The primary signs of Complete anterior cruciate ligament tear include abnormal interruption, orientation or non-recognition of the ligament. The most important of the secondary signs is the bone contusion, many other secondary signs may include anterior translation of the tibia, meniscal injury as well as a joint effusion. The horrible triad of the knee includes torn anterior cruciate, medial collaterals ligaments together with torn posterior horn medial meniscus.
Both horns are triangular in shape and characterized by very well defined outlines.
The posterior horn is always bigger than the anterior horn. If the meniscus demonstrates abnormal shape, that may be interpreted as a meniscal tear or you should ask about the history of partial meniscectomy.
Bucket handle tear is a displaced horizontal tear. On coronal images, if there are more than two structures in the intercondylar notch: the anterior and posterior cruciate ligament, that will be a displaced meniscal fragment.