Intra-articular, but extra synovial
Attachments:
Proximal - fossa on posteromedial aspect of lateral femoral condyle, located posteriorly
Distal - fossa anterolateral to anterior tibial spine, between anterior attachments of menisci, Broader and larger than the proximal attachment.
Passes deep to transverse ligament
Parts:
AMB (anteromedial band) - longer and stronger, tightens with knee flexion
PLB (posterolateral band) - shorter, but forms major bulk of ACL; Tightens in knee extension, may show int signal on T1 as it is more relaxed in knee extension
Signal:
Low signal with all pulse sequences
Slightly higher signal than PCL, because the scans are done in extension, which decreases ACL tension compared to that of PCL.
In older people, may show int signal due to eosinophilic degeneration
Configuration:
May show more lax configuration
May contain striations with signal intensity alterations between fibers near its tibial attachment
Courses parallel to the roof of the intercondylar notch
Sagittal:
Best visualized in the oblique sagittal plane3-4 mm thick slicesPrimary plane of ACL analysis
Femoral and tibial attachment are best shown
At tibital attachment, linear int-to-high signal may be seen on T1 due to fat/synovium
Axial and coronal:
Relation of proximal ACL to medial aspect of lateral femoral condyle
