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for partial replacement of the joint. That means if 1 out of every 5 of your joint
replacement patients isn't at least considered for a unicompartmental proce-
dure, your surgeons are replacing too many total knees. Robotic-assisted sur-
gery can help flip those percentages around by making uni knees much easier
and more reproducible to perform.
All patients who are candidates for partial knee replacements can have the
procedure done robotically. There are 2 main options to choose from. One
requires a pre-op CT scan of the knee, which is used to generate a 3D model of
the joint's anatomy. During the intraop planning phase, surgeons can assess the
kinematic balancing of the knee's ligaments and optimize implant positioning
before any bone preparation is performed. The robotic platform's camera cap-
tures the pose and applies it to the 3D model, which surgeons use to plan the
precise placement of implants in the joint, where they'll achieve the desired
alignment and stability. If the implant is ultimately placed in the exact position
indicated on the model, the knee's ligaments will be balanced and the implants
will be sized correctly. That means the implants' contact area will be placed
along the joint's centerline, so premature wear and loosening can be avoided.
On the day of the surgery, the surgeon places optical arrays in the femur and
tibia near the knee joint. The robotic system tracks the arrays in real 3D space
and in real time. Once the arrays are placed and the bone is registered with the
system, the surgeon moves the platform's robotic burr into the joint. The burr is
constrained by haptic boundaries, so it can shave away bone only in the loca-
tions indicated on the model created during the pre-op and intraop planning
phases, meaning the implant will fit precisely where the surgeon intends.
Another robotic-assisted system employs a handheld smart instrument that
uses haptic boundaries to guide the surgeon to areas of the bone in the joint that
need to be shaved. Much like surgical navigation systems, the instrument is com-
pletely dependent on the surgeon inputting data points — not on actual patient
anatomic data taken from a CT scan — so it might not be as accurate as a true
robotics system. However, it's also approximately half the price and is a vast
