Baker's cyst is a distention or enlargement of the gastrocnemius-semimembranosus bursa toward the popliteal fossa which is usually associated with intra-articular pathologies. Rupture or dissection of the Baker's cyst results in extravasation of the cyst content into the calf within intermuscular space under the fascia. This clinical entity, also called pseudothrombophlebitis, is a self-limited condition that usually resolves with supportive treatment. However, in patients using anticoagulants, excessive hemorrhage may cause compartment syndrome in case of cyst rupture. Early diagnosis of compartment syndrome is the most important step in preventing permanent disability. Therefore, compartment syndrome should be kept in mind and ruled out in a patient with pseudothrombophlebitis syndrome under anticoagulation therapy.
Keywords: Baker's cyst; compartment syndrome; popliteal cyst; rupture.