Popliteal Artery Pseudoaneurysm Caused by Osteochondroma

A 16-year-old boy developed pulsating pain and dysesthesia in his right knee. Computed tomography showed a large aneurysm in the right upper popliteal artery and a spiked bone tumor arising from the right distal femoral shaft. Pseudoaneurysm due to osteochondroma was suspected, and the patient underwent emergency surgery. A 2-mm pinhole was detected in the arterial wall behind the tumor. After resection of the tumor, the damaged arterial wall was removed, and the defect was repaired using a saphenous vein patch. We suggest that patch repair is preferable to direct closure or end-to-end anastomosis to prevent recurrent pseudoaneurysm at a later time, even if the defect is small.