Anterolateral ruptureofpopliteal cystsin rheumatoid arthritis

Popliteal cystsoccur commonlyinboth normalandarthritic knees. Mostcystsare formed bydistension ofthemedialiy situated semimembranosus bursa. Popliteus bursa distension occursuncommonly as alateral popliteal cyst.Two cases ofruptureoflateral cystswhichproduced symptomsrelated tothe anterolateral lowerlegare reported. The difficulty ofdiagnosing thecondition because ofthisunusual siteofinflammation and subsequent management problemsare discussed.