Anatomic Surface Measurement of the Lumbar Laminae for Safely Resection During Percutaneous Endoscopic Surgery: A Computed Tomography-Based 3-Dimensional Morphometric Study

Objective: The aim of this study was to use computed tomography-based 3-dimensional morphometric imaging to precisely quantify the anatomic parameters of the lumbar laminae and increase the precision of laminar fenestration during percutaneous endoscopic spinal surgery.

Methods: Lumbar computed tomography data for the L1-L5 vertebrae of 62 patients (310 total vertebrae) were collected. Laminar width, height, thickness, and bilateral angle were measured in detail, and each parameter was compared and analysed.

Results: Measurements at the upper, middle, and lower planes of the laminae yielded mean surface laminar widths of 19.90 mm, 15.64 mm, and 18.07 mm, respectively. The safe lamina resection distances were 11.21 mm, 9.35 mm, and 9.63 mm at the upper, middle, and lower planes of the laminae, respectively. The mean surface laminar height was 21.83 mm at the articular process and 22.52 mm at the base of the spinous process. The mean values for laminar thickness were 6.33 mm, 5.96 mm, and 5.98 mm at the outer, central, and inner aspects, respectively. Overall, the angle between the laminae was larger in the upper lumbar vertebrae than in the lower lumbar vertebrae, with mean bilateral laminar angles of 124.08°, 125.45°, 125.00°, 116.19°, and 108.31° for L1 to L5, respectively.

Conclusions: This study has revealed significant anatomical diversity within the laminae of lumbar vertebral segments. These findings provide important anatomical information for surgeons performing precise laminar fenestration during endoscopic spinal surgery.