Proposed Geometrical Tool for Cases of Laterally Adapted Tibial Tubercle during Total Knee Replacement

Table 1

Tibial component alignment in three planes.

Plane of alignment	Anatomical correct alignment	Technical concept to ensure the alignment
Sagittal	Tibial plateau slopes posteriorly 7°–10°	The cutting block has a slope of 7° and the guide rod should be one finger wide from the leg shin proximally and two fingers distally
Coronal	Patella tracked with the tibial tuberosity, leg shin, and midtalar point (MPTA is 90°)	The guide should be aligned to these three landmarks (medial third of tibial tuberosity for best patellar tracking [1], leg shin for a cut that is perpendicular to the tibial mechanical axis, and midtalar point [2])
Transverse	The joint line is the obvious landmark	Shifting the block vertically until the cut on the most defected side (right or left) is 2 mm