Ruptured popliteal cyst -- an unusual complication of osteo-arthritis: a case report.

Synovial rupture produces a syndrome resembling acute thrombophlebitis and it is usually seen in patients with rheumatoid arthritis. The interesting feature reported here is the occurrence of popliteal cyst rupture in a patient with no evidence of inflammatory joint disease. It is important to diagnose this condition correctly and to avoid anticoagulant therapy.