Analysis And Clinical Application Of Normal Healthy People Lumbar Three-dimensional Structure Of The Data

BackgroundPedicle screws fixation system has become the common method of spinal internal fixation because of its good biological mechanical properties, and plays an important role in the development and progress of spinal surgery.The key technology of pedicle internal fixation is the vertebral pedicle screw must drill through the narrow osseous pipeline, which is in accordance with the long axis. Therefore, the most important parts in the technology are the drill point on the back lamina, direction and depth of the screw. Before that, the quantitative measurement of anatomical structure parameters in each vertebral segment plays the vital role for realizing and understanding of the overall population morphological characteristics of the spine and further research.Objectives1. To establish the3D model and method of measurement, which is supposed to be a scientific and reliable quantitative measurement of lumbar vertebral pedicle isthmus and related parameters of the anatomic structures, and discuss the reliability of the method.2. Collection of the normal and healthy people’s lumbar CT image data, using the above methods for actual measurement and data analysis, sums up and probes into the variation characteristics of lumbar form in Chinese population.3. Using of3D measurement and CAD-RE-RP technology, design and produce the personalized pedicle screws drill guide template (PDGT), and discuss the clinical application value and significance of PDGT in lumbar pedicle screws fixation surgery.Materials and MethodsMaterials1.5lumbar dry bone specimens of normal adult, which are treated after10%formalin.2. The research object aged25to50years old. Gender, height and weight are not in concern. Exclude the people with spine disease which changes the vertebrae structure and the patients the history of the spinal surgery. We collected76cases of lumbar CT scan imaging data in total.3. SIEMENS/Sensation64layer CT machine, scanning parameters:layer thickness2mm, layer distance2mm, the tube voltage is120kV, current225mAs, resolution512*512PXL.4. The German WENZEL-LH65three coordinate measuring machine, precision can reach0.1u m.5. Objet EDEN2503D reconstruction printer, precision is0.1-0.2mm6. FullCure720:Objet company medical transparent molding materialsMethods1. The physical contact measurement methods:the study used three coordinate measuring machines to take contact precise measurement on dry bone specimens, the precision can reach micron level, higher than what we need in the measurement accuracy.2.3-dimensional reconstruction measures:through a series of three dimensional analysis and the method of make out structural space auxiliary dot, line, plane, measures13parameters of lumbar anatomical structure data in normal healthy Chinese people, the precision can reach the same level of micron.3. CAD-RE-RP technology:use CAD software design the guidance holes on both side and the connection part between them, and then after the space integration, PDGT three dimensional model is formed. Then, make out the model by using RP technology and3D printers.Results1. We compared the3D model measurement and anatomical specimens measurement, there are no significant difference in all the measurement data between two measurement methods.2. The performance of lumbar anatomical structure parameters in the gender differences:in addition to SCSD of L1-L3men are less than women, the rest have significant difference between men and women of measuring the parameters were men greater than women.3. The performance of lumbar anatomical structure parameters in the age differences:we found that the data of DMBP in L1-L4, RPL in L2, RTSA in L4, LSSA in L2and L5, RSSA in L2, there was significant difference in three age groups. The mean carries on the comparison, found the relation among the three generally meet in mid-age group>young group> elder group.4. The performance of lumbar anatomical structure parameters in the weight differences: overall, the differences between the lumbar anatomical structure parameters and the weight is not big, a few statistically significant measures only limits on individual vertebral segment, lack of representative.5. The comparative research on both sides of the pedicle anatomical structure parameters: PW in L4and L5have significant difference between both sides, mean comparison find the left side>the right side. Considering the measured value of PL in L2, there has significant difference between left and right side, mean comparison find the left side<the right side. There have significant difference between both sides of L4and L5, in the measured value of TSA, mean comparison find the left side<the right side in L4, on the contrary, the left side>the right side in L5.6. Trend analysis research found that lumbar from high to low, DMBP,PW,TSA present a significant increasing trend, that is, the lower lumbar have the greater pedicle width and the greater outreach Angle; On the other hand, SCSD and SSA present a significant decreasing trend with the vertebral get lower.7. Design and make a personalized pedicle screws drill guide template (PDGT) device, with the entity specimens are paired, we found that it can fit the lamina and spinous process very well by closely connected to the surface and complete the purpose of the guide the screws drilling.Conclusions1. This study proposed3D measurement method based on CT image reconstruction of dry bone specimens, which has high accuracy, can really reflect the entity anatomy form, have important meanings in spinal anatomic studies.2. The influence factors study found that, the influence of age and weight to lumbar anatomical configuration structure is not big, but there are differences between men and women, men’s lumbar is slightly larger than women’s, but both of them have the same morphological structure proportion and the similar internal structure.3. Comparative study on the left and right side shows that higher lumbar morphological structures are symmetry, and lower ones have a certain degree of asymmetry.4. Trend analysis research found that the lumbar’s characteristics of the anatomical structure is related to the development and the stress condition of the whole spine, as well as the function of spinal cord and human physiological curvature of the spine.5. In addition, there is concern that the morphological structure in L5has markedly difference with other lumbar segmental, this has the important meaning to related spinal surgical procedures and evaluation.6. According to the analyzing and summarizing of spine shape and structure, we supposed that personalized treatment have important value in spinal disease areas.7. Personalized pedicle screws drill guide template (PDGT) is representative of the spine personalized treatment, with simple, scientific, practicability and other characteristics, plays an important role in auxiliary spinal surgery. Although there are still some shortages, the field is still has the very high clinical value and development prospect.