[A finite element analysis of petal-shaped poly-axial locking plate fixation in treatment of Y-shaped patellar fracture].

To establish the finite element model of Y-shaped patellar fracture fixed with titanium-alloy petal-shaped poly-axial locking plate and to implement the finite element mechanical analysis.The three-dimensional model was created by software Mimics 19.0, Rhino 5.0, and 3-Matic 11.0. The finite element analysis was implemented by ANSYS Workbench 16.0 to calculate the Von-Mises stress and displacement. Before calculated, the upper and lower poles of the patella were constrained. The 2.0, 3.5, and 4.4 MPa compressive stresses were applied to the 1/3 patellofemoral joint surface of the lower, middle, and upper part of the patella respectively, and to simulated the force upon patella when knee flexion of 20, 45, and 90°.The number of nodes and elements of the finite element model obtained was 456 839 and 245 449, respectively. The max value of Von-Mises stress of all the three conditions simulated was 151.48 MPa under condition simulating the knee flexion of 90°, which was lower than the yield strength value of the titanium-alloy and patella. The max total displacement value was 0.092 8 mm under condition simulating knee flexion of 45°, which was acceptable according to clinical criterion. The stress concentrated around the non-vertical fracture line and near the area where the screws were sparse.The titanium-alloy petal-shaped poly-axial locking plate have enough biomechanical stiffness to fix the Y-shaped patellar fracture, but the result need to be proved in future.建立钛合金花瓣状多轴锁定板固定治疗髌骨 Y 形骨折的三维有限元模型，并进行力学分析。.使用 Mimics 19.0、Rhino 5.0、3-Matic 11.0 和 ANSYS Workbench 16.0 软件建立花瓣状多轴锁定板固定治疗髌骨 Y 形骨折的三维有限元模型。采用上下极约束，对髌骨下、中、上 1/3 关节面分别施加 2.0、3.5、4.4 MPa 压应力的方法，模拟屈膝 20、45 及 90° 时髌骨受到的应力，计算等效应力及位移值。.模型节点个数和网格个数分别为 456 839 和 245 449。模型最大等效应力为 151.48 MPa，出现在屈膝 90° 状态，小于钛合金和髌骨的屈服强度；骨折块的最大位移值为 0.092 8 mm，出现在屈膝 45° 状态，符合临床要求。最大等效应力和最大移位值分布在水平骨折线周围及螺钉较稀疏的部位。.钛合金花瓣状多轴锁定板固定髌骨 Y 形骨折力学性能良好，固定可靠，但实际效果有待进一步验证。.