An Integrated Method to Analyze Degenerative Bone Conditions on Transfemoral Amputees

This work proposes an integrated method to analyze, from a kinetic and a clinical perspective, the degenerative condition of the mechanical properties of the femur due to the bone density decrease in patients with transfemoral amputation. A dynamic study of gait was conducted in order to obtain the kinematic and the kinetic variables from both limbs, which then were integrated into a finite element (FE) model of the socket-femur-residual limb system and the intact leg. Such models employed computed tomography (CT) scans of the amputated and the intact leg of all the volunteers for this study. Mechanical properties like the apparent density of the trabecular part and the cortical part of the bone of both legs were determined, as well as the Young's modulus and the tensile yield strength. All these physical and mechanical properties were based on indexes extracted from CT scans, expressed in the Hounsfield (HU) scale. These results may help in investigating correlations to the degenerative condition of the mechanical properties with the bone density alterations and then to establish the possibility of fractures occurrence in the hip joint at different activity levels of the amputee patients.