Three-dimensional finite element analysis on computer aided reconstruction of hip capsular ligament and its biomechanical significance

Objective To discuss biomechanical mechanism of reconstructed joint capsule ligament stabilizing hip joint by means of three-dimensional finite element analysis.Methods A finite element model of total hip arthroplasty(THA)including ischiofemoral ligament reconstruction was construtted by using finite element analysis software Unigraphics NX 2.0 and SolidWorks 2006 to simulate seated leg crossing and obtain peak resisting moment and range of motion prior to impingement.Results The current form of finite element model was characterized by large deformation multi-body contact,large interfacial sliding and high elasticity and could clearly reflect real anatomy and biomechanical behavior of ischiofemoral ligaments.Compared with model with only metal,model of ischiofemoral ligament reconstruction could reduce the peak polyethylene stress at the impingement site and at the head egress site by typically 17%and 31%respectively,increase peak resisting moment by nearly 57%and provide 2.29-fold stability.Conclusions As a discrete structure within the posterior capsule of the hip joint,the ischiofemoral ligament may be the most important contributor to the mechanical integrity of the posterior stability structure.The joint capsule ligament must be reconstructed in hip arthroplasty. Key words: Hip joint; Biomechanics; Finite element analysis; Computer aided design