Simulation Two Interbody Fusion Was Into L4-5Intervetrebral, Comparative Left And Right Reversed Bending Analysis Of Strain

Background：The role of social progress and development of moderntechnology, many factors, life expectancy is increasingly extended, graduallyincrease the proportion of the elderly population, with the advent of an agingpopulation, high incidence of elderly with degenerative lumbar spine. Lumbardegeneration caused by lumbar disc herniation, spinal stenosis, lumbarspondylolisthesis, such as lead to the waist, long-term pain, affecting the workand quality of life of patients. Previous spinal fixation devices on thebiomechanical evaluation in order to simulate more than lumbar spine fractureand dislocation of the spine, degenerative fixed to fixed equipment, research incompression, flexion, extension, left turn, right turn, reverse the state to imposeload or torque, displacement or torsion angle to the size of the stabilityevaluation.Now Given the need for clinical practice, the author Strain measurementtechniques and theory, Biomechanics of the theory and technology,Simulationtwo Interbody fusion was into L4-5intervertebral, comparative left and rightreversed bending strain analysis system, the objective analysis and evaluationof clinical lumbar degeneration choose reasonable integration provide ascientific basis.Objective: By simulating the L4-5intervertebral was grafted into allograftbone Wedge fusion and Cylindrical fusion cage，after comparing the size of thestrain around the bone and provide mechanical parameters for clinical.Methods: lumbar spine specimens were obtained from fresh and healthy12-month-old adult calves are male.Remove the L3-L5lumbar spine specimenswithin two hours after put to death in cattle; eight specimens immediately afterremoving the specimen processing to remove the specimen attached to the muscle to retain Anterior longitudinal ligament, interspinous ligament,ligamentum flavum, facet joint capsule. randomly selected4specimens for thegroup into allograft bone fusion; randomly selected4specimens for the groupinto pure titanium cage. Simulation of anterior discectomy L4-5disc herniation,Simulation of anterior lumbar spine surgery in the front lumbar windows,removal of part of the anterior longitudinal ligament, the fibrous ring, completeremoval of disc, the L4-5bone endplate reserved. First, the principles andtechniques of the strain electric analog L4-5disc prolapse Strain measurementson the wedge of allogeneic bone interbody fusion device group and allogeneicbone cylindrical interbody fusion group. SMD parts in specimens in therelevant parts of each group of specimens, metallographic sandpaper polishedsmooth, then alcohol and repeatedly washing the patch site, and then withacetone repeatedly cleaning the patch site, clean, strictly in accordance with thepaste of the resistance strain gauge technology to Beijing Chemical Plant502quick-drying glue paste specimens of each patch site resistance strain gauges.Resistance strain gages paste finished, paste the proximal terminal of thecorresponding change in piece, electronic strain gauge Lead solder on theterminals after the welding wire. Each specimen was imposed on40N CM,80N CM,120N CM moment, measured by the strain points of strain.According Hooke’s law calculation of each group of specimens left, the right toreverse the stress values of the measuring point in the bending state, thenSpSS13.0software to complete the statistical processing using completelyrandomized single-factor approach to data analysis, paired t-test compare thetwo sets of data,significant difference (p＜0.05).Results: Maximum strain and stress was the1st measurement point, thispoint is anterior upper edge of the L5vertebral body; The site was the edge ofbone of grafting; Analysis of the site was near the bone of grafting. The L4-5intervertebral space was slotted and was grafted allograft bone fusion, Causing the stress concentration area, In the Moment，the area is subjected to high stress.Minimum strain and stress was the sixth measurement point. The sixthmeasurement point was inferior articular process of L4vertebral body, Themeasurement points was far away from grafting bone area, Therefore, it wasthe minimum strain and stress.Conclusions：It was demonstrated that the1st measuring point: theanterior margin of L5vertebral body in flexion,and extension was dangerouspart, occuring maximum strain and maximum stress. Allograft interbody fusionstrain and stress of each point was less than Cylindrical fusion cage.