Surgery revealed mild chondromalacia of the medial femur and an inflamed synovial cyst. Pathology confirmed the diagnosis of a Baker's cyst. In 1877, Baker2 expanded this initial description and the cysts have since borne his name. Intraarticular knee disease also plays a role in the genesis of this cyst in adults.3 The natural history of a Baker's cyst is usually benign, and patients may complain only of minor symptoms. Correction of the intra-articular lesion may bring resolution of the cyst.
Surgical excision is indicated primarily for substantial local symptoms.
The treatment of this problem with anticoagulants occasionally has been complicated by formation of significant calf hematoma5,6 and secondary compartment syndrome. The need for treatment of a true venous thrombosis extending to the popliteal space or proximally is well accepted. Additionally, the threshold pressure for compartment syndrome is controversial, with authors7,8 recommending surgical release for pressures greater than 35 mm Hg or within 30 mm Hg of the diastolic pressure. However, most authors7,8 agree that findings of elevated compartment pressure and correlating symptoms indicate release of the compartments. The most recent report of acute compartment syndrome in the presence of a ruptured Baker's cyst documents this occurring only after the start of anticoagulation therapy9 or in the presence of other significant trauma.