Analysis of impulsive stress wave propagating from distal femur to hip joint

Three-dimensional finite element model of femur and pelvis was prepared and the propagation of impulsive stress wave from the distal femur to the hip joint was analyzed by the dynamic finite element method. The finite element model with no articular cartilage was also used and the influence of cartilage on the impulsive stress was discussed. The stress concentration is mainly found around the femoral neck. The absolute value of minimum principal stress increases in the medial side, and the maximum principal stress increases in the lateral side during the propagation of stress wave. In this case, the absolute value of maximum principal stress is larger than that of minimum one. The stress of pelvis is small compared with that of femur, indicating that the impulsive stress is absorbed by traveling through the cartilage. The stress in the femoral neck and the pelvis becomes large in the case of no cartilage model, therefore it can be said that the hip joint with no cartilage has a higher risk of bone fracture.