Zimmer Biomet Persona, Surgical Technique, Page: 33 / 72

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Persona
®
Revision Knee System
Surgical Technique
Trial Reduction
(cont.)
Flexion and Extension Gap Analysis
With all provisional components in place, check
ligament stability in extension, in 30, 60, 90 and 120
degrees of flexion with the patella reduced. Check for
posterior osteophytes. Attempt to distract the joint in
flexion. Reference the Flexion and Extension Decision
Matrix above to help recreate a stable joint. Perform a
range of motion to check component positioning and
joint stability.
Figure 80
Flexion and Extension Decision Matrix
Tight in Extension Stable in Extension Loose in Extension
Tight in
Flexion
Decrease tibial bearing thickness Downsize femur
Use distal femoral augments and
thinner tibial bearing
Resect more tibia
Use distal femoral augments and
thinner tibial bearing
Downsize the femur and use thicker
tibial bearing
Offset the femur anteriorly and use
thinner tibial bearing
Offset the femur anteriorly and use
thicker tibial bearing
Stable in
Flexion
Resect additional distal femur Gaps balanced
Use distal femoral augments
Downsize femur and use thicker
tibial bearing
Loose in
Flexion
Resect distal femur and use plus
femur
Use a plus femur
Increase tibial bearing thickness
Add/increase tibial augments
Resect distal femur and use thicker
tibial bearing
Use distal femoral
augments and plus femur
If a plus femur is required to fill the flexion space,
remove the TASP and the femoral provisional
construct, disassemble the femoral provisional from
the stem extension provisional and replace with the
same size plus femoral provisional. The plus femoral
components provide an addi3 mm of flexion
fill compared to the corresponding standard femoral
components (Figure 80). No new cuts need to be
made for like-sized components. Insert the plus
femoral provisional construct into the femoral canal
and repeat the range of motion checks.
+ 3 mm