Robotic Long Bone Fracture Reduction

Medical robotics is still a relatively new field with researchers and companies all adopting various styles and techniques to solve the challenges faced. This chapter outlines one unique approach to the development of a medical robot for the reduction of broken femurs. Fractures are common injuries, for example in adults over the age of 65 it is reported that 87% of falls results in a fracture (Canale & Campbell, 2003). This has lead to the development of focused trauma centers having the capability to quickly diagnose and respond with the appropriate treatment action and expertise. However, orthopedics as a discipline is relatively conservative with a large scope for improvement. Often techniques used are controversial and experience of the surgeon is limited as training is difficult. Historically the main drivers for improvements in the tools and methods used have been the large number of injuries during world wars. Development focus was on life and limb preservation while the technology has remained relatively constant. Now there is an opportunity with the increased advancement of technology to look at the processes and overcome problems that previously could not be addressed. Orthopedics has been identified as particularly suitable for robotic applications as bones are relatively rigid structures and imaging techniques allow a computer to locate and register the location of bones. This has lead to the implementation of new medical robotic technologies such as ISS Robodoc for total hip replacement (Kazanzides et al., 1992.) and Acrobot for knee replacement (Jakopec et al., 2003). These systems are commercially available and have been successful in improving the accuracy and overall outcome of surgery. Investigation into long bone fracture reduction in particular has received attention by several groups. Gösling et al. (2005) and Westphal et al. (2006) developed a joystick teleoperated system using a serial robot and carried out preliminary user studies. They showed that the robotic system can achieve precise alignment and reduce intra-operative imaging. Maeda et al. (2005) and Warisawa et al. (2004) also used a serial robot and examined three control modes of manual jogging, power assist and automatic. Graham et al. (2006) previously described a conceptual fracture reduction system including procedure planning assistance and a parallel robot mechanism for reduction, this work is a further development of that. In previous research work many problems are only partially understood and/or solved. For example radiation exposure, fatigue and problems in pre-operative planning remain. To properly determine the needs and focus direction of research it is useful to form the framework in Fig. 1. From this figure the main stakeholders are presented as system O pe n A cc es s D at ab as e w w w .ite ch on lin e. co m