Abstract
A 70-year-old man presented with a Baker cyst in his left knee. Two months previously he had undergone a femoro-popliteal artery bypass graft above the knee under a diagnosis of the arteriosclerosis obliterans. Baker cysts are often associated with intra-articular disorders of the knee joint, especially osteoarthritis, rheumatoid arthritis and meniscal tears. To the best of our knowledge, there has been no report about Baker cyst occurring after a femoro-popliteal bypass without an intra-articular disorder of the knee joint. We describe this rare case and its clinical course from onset to operation.