Popliteal venous thrombosis in juvenile arthritis with Baker cysts: report of 3 cases

Large Baker cysts-particularly following rupture-may lead to calf swelling and pseudothrombophlebitis that has been described in many adult and juvenile patients [1,2]. Pseudothrombophlebitis implies that symptoms of a venous thrombosis such as calf swelling are present, but not caused by thrombophlebitis. True popliteal venous thrombosis has only rarely been reported [3]. We recently saw 3 patients with different forms of juvenile arthritis and Baker cysts without a prior personal or family history of thrombotic events who developed popliteal venous thrombosis and upon work-up following the thrombosis had risk factors for thrombophilia.Patient 1 was a 13-year old boy with a 9-year history of systemic juvenile idiopathic arthritis who developed left knee arthritis after a period of 18 months of disease remission off any medication. Several days later he also complained of painful calf swelling. On ultrasound examination a Baker cyst (52 × 28 × 24 mm) and 2 smaller cysts were found as well as incomplete popliteal venous thrombosis. During treatment with enoxaparin the thrombus dissolved within 2 weeks, and enoxaparin was stopped after 5 months. The knee arthritis improved with naproxen and methotrexate and after intraarticular injection of triamcinolone hexacetonide. At last follow-up 18 months later, the patient felt entirely well without effusion but a very small cyst remained.Patient 2 was a 9-year-old girl with juvenile idiopathic oligoarthritis and 5 months of right knee arthritis treated with naproxen who newly complained of painful calf swelling. Sonography showed a 74 × 34 × 13 mm large Baker cyst as well as an incomplete thrombosis of the popliteal vein. With enoxaparin normal venous flow was reestablished within 3 months and enoxaparin was then stopped. The arthritis improved rapidly following intraarticular injection of triamcinolone hexacetonide and continued naproxen. Nine months later the girl had no complaints, and sonography found a smaller Baker cyst