Fig. 4
From: Imaging evaluation of patellofemoral joint instability: a review
Fat-saturated proton density-weighted magnetic resonance images demonstrating the measurements of the indices to assess patellar lateralization. a Congruence angle (∠θ). b Patella–lateral condyle [A/(A + B)] and lateral shift (A/B). c Bisect offset ratio [A/(A + B)]. d Lateral patellar displacement (distance MF–MP). e Patellar displacement (distance TG–P). f Lateral patellofemoral length (length A) and tangent offset (A/(A + B)). g Lateral patellar edge (length A). h Patellofemoral axial engagement index (A/B)