MRI of the patellofemoral joint.

In routine MRI of the knee, less attention frequently is paid to the patellofemoral joint and its surrounding structures than to the menisci and ligaments. This article reviews MRI of common abnormalities of the anterior aspect of the knee. Chondromalacia patellae, pathological softening of the patellar cartilage, can be diagnosed with reasonable accuracy with MRI using standard sequences. Abnormalities of alignment can be assessed grossly on static images, but more sophisticated evaluation of patellofemoral tracking requires the kinematic technique. Other traumatic or overuse injuries involving the extensor mechanism of the knee, such as the quadriceps and patellar tendons, are also reviewed briefly.