Illustrates the proposed landmark relationship. Colored attachment footprints follow the bone surface; their anatomical placement is illustrative.
Match the posterior slope.
Adjust independently, then match the simulated native slope.
Tip contacts a preserved medial cartilage point. Rotate the guide about that contact; one point alone does not determine slope.
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 9 mm landmark relationship is separate from the assembly thickness. The current illustrated stack is approximately — mm at the preserved reference, not 9 mm. 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.