Trial reduction
The purpose of the trial reduction is to check
the radius of movement, patella guidance
and the tension of the soft-tissue mechanism.
The tibial trial together with the trial stem
(depending on the last reamer diameter and
depth) are inserted with using the impactor.
Note
It is possible that the same trial stem is re-
quired on the femur and on the tibia. In this
case, for the femoral trial fit a shorter trial stem
with the same diameter or one of equal length
with a smaller diameter or do not fit a trial
stem at all.
The femoral trial together with the trial stem
(depending on the last reamer diameter and
depth) are inserted with using the impactor.
Note
When using blocks, there are appropriate
block trials available (5 mm, 10 mm and
15 mm), which are fixed to the tibial trial or
femoral trial.
Attach the appropriate tibial insert trial, which
has been previously defi ned with the spacer,
onto the rotation peg of the femoral trial in
the 90° fl exed position and insert it into the
tibial trial by hand.
The implant fi t, the kinematics of the knee
joint, and patellar function are checked.
At this point, a defi nitive decision should
be taken regarding patella replacement
(see instructions on page 41 ff).
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