Anatomical measurement of the posterior structure of lumbar spine and design of the lumber laminar screw dynamic system / 中国基层医药

ABSTRACT

Objective To determine the lumbar anatomical structure parameters of the lumbar spine posterior column and its sample data of three-dimensional conformation,and based on these data to design the lumber laminar screw dynamic fixation system.Methods 20 human L3 ～ S1 bone specimens,the thickness of the lumber laminar region were measured to obtain the normal anatomical parameters of the lumbar laminar.And 20 healthy lumbar vertebrae L3-S1 for three-dimensional reconstruction were detected by CT scan,which could obtain the structure data of the normal lumbar posterior three-dimensional conformation,and to obtain conformational sample data of three-dimensional space of the posterior structure.Results Lumbar lamina medial 1/3 could serve as a spine laminar screw setting area by anatomical observations and measurements.Lamina thickness of L3-4 on average (6.6 ±0.9) mm,L5 ～ S1average (6.0 ± 0.6) mm.Lumber laminar screw length 6.5 ～ 8.0mm could meet the requirements of bilateral cortical fixation.Conclusion Lower lumbar spinal lamina area can serve as the region to fix the bilateral cortical bone screw,and the optimal length of the laminar screw is 6.5 ～ 8.0rmm.