- Discussion:
- it is not a separate ligament but is condensation of fibers of origin of popliteus and helps form the arcuate complex:
- arcuate ligament is a Y shaped condensation of fibers that courses from the fibular head, over the popliteus, to
insert on the posterior capsule;
- spans junction between popliteus & its tendon from fibula to femur in the postero-lateral aspect of knee;
- lies just behind LCL;
- it lies between 2 laminae of capsule, which are always separated by the inferior geniculate vessels;
- medial limb of the arcuate ligament joins fibers of oblique ligament;
- it is firmly adherent to the underlying musculotendinous junction of popliteus;
- both arcuate and fabellogibular ligaments insert on apex of fibular styloid;
- both ligaments ascend vertically to attach to lateral head of gastrocnemius,
- they are joined by posterior termination of oblique popliteal ligament;
- absence of arcuate ligament:
- ligament thickness is greatest in knees lacking a well-defined fabellofibular ligament;
- when fabella is large, there is no arcuate ligament & fabellofibular ligament is robust;
- when cartilagenous fabella is present both fabellofibular ligament & arcuate ligament will be present but smaller than normal;
- both ligaments are present in 2/3 of patients
Chronic posterolateral rotatory instability of the knee.