椎弓根导向仪的研制及其临床应用

Design and clinical application of the pedicular exploratory apparatus

目的：为安全探查椎弓根，研制椎弓根导向仪（ＰＥＡ），以利正确置放椎弓根螺钉。方法：依据低频电流作用下生物组织电阻抗存在显著差异的原理，研制了ＰＥＡ；对６具新鲜猪脊柱椎弓根作电阻抗测定；采用ＰＥＡ将椎弓根螺钉钉尖固定至椎体前缘皮质下，治疗２４例胸腰段脊柱不稳定骨折。结果：①猪软组织的阻抗值为８０５～８５４Ω，椎弓根松质骨７５９～２２８９Ω，椎弓根皮质骨１９８３～２７８９Ω。②２４例胸腰段脊柱骨折患者中有２１例接近解剖复位。结论：测量电阻抗探查椎弓根，有助于正确定向及深置椎弓根螺钉。

Objective:To enhance the safty of pedicular exploration,a pedicular exploratory apparatus(PEA) was designed for correct placement of pedicle screws.Method:The PEA was designed according to the principle that there are significant difference of electrical impedance on biologic tissue at low frequency.The electrical impedance of pedicles of the lumbar spines of six swines were measured. 24 cases of thoracolumbar spinal fractures were treated using the pedicular screws taps to fix the subcortical bone of anterior bordor of vertebral body.Result:The resistances of the soft tissues were measured varying from 805 to 854Ω,the cancellous bone of pedicle 789￣2 289Ω,and the cortical bone of pedicle 1 983￣ 2 789Ω. Postoperatively,21 of 24 the cases of thoracolumbar spinal fractures were nearly achieved anatomic recovery.Conclusion:Accordingly,electrical impedance measurment during pedicle exploration prodivides a correct screw positioning and a deeper screw depth.The PEA is recommended for posterior approach operation of the thoracolumbar spinal fractures. Authors address\ Jiangyin Hospital of Traditional Chinese Medicine,Jiangsu,214400