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Persona The Personalized Knee
Surgical Technique
Alignment Rod with Coupler
00-5785-080-00
Alignment Rod
00-5785-079-00
MIS Spacer/Alignment Guide
00-5983-070-10
Spacer Block Technique
(cont.)
Balance Flexion and Extension Gaps
Technique Tip:
Prior to addressing flexion/
extension imbalances, make sure that desired
varus/valgus alignment has been attained.
Technique Tip:
If femoral or tibial recuts are
performed subsequent femoral finishing and tibial
finishing steps need to be repeated to provide for
proper provisional and component fit.
With the knee in extension, attach the alignment rod
to the alignment rod with coupler. Check ligament
balance and limb alignment in extension. Refer to
Figure 105 for potential solutions for flexion/extension
mismatches.
1. If a knee is too tight in both flexion and extension,
resecting additional tibial bone or reducing the
height of the tibial bearing may be sufficient to
balance the construct.
Figure 105
2. If the knee is tight in flexion but acceptable in
extension, three options exist. One option is to
release the PCL either by island osteotomy or
ligament release, both of which lengthen the
ligament. If the PCL is absent, change constraint
to MC or UC. A second option is to cement
the femoral component distal to the bone cut.
This augmentation with cement distally fills the
extension space when used with a thinner tibial
bearing. The third option is to downsize the femoral
component.
3. If the joint is loose in extension and tight in flexion
one option is to use a smaller sized femoral
component possibly with a thicker polyethylene
component.
4. If the joint is acceptable in flexion but tight in
extension, several options exist. One is to release
the posterior capsule from the femur. Another
alternative is to resect more distal femoral bone.
This moves the femoral component proximally on
the femur at the expense of elevating the joint line.
Appendix B
(cont.)
Extension
Flexion
Tight
OK
Loose
Tight
1
2
3
OK
4
5
6
Loose
7
8
9
