Abstract
To examine bony lesions associated with anterior Cruciate ligament (ACL) injuries, magnetic resonance (MR) imaging was performed on 55 knees with ACL injuries. With respect to the period between ACL injuries and MR imaging, the knees were divided into acute (within one month), subacute (from one month to one year) and chronic (over one year) groups, containing 19, 16 and 20 knees, respectively. Occult bony lesions not shown in roentgenography were observed more frequently in the acute group (13/19) than in the other two groups (subacute group, 5/16 ; chronic group, 1/20), located in the lateral compartment of the knee joint. In the acute group, bony lesions had high signal intensity on T2-weighted images and low signal intensity on proton density images. In the subacute and chronic groups, bony lesions were less pronounced and had low signal intensity on T2-weighted images. These findings suggest that bony lesions are frequently associated with and occur simultaneously with ACL injury.
