Knee Replacement

Most total-knee replacements depend on a jig system to guide bone sawing. The placement of the jig is based on the surgeon's visual cues from the exposed bone surfaces. These inaccuracies can produce patellofemoral pain and limited flexion in 40% of the patients when conventional approaches are used.^[78] Displacements as small as 2.5 mm can produce a 20-degree alteration in the range of motion of a joint.

Robotic surgical assistants have been developed to increase the accuracy of prosthetic joint alignment. For the robot to recognize specific landmarks, the pelvis and the ankle must be fixed to the surgical table. Osseous material is less likely to deform under pressure and can keep its shape.