Introduction of Special Issue: New Challenges and Technical Innovations in Endoscopic Spinal Surgery

1. Expansion of Surgical Indications for Complex Spinal Pathologies

Endoscopic spine surgery has evolved well beyond conventional lumbar discectomy and single-level decompression. Several studies demonstrate successful application of full-endoscopic and UBE techniques to anatomically complex and technically demanding spinal disorders.

Thoracic disc herniation, particularly when accompanied by calcification, remains one of the most technically demanding conditions in spine surgery. Two studies introduce biportal endoscopic techniques, including a novel transdural approach, to address these challenging lesions safely and effectively [1,2].

Another study presents a combined endoscopic transnasal anterior decompression with posterior fixation as a minimally invasive solution for pediatric atlantoaxial tuberculosis associated with quadriplegia, expanding the role of endoscopic surgery in complex infectious spinal diseases [3].

In addition, endoscopic techniques are extended beyond decompression toward spinal reconstruction through direct pars interarticularis repair using the "Smiley Face Rod" technique, illustrating the expanding reconstructive capabilities of endoscopic surgery [4].

Favorable outcomes are reported from a 1-year follow-up of a modified transfacet full-endoscopic lumbar interbody fusion, further supporting the feasibility and efficacy of advanced endoscopic fusion techniques [5].

2. Technical Innovation and Solutions to Procedural Limitations

Another prominent theme throughout this issue is the development of reproducible surgical techniques designed to overcome technical limitations associated with conventional endoscopic procedures.

One study introduces a posterior oblique lateral full-endoscopic approach utilizing transverse process docking to minimize early nerve root manipulation during treatment of foraminal and extraforaminal lesions, thereby enhancing both procedural safety and surgical accessibility [6].

Furthermore, the interdisciplinary application of sports medicine technology is demonstrated through adaptation of an all-inside meniscal repair device for endoscopic annulus fibrosus repair, illustrating how innovations from other surgical specialties may facilitate further advancement of spinal endoscopy [7].

3. Patient Safety, Complication Management, and Standardization

As endoscopic spine surgery becomes increasingly integrated into routine clinical practice, greater emphasis has been placed on complication prevention, safety evaluation, and procedural standardization.

One investigation identifies early postoperative magnetic resonance imaging findings and drainage volume as useful predictors of epidural hematoma following unilateral biportal endoscopy, while another reports the rare occurrence of ligamentous hematoma after oblique lumbar interbody fusion, thereby expanding current knowledge regarding perioperative complications [8,9].

Another study proposes the concept of "structural mismatch" as a novel pathophysiological mechanism underlying persistent neurological deficits following biportal endoscopic cervical decompression, offering new insights into postoperative neurological recovery [10].

To further establish benchmark safety standards, a systematic review of publications in JMISST evaluates procedural trends and safety reporting, emphasizing the need for standardized reporting systems to facilitate comparison of surgical outcomes across institutions [11].

4. Patient-Centered Care and Integration of Digital Health Technologies

The final thematic area focuses on the optimization of perioperative management through objective patient assessment and integration of emerging healthcare technologies.

One study demonstrates the use of wearable smart devices for postoperative monitoring, providing objective functional assessments that complement traditional patient-reported outcome measures [12].

Another comparative study evaluates awake or regional spinal anesthesia versus general anesthesia during endoscopic transforaminal lumbar interbody fusion (TLIF). The findings suggest that reduced anesthetic burden may facilitate faster recovery while maintaining surgical efficacy, supporting minimally invasive anesthesia strategies for endoscopic spine surgery [13].

In addition, investigation of atelocollagen as a regenerative biomaterial provides encouraging evidence regarding its clinical utility for tissue healing and biological augmentation during spinal surgery [14].

Lastly,despite the well-recognized clinical advantages of MISS over conventional open procedures, widespread adoption continues to be limited by technical complexity and the associated learning curve. One article emphasizes the importance of implementing structured MISS education during residency and fellowship training to facilitate broader dissemination of these techniques and better align clinical practice with growing patient demand [15].

5. Video Articles

Furthermore, the 3 accompanying video articles in this JMISST special issue (July 2026) provide valuable educational demonstrations of these advanced surgical techniques. One video illustrates navigation-guided unilateral biportal decompression for the successful treatment of Bertolotti syndrome associated with far-out syndrome, demonstrating effective decompression of the exiting nerve root under navigational guidance [16]. Another presents the "crown reaming" technique, which enables controlled anterior facetectomy under direct endoscopic visualization during uniportal endoscopic TLIF, addressing one of the major technical challenges in endoscopic fusion surgery [17].

Looking ahead, rather than choosing between Uniportal (Full) Endoscopy and Unilateral Biportal Endoscopy (UBE), future advancements will likely focus on hybrid techniques and tailored instrumentation that optimize the advantages of both systems—thereby minimizing muscle trauma while expanding indication boundaries. Moreover, beyond structural repair (such as annulus closure), the endoscopic delivery of targeted biologics—including hydrogels, mesenchymal stem cells (MSCs), and growth factors—is expected to enable simultaneous mechanical repair and biological regeneration of the intervertebral disc [7].

Also, All 7 video articles published in JMISST special issue-April 2026 cover the latest techniques and clinical applications in the fields of Minimally Invasive Spine Surgery (MISS) and Endoscopic Spine Surgery (ESS).

Recent advances in endoscopic spine surgery have significantly broadened its clinical indications, expanding beyond simple lumbar disc herniations to encompass complex spinal pathologies. Traditionally, conventional open surgery was required for these challenging cases; however, open procedures carry inherent limitations, including significant surgical invasiveness, extensive paraspinal muscle and bone disruption, severe postoperative pain, prolonged recovery, and high complication rates. Importantly, in patients with systemic diseases or spinal metastases, open surgery can delay essential adjuvant therapies such as radiotherapy. In contrast, endoscopic spine surgery—utilizing both uniportal and biportal (UBE) techniques—offers clear clinical advantages, including enhanced anatomical visualization, reduced intraoperative blood loss, minimal tissue trauma, and accelerated rehabilitation.

Despite these advantages, endoscopic techniques face substantial technical and anatomical barriers when applied to high-difficulty spine conditions. Epidural metastatic tumors causing spinal cord compression require safe debulking to facilitate prompt postoperative radiotherapy, yet achieving adequate separation surgery endoscopically remains technically demanding [18]. In Arnold-Chiari malformations, delicate anatomical considerations around the brainstem and upper cervical spine limit conventional endoscopic approaches to foramen magnum and C1 decompression [19]. In the thoracic spine, central disc herniation presents a heightened risk of irreversible cord injury due to the narrow canal and frequently accompanying calcification [20]. Furthermore, infectious spondylodiscitis often presents low diagnostic yields with standard percutaneous needle biopsies, particularly in elderly or comorbid patients who require local anesthesia interventions [21]. In the lower lumbar spine, severe foraminal stenosis remains challenging due to anatomical obstructions such as a high iliac crest or sacral ala blocking Kambin triangle [22]. In cervical spine, full endoscopic discectomy and foraminotomy represents a valuable alternative to anterior cervical approaches for soft, foraminal disc herniations [23]. Lastly, lesions at the thoracolumbar junction carry a high risk of spinal cord or conus medullaris injury during thoracic approaches [24].

To address these obstacles, novel surgical techniques and procedural refinements have been developed. Safe decompression without cord irritation in the thoracic and thoracolumbar regions is now feasible through UBE transforaminal and percutaneous endoscopic thoracic discectomy techniques. Lower lumbar anatomical barriers can be bypassed using paraspinal approaches with large-caliber endoscopic systems, effectively minimizing nerve root retraction and irritation. For infectious spondylodiscitis, percutaneous endoscopic debride­ment and drainage performed under local anesthesia significantly improves pathogen detection rates while allowing minimally invasive drainage. Furthermore, endoscopic separation surgery for metastatic epidural tumors successfully facilitates early postoperative radiotherapy, and refined micro-endoscopic techniques now allow safe foramen magnum decompression.

The special issue of our journal features ten video articles demonstrating the clinical utility, safety, and procedural details of uniportal and biportal endoscopic spine surgery in treating these challenging spinal conditions. By illustrating step-by-step technical nuances and clinical outcomes, this collection aims to provide spine surgeons with actionable insights into the expanding capabilities and modern applications of advanced endoscopic techniques.

Conclusion

Collectively, the studies presented in this issue demonstrate the remarkable progress of endoscopic spine surgery across multiple domains, including expansion of surgical indications, refinement of operative techniques, enhancement of patient safety, incorporation of digital health technologies, and development of regenerative treatment strategies. Importantly, the collection integrates technical innovation with rigorous clinical evaluation and standardized outcome assessment, reflecting the ongoing maturation of endoscopic spine surgery as a comprehensive surgical discipline. Taken together, these contributions provide compelling evidence that endoscopic spine surgery has evolved beyond a minimally invasive alternative and is increasingly establishing itself as a principal modality in modern spine care.