Fig. 4From: Differences between native and prosthetic knees in terms of cross-sectional morphology of the femoral trochlea: a study based on three-dimensional models and virtual total knee arthroplastySulcus height (H) as a key geometric feature of the patellofemoral articular surface. In each case, the line describes the overall profile of the patellofemoral articular surface, characterized by the deepest point in trochlear groove (a; midpoint of the line) and the highest point on each condyle facet (b, c; outer points of the line). See Fig. 4a for an explanation of each parameter. a 0° cross-section; b 45° cross-section; c 90° cross-sectionBack to article page