Measurement of interspinous distance of Thai population in MRI and new design interspinous dynamic stabilization system of the lumbar spine

Abstract

Dynamic stabilization device aim to use in neurogenic intermittent claudication and early degenerative lumbar spinal stenosis not response to conservative treatment.Measurement of lumbar interspinous distance in this study aim to be a pilot study to know the estimation of interspious distance that refers to size of interspinous device. Objectives of this research are measure interspinous distance in Thai patients from sagittal view of MRI lumbar spine and to design and test new design dynamic stabilization system in Finite element method. Mean distance in female are L1-2 12.51 mm, L2-3 11.78 mm, L3-4 10.95 mm and L4-5 10.57 mm. Mean distance in male are L1-2 12.20 mm, L2-3 11.63 mm, L3-4 10.74 mm and L4-5 10.15 mm. Total mean distance from all sample are L1-2 12.36 mm, L2-3 11.71 mm, L3-4 10.84 mm and L4-5 10.36 mm. The differences in interspinous distance between males and females were not significant. The maximum and minimum distances from all samples are 14.2 mm and 8 mm respectively. New design device is U shape with cable to sling around adjacent spinous process. The device design to use by posterior approach, simple and less modularity, easy to manufacturer, can insert without any cut or destroy bony structure and can correct stiffness loss in early degenerative lumbar spine to near normal. Interspinous distance measurement can refer to range of size to manufacturer for the device to cover the use in Thai patients. New design device fulfill all goal describe above under finite element testing. The results of the project could provide design and data for the manufacturer and next step experiment for dynamic stabilization device suitable for Thai population.