electromagnetic navigation systems, comprising a control unit, field generator, and sensors, create localized electromagnetic fields to track instruments and patient anatomy without requiring direct visual contact [14]. Despite this advantage, these systems are prone to interference from ferromagnetic materials, and registration procedures can be time-consuming [18]. In this study, we employed an integrated optical-electromagnetic navigation system that merges both technologies into a single platform. Algorithmic optimization of spatial transformation and positioning accuracy allowed unified registration and real-time verification across optical, electromagnetic, and imaging coordinate systems, ensuring high navigation precision. The system enables seamless intraoperative switching, real-time drift monitoring, and flexible instrument tracking while minimizing electromagnetic interference. By integrating the strengths of both systems, this platform effectively addresses the limitations of traditional navigation technologies.

Retrospective comparison of surgical parameters and outcomes revealed multiple advantages of navigation-assisted BE-ULBD. The optical-electromagnetic navigation system provided rapid and accurate localization, preventing segmental errors and improving overall surgical efficiency [20]. Compared with C-BE-ULBD, the Ng-BE-ULBD approach significantly shortened the total operative time for LSS treatment. Detailed analysis indicated that navigation offered its greatest benefit during catheter placement. Without navigation, surgeons depend on surface landmarks and repeated C-arm fluoroscopy for localization. In contrast, navigation supplies real-time anteroposterior and lateral imaging with instrument tracking, reducing fluoroscopy frequency and the risk of collateral tissue injury. Although decompression time was shorter in the Ng-BE-ULBD group, the difference was not statistically significant. Nevertheless, navigation aids decompression by compensating for the two-dimensional limitations of the endoscopic view, which lacks complete anatomical context. Under optical-magnetic guidance, surgeons can visualize instrument position and the maximal safe working range in real time through orthogonal navigation displays, thereby enhancing precision and efficiency while minimizing radiation exposure to both surgeons and patients [21]. Consistently, the Ng-BE-ULBD group exhibited significantly fewer fluoroscopy shots than the C-BE-ULBD group.

However, optical-electromagnetic navigation did not improve short-term clinical outcomes following BE-ULBD. Both groups achieved comparable pain relief and functional recovery, consistent with prior navigation-assisted studies [22–24]. This observation likely reflects the proficiency of spine surgeons performing standardized BE-ULBD procedures. Operative efficacy was maintained through longer operating times and more frequent fluoroscopy, restricting navigation’s measurable impact primarily to improved efficiency. Additionally, the VAS and ODI scales used in this exploratory study, though validated, may lack the sensitivity to detect subtle improvements in decompression quality and are influenced by baseline variability and psychosocial factors, potentially masking navigation-specific benefits. Future research should incorporate more sensitive outcome measures for complex pathology or extend follow-up durations to better evaluate navigation’s clinical value. With respect to safety, complications were infrequent and well controlled in both groups. Dural tear was the most common complication, consistent with AO Foundation statistics [25]. Under endoscopic visualization, muscles, facet cysts, and ligaments are difficult to distinguish, increasing the risk of complications [26]. Inadequate decompression, observed more frequently in the C-BE-ULBD group, remains a major cause of postoperative dissatisfaction [27]. Navigation enhances intraoperative safety by clearly delineating instrument direction and depth and by displaying familiar anatomical structures that guide decompression. Moreover, real-time image guidance assists surgeons in managing anatomical variations, particularly in complex cases [28], and may accelerate skill acquisition and shorten the learning curve for novice surgeons [29,30].

In summary, optical-electromagnetic navigation-assisted BE-ULBD effectively reduces operative time and radiation exposure while improving procedural precision and safety. The system also demonstrates potential for optimizing complex case management and facilitating technical training for junior surgeons. Nevertheless, several limitations must be acknowledged. First, the single-center retrospective design introduces potential bias. Second, subgroup analyses controlling for decompressed levels yielded small sample sizes in some groups. Finally, as an exploratory investigation, the follow-up duration was relatively short and outcome measures lacked granularity. Large-scale, multicenter prospective studies with extended follow-up are warranted to further validate the clinical efficacy of this novel navigation system.

Optical-magnetic navigation-assisted BE-ULBD provides precise intraoperative guidance, enabling spine surgeons to achieve accurate decompression while reducing radiation exposure and operative time. This approach enhances surgical efficiency and safety, with distinct advantages in multilevel or complex cases, offering surgeons greater convenience and control.