Abstract
Femoral neck fractures are increasing with the progress of an aging society. Problems of conventional reduction methods such as operation's burden, radiation expose and uncertainness of a fracture condition are previously discussed. We have developed a robot to assist the operation of fracture reduction to solve these problems. In this report, we present the fracture reduction system for direct reduction methods, which is more precise than indirect reduction methods. An operation mode of a robot that can control a pose of the bone fragment according to the bone coordination is proposed and is evaluated.