Which landmark is used to align the anterior of the tibial implant during planning?

• A. Location: most anterior point of the tibial condyle; Significance: aligns the anterior of the implant during planning stages.
• B. Location: most medial tibial plateau; Significance: alignment.
• C. Location: tidemark; Significance: planning depth.
• D. Location: tibial plateau center; Significance: evaluation.

Answer: (B)

The key idea is that a stable, reproducible landmark on the tibial plateau guides where the anterior edge of the tibial component should sit during planning. The most medial point of the tibial plateau serves as that reference because it lies on the relatively consistent, non-worn portion of the plateau and provides a reliable coronal-plane orientation for the implant. Aligning the anterior edge to this medial plateau point helps match the native anatomy and avoid issues like anterior overhang or misalignment.

The most anterior point of the tibial condyle is more variable and can be affected by osteophytes or resection differences, making it a less dependable guide for anterior alignment. The tidemark marks cartilage-bone boundary and is more relevant to planning depth of resection than to anterior orientation. The center of the tibial plateau can be used for general evaluation, but it doesn’t provide as consistent a reference for aligning the anterior edge as the medial plateau point.