Data Analysis Of Spinal Canal Safety Triangle And Effective Quadrangle In Lumbar Spine Magnetic Resonance

Background and PurposeThe imaging data of the safe working area of the intervertebral foramen approach after the removal of the bone structure were studied,The evaluation can provide the data basis for the design of endoscopic intervertebral fusion through the maximum diameter of the endoscope in this area,understand the relationship between nerves and osteoarticular processes,and clarify the running relationship of nerves in this area and the safe range of operation.MethodsA study of 100 patients with lumbar spine MRI was performed to rule out fractures,infections,tumors,lumbar instability and patients with congenital spinal developmental defects after open lumbar spine.In the coronal position,measure the distance from the intersection of bilateral nerves and the dura mater to the plane of the lamina of the lower edge of the lower vertebra(A),and measure the vertical distance from the upper edge of the lower vertebra to the exit nerve(B).The length of the exit nerve at the upper edge of the lower vertebral body(C),the maximum distance(D)of the intervertebral space is measured,the distance between the lower edge of the vertebral body and the exit nerve(E).The vertical distances from the exit nerve root to the pedicle were measured on the sagittal position and recorded as(h1,h2,h3).ResultsThe nerve safety triangle from L2-3 to L5-S1 is a right-angled triangle whose base gradually increases,and the height decreases from L2-3 to L4-5.The average height increases from 16.4mm to 20.2mm and then decreases to 18.6mm,The average base length increased from 12.1mm to 16.1mm.The angle between the nerve and the dura mater decreases from L2-3 to L3-4 and then increases.The smallest angle is at the level of L3-4(average 33°),and the largest angle is at the level of L5-S1(average43°).The intervertebral space height gradually increases from L2-3(average value,5.8mm)to the maximum disc height at the L3-4 level(average value,9.3mm),and then gradually decreases to the L5-S1 level(average value,6.8mm).The volume of the effective quadrilateral gradually increased from L2-3 to L4-5,and then decreased,with an average value from 65.7 mm2)gradually increasing to 98.9 mm2 and then decreasing to 79.3 mm2.On the longitudinal axis of the outer edge of the pedicle,the distance from the pedicle L2-3 is greater than 8.9mm,L3-4 is greater than 13.1mm,L4-5 is greater than 15.1mm,and L5-S1 is greater than 14.2mm as a safe puncture position,which is reached after puncture The entry of the posterior osseous structure can be considered as a safe operation space.ConclusionsThe maximum average diameter of an endoscopic intubation through a safety triangle in the spinal canal is significantly larger than the maximum average diameter of an endoscope channel for clinical use,allowing a larger diameter cannula to be used for operation.There is a limit to the effective work area in the Kambin triangle,which should be considered when developing tools and instruments.