Popliteus Tendon Bursa

bursa musculi poplitei

The popliteus bursa lies between the popliteus tendon and the posterolateral tibial plateau articular margin, extending superiorly beneath the lateral meniscus at the popliteal hiatus (the gap in the posterior capsule where the popliteus tendon exits). It usually communicates with the knee joint and with the proximal tibiofibular joint, making it an important conduit for fluid communication in lateral knee pathology.

Region: Knee

Clinical Relevance

Clinical Notes

The popliteus bursa commonly communicates with the knee joint through the popliteal hiatus, meaning that fluid from a knee effusion fills the popliteus bursa. On MRI, fluid tracking along the popliteus tendon into the popliteofibular space may be mistaken for a popliteus muscle tear or a lateral meniscal cyst. The popliteus hiatus in the posterolateral capsule is also the portal for posterolateral compartment arthroscopy and for visualisation of the posterior horn of the lateral meniscus through the popliteus recess.

Pathology

Common Injuries & Conditions

Popliteus Bursa Fluid from Knee Effusion Communication

The popliteus bursa communicating with the knee joint through the popliteal hiatus fills with fluid in any significant knee effusion, appearing on MRI as a tubular fluid track along the popliteus tendon into the posterolateral knee; this communication must not be mistaken for a popliteus muscle tear or a lateral meniscal cyst.