The main purpose of this thesis project is the analysis of fixation device on a bone fracture. This device is a osteosynthesis screw called Variable Fixation Locking Screw (VFLS). The variable fixation effectiveness is tested in clinically relevant fracture patterns and it is compared with a standard one. The VFLS has a polymeric sleeve characterized by a specific degradation profile over time in order to allow micro-movement during the healing process of the bone fracture. The first step of this project was to validate the femur model, with no pathological condition, carried out in the previous work. Afterwards, the fracture gap has been reproduced and the model has been assembled with plate and screws.