Anterior Cruciate Ligament Rupture | Figure 1

Anterior Cruciate Ligament Rupture

Image description
Sagittal proton density (image 1) and T2-weighted MRI (image 2) show disruption of the anterior cruciate ligament (arrow). A small knee joint effusion is present.

Teaching point
Anterior cruciate ligament rupture is characterized on MRI by fiber discontinuity, abnormal signal within the ligament, and loss of the normal taut orientation. These injuries most commonly occur through a noncontact mechanism involving pivoting, sudden deceleration, or hyperextension of the knee. Associated findings may include joint effusion, bone contusions of the lateral femoral condyle and posterolateral tibial plateau, and injury to secondary stabilizing structures, which can help support the diagnosis when direct ligament findings are subtle.

Diagnosis added by author
Anterior Cruciate Ligament Rupture

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