Combination Of Lumbar Vertebral Loading Apparatus And Gait Analysis With MTS In Biomechanics Study Of Screw Implantation In Fracture Of Lumbar Vertebra

Backgrounds and Objectives:With the development of modernization in China, frequent lumbar vertebral fracture has taken place, among which the fractures of thoracic and lumbar vertebral are more common. Improper treatment easily induces malformation, pain and unsteadiness of vertebral column. Rare studies on the biomechanics field of evaluation of therapeutic efficiency of thoraco-lumbar fracture could be seen recently. This study applied self-made lumbar loading apparatus associated with MTS and gait analysis system, to implant screw in ex vivo fracture lumbar vertebral, biomechanical testing and evaluation the treatment of screw implantation in injury lumbar vertebrae imitating of movement in vivo, to provide scientific evidence for clinical treatment of thoraco-lumbar vertebral fracture.Methods:Manufacture of 12 fresh frozen calf lumbar (L1～L5) vertebral bodies specimen system and applied L2 vertebral wedge osteotomy fracture model. Movement range of 3-D and 6 directions were compared between traditional method of 4-screw vertebral fixation and 6-screw in the injury model of anterior middle column in the lumbar vertebrae. Self-made lumbar loading apparatus was used associated with MTS and gait analysis system in data acquisition of lumbar movement range.Results:1.Three-dimensional spine tester and universal testing machine running smoothly, through which loading purpose on spinal specimens in three-dimensional movement can be achieved.2.After the proofreading, the gait analysis system of U.S. technology company can complete the experimental data collection, data processing in high accuracy.3. Movement ranges of flexion, extension, lateral bending in injury vertebral 6-screw fixation were less than that of control group and 4-screw fixation (P<0.01), rotation range of 6-screw fixation and 4-screw fixation was larger than that of control group (P<0.01), however the rotation range of 6-screw fixation was lesser than that of 4-screw fixation (P<0.01).4. ROM values of different movement directions after fatigue were larger than that of before fatigue in 4-screw fixation, significant differences could be seen between the two groups (P<0.05), however, similar condition occurred in 6-screw fixation, but no significant differences could be established (P>0.05)Conclusion:1.It is adaptive for 3-D movement examination of lumbar vertebral by utilization of self-made lumbar loading apparatus associated with MTS and gait analysis system in data acquisition of lumbar movement range.2.Stability of injured lumbar vertebral 6-screws fixation is higher than that of traditional 4-screws fixation, which is important in clinical treatment of lumbar vertebral fracture.3.Anti-fatigue characteristics of injured lumbar vertebral 6-screws fixation are better than that of traditional 4-screws fixation.