The ACL runs through a special notch in the femur called the intercondylar notch and attaches to a special area of the tibia called the tibial spine.The ACL is the main controller of how far forward the tibia moves under the femur. This is called anterior translation of the tibia. If the tibia moves too far, the ACL can rupture. The ACL is also the first ligament that becomes tight when the knee is straightened. If the knee is forced past this point, or hyperextended, the ACL can also be torn.
Ligaments and tendons do not show up on X-rays, but bleeding into the joint can result from a fracture of the knee joint, or when portions of the joint surface are chipped off.Magnetic resonance imaging (MRI) is probably the most accurate test for diagnosing a torn ACL without actually looking into the knee. The MRI machine uses magnetic waves rather than X-rays to show the soft tissues of the body. This machine creates pictures that look like slices of the knee. The pictures show the anatomy, and any injuries, very clearly. This test does not require any needles or special dye and is painless.
Nonvisualization as primary sign of anterior cruciate ligament (ACL) tear. Sagittal image shows complete (or near-complete) nonvisualization of the ACL with ill-defined edema and hemorrhage in the usual location of the ACL in the intercondylar notch. This is a very common presentation of an acute ACL tear. Note: the normal ACL is sometimes poorly seen on low–echo-time (T1 or gradient echo) sagittal images; this usually does not present a problem in interpretation if T2 images and images in other planes are carefully correlated.
The primary signs of an ACL tear include nonvisualization, disruption of the substance of the ACL by abnormal increased signal intensity, abrupt angulation or a wavy appearance, and an abnormal ACL axis. The axis of the ACL is abnormal if it is clearly more horizontal than a line projected along the intercondylar roof (Blumensaat line) on sagittal images. The ACL axis can be quantitated (although the authors have not found this to be necessary); a less than 45° angle of the long axis of the ACL relative to a line parallel to the tibial plateau (the ACL angle) is reportedly sensitive and specific for ACL tear.
Anterior cruciate ligament (ACL) is in the middle of the knee. It prevents the shin bone from sliding out in front of the thigh bone.
ReplyDeleteUp to 80% of the knees will eventually develop a cartilage tear. The smooth Teflon lining of the knee which is known as articular cartilage is often damaged at the time of the ACL tear. If left untreated, this will again progressively wear at the knee, causing an increased rate of osteoarthritis development. ACL tears cannot be healed without ACL tear surgery in Mumbai.