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NexGen MIS LPS-Flex Mobile Implant System
Surgical Technique
Step Eight: Check Flexion Gap
Knee in 90° flexion.
Use the spacer/alignment guides
or MIS spacer/alignment guides to check ligament
balance and joint alignment in flexion. Insert the
alignment rod with coupler into the guide and check
the alignment of the tibial resection (Figure 8a).
Then check ligament balance. If necessary insert
progressively thicker spacer blocks until the proper
soft tissue tension is obtained. When using the MIS
flex femoral finishing guide, the flexion gap will be
greater than the extension gap. Position the LPS-Flex
spacer block adapter on top of the spacer block to
simulate the LPS-Flex component posterior condyle
dimension for sizes C-G.
Note:
Do not use the CR-Flex spacer block adapter
since it simulates the CR-Flex component posterior
condyle dimension and will result in inaccurate
representation of the LPS-Flex flexion gap.
Balance Flexion/Extension Gaps
Knee in extension.
Attach the alignment rod to the
alignment rod with coupler. Check ligament balance
and limb alignment in extension.
If the tension is significantly greater in extension than
in flexion, re-cut the distal femur using the appropriate
instrumentation. This will enlarge the extension space.
If the tension is tighter in extension than in flexion,
perform additional ligament releases.
The goal is to create a rectangular and symmetrical
flexion gap between the femur and tibia.
Figure 8a