Oblique popliteal ligament

The oblique popliteal ligament (OPL) is a large ligamentous structure of the posterior knee and one of the five components of the posteromedial corner (PMC). It mainly prevents hyperextension in the knee and in addition it is thought to prevent excessive external rotation .

Gross anatomy

It is a broad, flat ligament of the posterior knee joint, overlying the posterior joint capsule with a diagonal course at an angle of ca. 30° in relation to the knee joint . There are significant variabilities in shape as well as attachments, although main insertions and course seem to be relatively stable . Band-shaped, Y-shaped, Z-shaped, trident shaped and complex shaped forms have been described .

Attachments

Medial insertions are a lateral expansion of the semimembranosus tendon and/or the posterior margin of the posteromedial tibia and as well as the posteromedial joint capsule and the capsular arm of the posterior oblique ligament

Lateral insertions are the meniscofemoral portion of the joint capsule, the fabella if present and the lateral head of the gastrocnemius muscle and the plantaris muscle .