Robot-assisted invasive orthopaedic surgery

Changes in orthopaedic practice have led to an increased reliance upon fluoroscopic image guidance during internal fracture fixation (osteosynthesis) procedures. The resulting complexity of surgical techniques, and concerns over X-ray radiation exposure levels to orthopaedic surgeons, has prompted the introduction of new technologies into the operating room with the aim of improving the precision, repeatability and radiation safety of existing surgical procedures. The generic vision-guided robotic system for orthopaedic applications described in this paper is typical of this trend. In order to satisfy the stringent safety requirements of robotic-assisted surgery, the mechatronics design philosophy has been applied to the system. A purpose built manipulator has therefore been manufactured, which when interfaced to an existing C-arm unit allows a drill-bit guide to be automatically aligned with an intra-operatively planned drilling trajectory. Manual completion of the drilling stage can then be performed by the surgeon. The preliminary findings of an ongoing study into the potential for an invasive application of such a system, through the use of an actuated drilling unit incorporating a novel use of force feedback, are also presented. Initial results indicate that force feedback could play a major role in the safety protocol of such an invasive system.