Fig. 3

Assessment of patellofemoral alignment on a skyline view radiograph with the knee in 30° of flexion. a Lateral patellar tilt, defined as the angle formed by the line passing through the maximum width of the patella and the tangent to the anterior apices of the medial/lateral femoral condyles. b Lateral patellar shift (P–P’/C–C’), defined as the value obtained by dividing the distance from the perpendicular line of the patellar lateral margin to the apex of the lateral femoral condyle (P–P’) by the distance from apices of the medial and lateral femoral condyles (C–C’) with tangent to the anterior apices of the medial/lateral femoral condyles as the baseline