Right knee of the same subject at baseline (A) and after 48 months (B) as shown by sagittal intermediate-weighted fat-saturated turbo spin-echo sequences (FOV, 160mm; slice thickness, 3mm; gap, 0mm; flip angle, 180°; TE/TR, 30/3200ms; acquisition time, 4.7mins). A—Hyperintense signal alteration of the SPFP (arrow) and early degenerative changes of the patellar cartilage shown as hypointense signal inhomogeneity (dashed arrow). B—The same subject showing patellofemoral cartilage degeneration after 48 months including an extensive subchondral bone marrow lesion (arrowheads) and a full thickness cartilage fissure in the patella (dashed arrow).