18
Figure 20.
Ankle Center
Using the point probe, input the locations of the
medial and lateral malleoli points by identifying
the most prominent portion (Figure 20). Ensure
that the point probe is visible throughout the point
collection. If the probe is not visible, check that
the tracking spheres on the point probe array are
not overlapping (in front, or behind) the tracking
spheres on the tibia tracker array.
Femoral Condyle
There are four femoral landmark points to collect.
These points are to be used as visual references
during Implant Planning (Section 6). It is important
to take care to understand where these points
are taken on the patient’s bony anatomy so that
they may be referenced properly during planning.
Using the point probe, collect the following
(Figures 21-24):
•
Knee Center
Mark the center of the knee, which will be
referenced as part of the HKA (hip-knee-ankle)
weight-bearing axis. This point collection, along
with the hip center collection, defines the femur
mechanical axis.
•
Most Posterior Medial Point
Hyperflex the leg to access the most posterior
points on the femoral condyle, marking the
inflection point as the condyle curves posterior.
This point is used in conjunction with the anterior
notch point and the most posterior lateral point for
initial sizing of the implant component.
Figure 22.
Figure 21.
4
Registration
