Lenke 2型特发性脊柱侧凸三维矫形手术的有限元模拟

目的 利用建立的Lenke 2型青少年特发性脊柱侧凸(adolescent idiopathic scoliosis,AIS)三维有限元模型,分别仿真模拟前路、后路手术矫形操作,探讨其最佳手术方案。方法 建立Lenke 2型AIS的有限元模型,分别模拟前路和后路共5种不同的矫形方案,比较不同手术方案的矫形效果和双肩平衡参数的变化。结果 5种不同矫形方案有限元模拟术后的上胸弯冠状面Cobb角和矫形率分别为:21.5(44.8%)、26.5(32.1%)、28.1(27.9%)、34.1(12.5%)、32(17.9%),各矫形方案的主胸弯矫正率无明显差别。胸椎矢状面生理后凸得以维持。5种矫形方案术后各双肩平衡影像学参数较术前有所升高,除方案A(上端固定椎为T2)外,其余各方案的喙突高度差均＞9 mm,锁骨角均＞2.5°,锁骨倾斜角差均＞4.5°。结论 对于左肩高的含结构性上胸弯Lenke 2型AIS,上端固定椎选择T2且完全融合上胸弯,可取得上胸弯、主胸弯良好的三维矫形和双肩平衡。部分融合上胸弯(上端固定椎为T3、T4),上胸弯的矫正率稍差,术后容易出现轻度到中度双肩失平衡。前路或后路选择性胸主弯融合,难以恢复上胸弯的正常脊柱序列,术后会导致轻度到中度双肩失平衡。

Three-dimensional finite element simulation of surgical correction for Lenke 2 type adolescent idiopathic scoliosis

Objective To simulate different anterior and posterior correction strategies using finite element model of Lenke 2 type adolescent idiopathic scoliosis(AIS),in an effort to seek the optimal surgical protocol.Methods The finite element model of Lenke 2 type AIS was established and used to simulate five surgical strategies.The effectiveness and shoulder balance parameters were compared among different surgical approaches.Results The coronary proximal thoracic(PT) Cobb angle and corrective rates of the five surgical strategies were 21.5(44.8%),26.5(32.1%),28.1(27.9%),34.1(12.5%),and 32(17.9%).The corrective rates for the main thoracic curves were not significantly different among the five strategies,and the physiological sagittal configuration was maintained.Postoperative radiographic shoulder balance parameters were increased for all five surgical protocols.Except for strategy A(posterior fusion from T2 to T11),other four strategy achieved the following outcomes: coracoid height difference>9 mm,clavical angle>2.5° and clavicular tilt angle difference>4.5°.Conclusion Simulation of posterior correction and fusion to T2 including both thoracic curve can achieve excellent three-dimensional corrective results and balanced shoulders for Lenke 2 type AIS model with preoperative left elevated shoulder.Partial fusion of PT curves to T3 or T4 results in inferior corrective rate of PT curve and mild or moderate shoulder imbalance.Simulation of anterior or posterior selective main thoracic curve fusion has very low spontaneous PT corrective rate and can lead to deteriorated shoulder imbalance slight to moderate degrees.