"Bone bruises" on magnetic resonance imaging evaluation of anterior cruciate ligament injuries

Abstract

Magnetic resonance imaging of the knees of 98 con secutive patients with clinically diagnosed anterior cru ciate ligament injuries revealed 47 patients (48%) with focal signal abnormalities consistent with the diagnosis of a "bone bruise." Seventy-one percent of the magnetic resonance images taken within 6 weeks of injury dem onstrated a bone bruise, whereas no scans done longer than 6 weeks after injury showed a bruise ( P < 0.0001). Also significant was the tendency for lesions to be located in the lateral compartment ( P < 0.0001). In the sagittal plane, lesions were most likely to be in the middle third of the lateral femoral condyle and the posterior third of the lateral tibial plateau ( P < 0.0001). In 31 patients evaluated arthroscopically, there was no correlation between the presence or location of a bone bruise and articular alterations or meniscal tears ob served at surgery.