Strength distribution in the tibia.

Stress fracture of a tibia is rarely associated with osteoarthros of the knee joint (gonarthrosis), whereas the present authors experienced a case of tibial stress fracture with high level lateral flail. To make an analysis with the statics of an elastic body, the shape of the tibia was read from a roentgenogram with a digitizer. The bend of a tibia was expressed with curvature (the reciprocal with curvature radius); fracture was expected to occur where the curvature was large. From the analysis, the fracture had occurred near one of the maximums of the curvature when the knee side was fixed and a force was applied to the ankle side --walking situation, e.g. The analysis also has indicated that the tibia would be very weak when the ankle side was fixed--skiing situation, e.g.