Fig. 1.

a The acetabulum is reamed with robotic guided navigation with the reamer constrained by a virtual haptic tunnel which prevents the surgeon from going off-line or too deep. The reamer stops if human error is made. The computer screen shows the angle of the reamer which only needs to be within 10° of desired numbers to create the correct hemisphere. The COR superiorly, medially, and anterior-posteriorly is defined and when the reamer achieves the correct COR the robot stops reaming. The robot is seen on the right-hand side of the figure and the surgeon’s hands hold the reamer. b The cup is connected to the robot and directed to the correct inclination and anteversion through a virtual haptic tunnel created by the robot. The computer screen will give the numbers achieved for inclination and anteversion and the haptic tunnel will not allow more than 5° variation from the plan