UMEM Educational Pearls

Category: Orthopedics

Title: Baker Cyst

Keywords: Popliteal cyst, knee swelling (PubMed Search)

Posted: 9/26/2015 by Brian Corwell, MD
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Most common mass in popliteal fossa

Incidence 10 to 58%

Intra-articular pathology results in flow of synovial fluid from the joint into the bursa, forming a cyst

Association with concomitant intra-articular disorders 94%

Possible pathology - Meniscus, ligamentous, arthritis, other osteochondral defects

In children this is not a pathologic finding

Symptoms - Posterior knee bulging, posterior tightness/stiffness esp. with knee flexion

Ultrasound - 100% sensitive/specific


Tx: Refer for ultrasound guided aspiration, fenestration and steroid injection


Smith, Lesniak et al. 2015 Treatment of popliteal cysts with ultrasound-guided aspiration, fenestration and injection: long term follw-up