Illustrates the proposed landmark relationship. Colored attachment footprints follow the bone surface. Hash marks show 1 mm intervals to the original surface on each side; wear does not redefine that reference. Their anatomical placement is illustrative.
Match the posterior slope.
Adjust independently, then match the simulated native slope.
Sweep the mounted stylus anterior to posterior. Adjust the guide until the tip follows the preserved surface throughout the sweep.
Reference assumptions
Grades 1–4 are the illustrative cartilage progression used in this teaching model, not a clinical grading scale. Bony wear is controlled separately; its four levels are illustrative rather than clinical severity thresholds.
The 9 mm relationship uses the upper edge, nearest the joint, of each attachment. The attachment locations have not been measured in this model.
The base of the tibial spines is another described reference; this demonstration focuses on these peripheral attachments.
Stylus shape is reconstructed from the supplied visual references, not instrument CAD. The stylus requires preserved cartilage. A worn defect is not a substitute for that reference. Side-on assessment is shown as a separate method; neither establishes a validated patient-specific slope here.
Persona tibial tray: supplied E Right CAD. Polyethylene is an MC-inspired visual reconstruction: deeper medial socket, shallower lateral track, and raised anterior medial lip. It is not manufacturer bearing CAD. Zimmer Biomet MC design reference. The illustrative polyethylene is fitted to a 9 mm total stack at the preserved reference. The illustrated stack is — mm at the preserved reference. Metal CAD dimensions are unchanged. The cut depth follows that stack; the saw slot, bone cut and tray underside use one plane. This is a geometric illustration, not an instrument setting or validated surgical plan.