Imaging of extra-articular injuries of the knee.

Imaging of the extra-articular structures of the knee is important, particularly in overuse injury. Close attention needs to be paid to these areas on magnetic resonance (MR) imaging because misdiagnosis of extra-articular pathology is common, and these lesions are important to consider when planning management. This article details the clinical and radiological aspects of extra-articular injury of the knee with particular emphasis on MR and ultrasound imaging.