GIANT BAKER'S CYST AND PSEUDOTHROMBOPHLEBITIS IN PATIENTS WITH RHEUMATIC DISEASES: A NEW INSIGHT INTO OLD COMPLICATIONS

Background: The knee joint is the most common site for cyst formation. Popliteal cyst may become large and its compressive effects produce complications particularly in subacute and chronic rheumatic diseases. Methods: We evaluated predisposing factors, underlying diseases, complications, course and management of giant Baker's cysts in our patients with rheumatic diseases. Patients with popliteal cysts that extended down lower than inferior level of the popliteal fossa, confirmed by imaging techniques were included in this retrospective study. Results: A total of 40 patients had giant Baker's cysts during last 20 years. Rheumatoid arthritis was the most prevalent disease in 21 patients (52.5%). Our cases included a large series of patients with seronegative spondyloarthropathies complicated with giant Baker's cyst in 10 patients (25%). Localized bulging, pain and tenderness of the calf region were observed in 15 patients (37.5%). A total of 25 patients had symptoms and signs similar to thrombophlebitis (62.5%). Rupture of Baker's cyst was detected in 10 patients (25%). A patient had giant Baker's cyst concurrent with thrombophlebitis. Management was mostly conservative including rest and intra-articular depoglucocorticoid injection with satisfactory results. Conclusions: In this study, rheumatoid arthritis was the most prevalent underlying disease and the pseudothrombophlebitis syndrome was the most prevalent presenting feature of patients with giant Baker's cysts.