[Stress analysis of the femur after osteosynthesis of a trochanteric fracture using the finite element method].

A stress analysis of the femur was performed in cases of the trochanteric fracture using the two-dimensional finite element method after osteosynthesis with the Ender nail, Jewett nail, AO angle plate and compression hip screw and the dynamic characteristics were discussed. Following results were obtained. (1) The Ender method makes maximum principal stress in the trochanter relatively small compared to the other methods. It also makes stress distribution of the femoral shaft rather stable. (2) The Ender method makes maximum extreme fiber stress in the device the largest compared to the other methods. (3) In the cases with weak abductor muscular force toward a fractured part, the Ender method is rather safe. In the cases with too strong abductor muscular force toward a fractured part, breaking of the device may occur. (4) Insertion of the Ender nails into the greater trochanter is effective in cases with large moment centering inside a fracture, as in a reverse intertrochanteric fracture.