STRESS AND STRAIN DISTRIBUTION WITHIN THE INTACT FEMUR - COMPRESSION OR BENDING

The aim of this research was to test the hypothesis that the intact fe mur is loaded predominately in compression. The study was composed of two parts: a finite element analysis of the intact femur to assess if a compressive stress distribution could be achieved in the diaphyseal region of the femur using physiological muscle and joint contact force s; a simple radiological study to assess the in vivo deflections of th e femur during one legged stance. The results of this investigation st rongly support the hypothesis that the femur is loaded primarily in co mpression, and not bending as previously thought. The finite element a nalysis demonstrated that a compressive stress distribution in the dia physeal femur can be achieved, producing a stress distribution which a ppears to be consistent with the femoral cross-sectional geometry. The finite element analysis also predicted that for a compressive load ca se there would be negligible deflections of the femoral head. The radi ological study confirmed this, with no measurable in vivo deflection o f the femur occurring during one legged stance.