Imaging of the anterior cruciate ligament

Figure 9 Magnetic resonance knee in partial flexion. Volunteer, 31-year-old man with no history of injury and clinical instability. Sagittal intermediate-weighted magnetic resonance image in full extension. A: And 30 degree of knee flexion; B: Demonstrates the usefulness of knee flexion. When the knee is extended, sagittal image shows features suspicious of an anterior cruciate ligament (ACL) tear. When the knee is flexed, a gap (black arrow) is clearly present confirming the presence of an ACL tear.