Closed surgical techniques used in the internal fixation of fractures (osteosynthesis) have increased the reliance upon fluoroscopic (X-ray) image guidance, as well as increased the complexity of fracture fixation techniques. Concerns over X-ray radiation exposure levels to orthopaedic surgeons and the complexity of these techniques have prompted the introduction of robotic assistance in orthopaedic surgery. A robotic system, incorporating a purpose built manipulator and a machine vision system, based on X-ray image acquisition, is described. Design issues related to safety and sterility requirements are discussed.