Bone bruises of patients with acute traumatic knee injuries, that are not found on simple radiograph, can be found on magnetic resonance imaging (MRI). The purpose of this study is to evaluate the frequency and locations of bone bruises on MRI in acute traumatic anterior cruciate ligament (ACL) or posterior cruciate ligament (PCL) injury.

25 and 19 MRls, in which acute traumatic ACL and PCL injury was pre sent and there was no abnormality in simple radiograph, were reviewed. MRI was taken within 51 days of injury. A bone bruise was determined as a geographic and nonlinear area of signal loss on T1 images and increased signal intensity on T2 images involving the subcortical bone.

In 16 patients with bone bruises and acute ACL injury, bone bruises were found in the lateral compartment of the knee in 15 (93.8%) patients. The most common area was the lateral tibial plateau (11 cases, 68.8%) and the second was lateral femoral condyle (9 cases, 56.3%). In 5 patients with bone bruises and acute PCL injury, bone bruises were found in the lateral compartment of the knee in all 5 (100%) patients. The most common area was lateral tibial plateau (4 cases, 80%) and the second was lateral femoral condyle (2 cases, 40%).

In patients with acute traumatic ACL or PCL injuries the bone bruises are often found on the lateral compartment of the knee, especially lateral tibial plateau and lateral femoral condyle on MRI.