35
Ligament Balancing Manipulations
SCENARIO
MANIPULATION
Balance is loose in the
medial compartment in
flexion
Internally rotate the femur implant to
balance gap in the medial and lateral
compartments
Balance is tight in the
medial compartment in
flexion
Externally rotate the femur implant
to balance gap in medial and lateral
compartments
Balance is loose in the
lateral compartment in
extension
Plan with the lateral gap, if not
performing medial collateral ligament
release at this stage, in order to balance
the medial and lateral gap in extension.
Move the femur component inferior in
extension, to tighten the gap presented.
Balance is tight in the
lateral compartment in
extension
Plan with the lateral gap, if not
performing lateral collateral ligament
release at this stage.
Move the femur component superior
in extension, to loosen the extension
space.
The medial and lateral
compartments are not
balanced in extension
The component default rotation in
varus/valgus is 0 degrees to ensure a
perpendicular distal cut with respect to
the femur mechanical axis.
To balance the medial and lateral space
in extension, recollect ligament stress
in extension, after performing medial
collateral ligament release.
Figure 54.
Based on the extension ligament laxity collection (left), the
gap graph in extension will show medial-lateral difference in gaps
(right). To balance medial-lateral gaps, the user may perform ligament
release in the tighter compartment, and re-collect stress information,
or plan with the looser compartment space.
Figure 55.
After performing ligament release, the stress information
is recollected in extension, and the respective change is observed
in the Gap Planning screen.
7
Implant Planning - Soft Tissue Balancing
