An applied anatomical study of the lamina for posterior cervical UBE surgery based on three-dimensional CT reconstruction.

Abstract

To provide quantitative anatomical guidance for posterior cervical unilateral biportal endoscopic (PC-UBE) surgery by analyzing key parameters of the subaxial cervical lamina. This retrospective study analyzed preoperative cervical CT images of 200 patients (93 males, 107 females) scheduled for PC-UBE surgery. Based on three-dimensional reconstructed images, lamina-related parameters of the subaxial cervical spine were measured, including two angular parameters: laminar abduction angle (LAA) and laminar slope angle (LSA); four linear parameters: laminar height (LH), distance between inferior lamina margin and ligamentum flavum attachment (DLL), distance between the inferior lamina margin and inferior vertebral body margin (DLV), and transverse width of the facet joint (TWFJ). Parameters were compared across sex, side, vertebral level, and age groups. All measurements showed high reliability and bilateral symmetry. Age had a negligible effect. Males exhibited significantly larger linear parameters than females by 1-2 mm (p < 0.001), except for DLV, which was slightly greater in females at C4-C6 (difference < 1 mm, p < 0.001). No sex difference was found in angular parameters. Segmental analysis showed that from C3 to C7, consistent segmental trends were observed in both sexes. Using male data as an example: LAA decreased (C3: 53.19 ± 3.03°, C7: 43.27 ± 2.55°); LSA, LH, and DLL increased significantly from C3 to C7 (LSA: 93.23 ± 4.17° to 108.46 ± 3.81°; LH: 13.88 ± 1.17 mm to 18.61 ± 1.7 mm; DLL: 6.78 ± 1.25 mm to 11.96 ± 1.54 mm). DLV decreased to a minimum at C6, while TWFJ peaked at C6 (C3: 10.51 ± 1.27 mm; C6: 12.73 ± 1.11 mm). This study quantified the lamina anatomy of the subaxial cervical spine using CT reconstruction. Most linear parameters showed significant gender differences, and all varied predictably across C3-C7. The results provide key anatomical guidance for PC-UBE surgery, assisting in surgical planning and technique selection for procedures such as PCF, PCIF, and ULBD to enhance operative precision and safety.