The autonomous
robot is currently
used only for hip
replacements; howev-
er this platform will
soon be available
after it receives FDA
approval for knee
arthroplasty. Before
the knee replacement
operation, the sur-
geon maps and regis-
ters the location of the joint bones to the robotic system by placing
a motion sensor near the joint and pressing a button to bring the
robotic arm into the surgical field. The arm perfectly mills the bones
to the shape of the implant based on the pre-op plan designed by the
surgeon. For that reason, automated robots will likely be involved in
the development of the next generation of patient-specific implants.
The other type of robotic platform, which is based on haptic guid-
ance, can be used on hips or knees. Surgeons use a similar registration
process to align the robotic arm with the joint before pushing the arm
through a preprogrammed cutting plane. Optical trackers on the joint
and robotic arm are used to synchronize these parts. Every time the
surgeon moves, the joint moves in perfect synchrony. But if the sur-
geon moves too fast, the robot shuts down as a safeguard.
Robotic-assisted surgery doesn't necessarily make joint replace-
ments simpler. Surgeons must virtually plan and map the entire sur-
gery based on pre-op scans of the patient's joint anatomy before they
start the actual surgery. Setting up a robotic platform extends the nor-
mal time of surgery by 10 to 20 minutes; however, the technology cer-
4 8 • O U T PA T I E N T S U R G E R Y M A G A Z I N E • A P R I L 2 0 1 8
• PERFECT FIT Properly aligned implants will replicate the joint's normal biome-
chanics.
