Knee: Anatomy: Patellar ligaments and tendons

Medial patellofemoral ligament:
Most important stabilizing structure of the patella preventing lateral subluxation. Low-signal-intensity band extending from the superior pole of the patella to the adductor tubercle. On axial images, located just deep to the vastus medialis obliquus muscle

Proximal lateral patellofemoral ligament:
To lateral intermuscular septum

Distal lateral patellofemoral ligament:
To femoral insertion of posterolateral part of capsule and/or lateral head of gastrocnemius

Medial retinalculum:
Arises from midpole of patella. Located just distal to the MPFL. At the level of the medial retinaculum, the vastus medialis obliquus muscle should no longer be visualized

Patellar tendon:
Thick band of fibrocartilagenous tissue. From anterior surface of non-articulating inferior pole of patella to anterior lip of tibia and tibial tubercle. Oval or biconcave on cross section. 3-6mm thick and 10-15mm wide. Proximal and distal attachment relatively avascular. Low signal on all sequences. Triangular high signal at patellar attachment seen in 3/4th of normals. Echogenic parellel fibrils on long axis, punctate on cross section

Ligamentum mucosum (infrapatellar plica):
Anterior to ACL
From superior condylar notch
May be seen distinct from ACL