Imaging of the anterior cruciate ligament

Figure 5 Primary signs of anterior cruciate ligament tear. Sagittal intermediate-weighted images of three different patients showing different patterns of anterior cruciate ligament (ACL) tear. A: Typical appearance of ACL tear at the mid-substance with fibres discontinuity of ACL (arrowheads). Residual stumps on femoral (asterisk) and tibial sides (white arrow) are lax, thickened and increased in signal intensity; B: Chronic ACL tear with absence of normal ACL fibres compatible with complete resorption of fibres. PCL (Curved black arrow); C: Acute high grade intrasubstance tear as characterized by thickening and oedematous change of ACL fibres which show increased signal intensity (white arrows). The fibres are still in continuity suggestive of partial ACL tear.