34
Ligament Balancing Manipulations
SCENARIO
MANIPULATION
Balance is tight
in extension
and flexion
Move tibial component inferior and/or
reduce thickness
Balance
is loose in
extension and
flexion
Move tibial component superior and/or
increase poly thickness
Balance is tight
in extension
and loose
in flexion
Move femoral component superior. Increase the
femoral component size.
-OR- reduce femoral component flexion
Balance is
tight in flexion
and loose in
extension
Downsize the femoral component, or move it
anterior.
NOTE: The femur implants are anterior
referenced. Upsizing or downsizing the
components does not change the anterior cut
from the plan, unless the component is moved
by the user.
NOTE: Exercise caution when anteriorizing or
posteriorizing the femur component as it would
affect the anterior transition of the component on
bone, and evaluate for notching.
Move the femur component inferior to tighten the
extension gap.
-OR- Increase posterior slope of tibial component
Figure 52.
Adjusting the tibia component in the superior/inferior
direction will adjust the gap in both flexion and extension (left: before
movement; right: after moving tibia superior).
Figure 53.
Adjusting the femur component in the extension state,
(left side planning windows) in the superior inferior direction will
adjust gap in extension (TOP: before movement; BOTTOM: after
moving femur inferior in extension).
7
Implant Planning - Soft Tissue Balancing
