A Biomechanical Analysis of Stress Transfer Behaviors Within the Necrotic Area of Femoral Head secondary to Changes in Core Placement Direction on Various Distributions of Necrotic Areas in the Osteonecrosis of the Femoral Head

대퇴골두 무혈성 괴사증에 있어서 괴사 영역의 위치와 천공방향의 변화에 따른 대퇴골두 괴사영역에서의 응력 변화 분석에 대한 생체역학적인 고찰

The purpose of this study was to test the hypothesis that even very small change of the cue direction in the treatment of the early osteonecrosis could affect the outcomes of operation. For this, the changes in stress transfer within the necrotic area of the femoral head were investigated under various directions and placements of the core utilizing finite element method. The loading of 3188N, which represents after-heel-strike, was imposed in cubic cosine pattern. All nodes on the most distal surface of the model were constrained in all directions. All materials included were assumed to have linear-elastic behavior. The result says that the critical stress, which causes collapse of the femoral head, was reduced when the core was oriented toward the posterior side of the femoral head regardless of location of the necrotic area. The same result was obtained either fibular bone grafting or cementation was adopted. As a consequence, the biomechanical study suggests that the core should be directed toward the loading point where the resultant force is applied to get more desirable treatment of the osteonecrosis of the femoral head in the early stage.