Figure 2.

Tibial-based measurements. (A) PA-TA angle. The 2 axial slices described in Figure 1 were fused using PACS software, and the angle between the plateau axis (PA) and tuberosity axis (TA) was measured. (B) GC-TA angle. A line was drawn from the geometric center of the tibial plateau (GC) to the apex of the tibial tuberosity (TA). This apex was defined as the crossing of the medial and lateral tangents to the cortices of the tibial tuberosity. The angle between the line connecting the GC to the TA and the bisector of the medial and lateral tangents of the tibial tuberosity was measured. (C) PA-MT angle. A line was drawn connecting most lateral and medial ends of the patellar tendon insertion to the tibial tuberosity. The midpoint of this line was defined as the midtuberosity point (MT). The angle between the PA and the line connecting the MT to the GC was measured.