The main purpose of this thesis work is the analysis of a new bone fracture device that allows variable fixation treatment. It is an osteosynthesis screw, called Variable Fixation Locking Screw (VFLS), which aims to ensure variable behaviour of the fixing structure according to the different needs of the bone tissue during the healing process. The variable fixation locking screw is characterised by a polymeric sleeve on the screw rod made of a material with a specific degradation profile over time. In this way, in the initial steps, it will tend to limit movements by acting as a standard locking screw, ensuring contact with the bone both proximal and distal to the plate.