Native height restored. This reference knee moves from 0° to 130°.
Green outline: native tibial surface, always visible. Slope and bearing thickness stay fixed.
About this illustration
Leaving more tibia raises the same tray and bearing, reducing space in both extension and flexion. Taking more tibia with unchanged bearing thickness lowers the reconstruction and increases space in both flexion and extension. The filled green surface and its outline show the approved native tibial cartilage geometry, held fixed as the reconstruction moves. It remains visible through the implants for comparison.
The 0–130° baseline and progressively restricted endpoints are teaching examples, not predicted patient outcomes. For this animation only, each extra millimeter adds 5° to the extension limit and subtracts 10° from the flexion limit. For over-resection, the example extends that authored relationship to −10° extension and 150° flexion at 2 mm more resection. These values are authored, not a measured clinical conversion. Greater laxity does not guarantee greater maximum flexion, and motion beyond 130° is not inherently abnormal; here it illustrates motion beyond this reference knee. A thicker bearing could compensate for additional resection, but bearing thickness is held fixed in this comparison. Ligaments show a subtle authored slack-to-taut transition, with bone attachments preserved. The model does not calculate tissue forces or a mechanical stop.
Actual motion depends on preoperative stiffness, soft tissues, component geometry and position, and other factors. Restoring tibial height does not guarantee 130° flexion.
Zimmer Biomet · Balancing flexion and extension gapsThis revision-system guidance supports the gap-balancing principle; it does not validate the Persona animation’s degree limits. The bearing is the approved MC-inspired illustration.
Persona FuZion · Balancing matrix describes a thicker bearing as an option when both flexion and extension are loose; it does not establish the degree limits shown here.