"Bone bruises" of the knee: a review

Magnetic resonance (MR) imaging is often used to assess the location and degree of ligamentous or cartilage damage in the knee following acute traumatic injury. Occasionally, these studies will also document abnormal signal within the adjacent subchondral bone. These "bone bruises" are considered incidental findings by some, while others suggest possible clinical significance. The purpose of this paper is to review the literature and consolidate current thinking on the radiographic characteristics, classification, histopathology and natural history of bone bruises.