Magnetic Resonance Imaging of the Patellofemoral Joint

Patellofemoral pain is common in both athletic and nonathletic individuals. It is observed in 15%–33% of the young active group and approximately in 21%–45% in adolescence. Among athletes, men tend to present with more patellofemoral injuries than women. In the nonathletic population, women and young individuals more commonly present with patellar disorders. Many static and dynamic internal derangements of the patellofemoral joint in these patients lead to various secondary imaging findings. Because of the excellent contrast resolution and the ability to directly obtain images in three planes, magnetic resonance imaging is the preferred technique for evaluating cartilage abnormalities, instabilities, and contiguous soft tissue injuries of the patellofemoral joint. This review defines the magnetic resonance imaging of common abnormalities of the patellofemoral joint. Chondromalacia patellae can be diagnosed with high accuracy using magnetic resonance imaging. Abnormalities of the patellofemoral alignment can be grossly assessed on static images; however, more sophisticated evaluation of patellofemoral tracking requires the kinematic technique. Traumatic injuries of the patellofemoral joint, such as traumatic patellar dislocation, traumatic injuries of quadriceps, and patellar tendons, are also reviewed.