去松质骨截骨治疗强直性脊柱炎后凸畸形的有限元分析

摘要

背景:强直性脊柱炎后凸畸形是一类脊柱矢状面失平衡的脊柱畸形,由于重心移位,脊柱的生物力学也较复杂,目前对其后凸畸形矫形后的生物力学研究鲜有报道.目的:应用计算机辅助软件建立强直性脊柱炎后凸截骨三维有限元模型,并分析其生物力学特性.方法:建立强直性脊柱炎后凸畸形三维有限元模型,根据20°,30°,40°截骨角度模拟去松质骨截骨矫形手术方案,并分析其矫形效果及生物力学.结果与结论:①成功建立了完整强直性脊柱炎后凸截骨矫形三维有限元模型,并且模拟手术操作建立了截骨角度分别为20°,30°,40°的去松质骨截骨模型;②3组不同截骨矫形方案中,去松质骨截骨30°矫形程度最佳,并且应力分布较小,其T12、L1、L2、L4、L5、S1、钉棒应力分别为7.3461,11.952,72.783,81.368, 28.144,41.114,109.69 MPa;③在去松质骨截骨术30°截骨方式下,术后矫正Cobb角为1.4°,既可获得较佳的矫形程度,同时也能降低由于内固定应力分布集中导致并发症的发生率.%BACKGROUND: Kyphosis in ankylosing spondylitis is a kind of spinal sagittal imbalance; due to center of gravity displaced and complicated biomechanical properties of the spine, the spinal biomechanics after kyphosis correction is little reported. OBJECTIVE: To establish a three-dimensional finite element model of the spine after osteotomy for kyphosis. METHODS: A three-dimensional finite element model of kyphosis in ankylosing spondylitis was established, simulating three kinds of osteotomy orthopedic programs (osteotomy angle in 20°, 30° and 40°), and the orthopedic effect and biomechanics were analyzed.RESULTS AND CONCLUSION: (1) The three-dimensional finite element model of finite element model of kyphosis in ankylosing spondylitis was established successfully, and simulated three kinds of osteotomy orthopedic programs at the angles of 20°, 30°, and 40°. (2) The best osteotomy angle was 30°, the stress distribution was less, and the stress on the T12, L1, L2, L4, L5, S1and rod was 7.346 1, 11.952, 72.783, 81.368, 28.144, 41.114, and 109.69 MPa, respectively. (3) Under 30°osteotomy angle, the postoperative Cobb angle is 1.4°, which not only obtains better orthopedic effect, but also reduces the incidence of complications caused by stress concentration.