Ruptured Baker's cyst producing a pseudothrombophlebitis syndrome

Description: A36-year-old woman presented with sudden onset of calf pain which became more severe over 48 hours. Several months previously she had undergone surgery for disrupted cruciate ligaments. On physical examination the calf was hot and swollen and the patient was running a low-grade fever. Deep venous thrombosis was suspected. However, the presence of a joint effusion was also noted and it was considered important to exclude the presence of a joint infection. Approximately 25 mL of blood-tinged synovial fluid was aspirated. Contrast medium was then injected. The lateral view of the knee after injection of contrast medium demonstrated a large partially opacified cavity in communication with the knee joint, extending into the posterior aspect of the upper calf.
Musculoskeletal case 11. Ruptured Baker's cyst producing a pseudothrombophlebitis syndrome. Munk PL, Lee MJ, Marchinkow LO. Can J Surg. 2000 Aug;43(4):255, 310-1.