Development And Finite Element Analysis Of Lumbar Spine Following Replacement Of Disc Prosthesis

Results show that in recent years, bone graft fusion technology is widely applied insymptoms in the treatment of lumbar disease. However, related studies have shown that thereare some disadvantages of fusion prosthesis, such as the decrease of lumbar spinal motion andadjacent segmental degenerative diseases. The clinical observation showed that spinal fusiontechnology-artificial disc replacement technology, obtained satisfactory clinical effect.However, if artificial disc replacement technology can avoid the disadvantages brought by thebone graft fusion technology, theoretical research is little.Objective and methods We take the patient as the prototype, who accepted the FrameArtificial lumbar disc7years ago, to study the effect of the adjacent segment vertebral bodyand disc by the Frame Artificial lumbar disc replacement prosthesis. We can evaluate this typeof Frame artificial lumbar disc by the study. Through the reverse technology,three-dimensional model reconstruction of L1~L4lumbar segment and Frame type artificiallumbar disc are made. Then two models are made, namely, the model of Frame type artificiallumbar disc system and Normal lumbar spine model by Pro/E software. With the aid of finiteelement analysis software ANSYS, we calculate the range of motion of the motionsegments(L2~L3), the stress of L1L2, L3L4lumbar disc and L2, L3vertebral body toevaluate artificial disc replacement prosthesis, namely, the effect of this Frame artificiallumbar disc in lumbar adjacent segments.Results and discussion The finite element results indicate that:1) The Frame artificiallumbar disc can maintain lumbar motion segments around65%of the activity, and thepositive pressure condition remain close to65%of the activity; the activity of bending motionis65%; extension, lateral bending condition keep65.7%,73.6%of the activity respectively;2)The Frame artificial lumbar disc has little changes in adjacent vertebral body. Although thestress of adjacent lumbar disc and vertebral body has increased, most of the increase is onlyaround10%.3) This Frame artificial lumbar disc has better fatigue resistance. Through thefollow-up study by the Fourth central hospital, the patient implanted the Frame artificiallumbar disc can live a normal life without any discomfort.Summarily, the artificial lumbar disc prosthesis well restores the biomechanical behaviorof the intact lumbar spine and produces little effect on the adjacent segments.