Joint Orientation Lines\Joint Lines

The orientation of the hip joint in the frontal plane can be described by 'Proximal Femoral Joint line' as a line joining the tip of greater trochanter and the femoral head center (Fig. 4a)

The orientation of the hip joint in the frontal plane can also be alternatively described by 'Femoral Neck Line' as a line joining the femoral head center and mid-diaphyseal width of the femoral neck (Fig. 4b)

The frontal plane knee joint line of distal femur or 'Distal Femoral Joint Line'  is drawn as a line tangential to the most distal point on the convexity of each of the two femoral condyles (Fig. 4c)

The frontal plane knee joint line of proximal tibia or 'Proximal Tibial Joint Line' is drawn across the flat or concave aspect of the subchondral line of the two tibial plateaus (Fig. 4d)

The frontal plane ankle joint line or 'Distal Tibial Joint Line' is drawn across the flat subchondral line of the tibial plafond in either the distal tibial subchondral line or for the subchondral line of the dome of the talus (Fig. 4g)

In the sagittal plane, Proximal Tibial Joint Line is drawn along the flat subchondral line of the tibial plateaus (Fig. 4e)

In the sagittal plane, Distal Femoral Joint Line is drawn as a straight line connecting the two points where the femoral condyles meet the metaphysis of the femur (Fig. 4f)

In the sagittal plane, Distal Tibial Joint Line is drawn from the distal tip of the posterior lip to the distal tip of the anterior lip of the tibia (Fig. 4h)