Endoscopic Anatomy of the Lumbar Spine: Implications for Advancements in Biportal Endoscopic Spine Surgery
10.21182/jmisst.2025.02411
- Author:
Ajid RISDIANTO
1
;
Happy KURNIA
;
M. Farhan ISMAIL
;
Suhartono
;
Antonius Gunawan SANTOSO
;
Yuriz BAKTHIAR
;
M. Thohar ARIFIN
Author Information
1. Doctoral Study Program at Medical Science and Health Science, Universitas Diponegoro/Neurospine Surgery Division, Kariadi Hospital, Semarang, Indonesia
- Publication Type:Technical Notes
- From:
Journal of Minimally Invasive Spine Surgery and Technique
2026;11(Suppl 1):S94-S101
- CountryRepublic of Korea
- Language:English
-
Abstract:
Objective:Biportal endoscopic spine surgery (BESS) has emerged as a minimally invasive alternative for lumbar decompression, offering improved visualization with reduced tissue disruption. Therefore, this study aims to identify key anatomical considerations, particularly interlaminar-disc mismatch and the “banana-shaped” curvature of the lamina, and to examine their impact on portal trajectory, alignment of the surgical corridor, and preservation of spinal structures.
Methods:A retrospective, video-based analysis was conducted on 23 BESS lumbar decompression cases performed between January and March 2024. Surgical levels included L3–4 (n=3), L4–5 (n=17), and L5–S1 (n=3). Intraoperative anatomical landmarks were assessed independently by 2 spine surgeons. Interobserver agreement was evaluated using Cohen kappa, based on the identification of 3 landmarks per case in 23 cases, calculated with unweighted kappa. Visualization quality was scored on a 3-point scale. Cranial and caudal interlaminar-disc mismatches were measured and averaged.
Results:Interlaminar-disc mismatch was identified in 93% of cases, with cranial and caudal mismatches ranging from 5.5±1.02 mm to 8±1.2 mm. Laminar curvature was consistently observed at L4–5 and L5–S1, which required a medial-caudal portal. In addition, the superior articular process (SAP) served as a reliable fluoroscopic and endoscopic landmark, facilitating safe access to the intervertebral disc. A limited medial facetectomy provided adequate operating space. The findings also demonstrated high interobserver reliability for anatomical identification (κ=0.84), and the use of layer-specific flavectomy preserved the inner layer of the ligamentum flavum.
Conclusion:Successful BESS requires integrating detailed anatomical understanding with intraoperative adaptability. Recognizing interlaminar-disc mismatch, laminar curvature, and SAP orientation enables optimal portal placement and targeted decompression. These principles are essential for achieving reproducible and safe outcomes in BESS.
