Popliteal Artery Entrapment Syndrome as a Differential Diagnosis for Knee Pain: A Case Report.

Popliteal artery entrapment syndrome has congenital and functional causes. It mostly affects young people. There are six types of popliteal artery entrapment syndrome. Here, we report a case of type III popliteal artery entrapment syndrome, with an anatomical variation of the gastrocnemius muscle, with an accessory band laterally attached in the femoral condyle compressing the popliteal artery. The patient had characteristic symptoms, with intermittent claudication, paresthesia, absence of blood flow in the posterior tibial and dorsalis pedis arteries during dorsiflexion and plantar flexion of the right foot, and pain in the posterior knee at the physical examination. Imaging supplemented the diagnosis, and the method of choice was magnetic resonance imaging to identify vascular alterations in structures adjacent to the blood vessels in the popliteal fossa. The treatment was surgical for symptom relief and complication prevention. The condition improved with the resection of the accessory band of the gastrocnemius muscle. It is worth noting that the existing literature on the subject is scarce, but the approach adopted here is consistent with other publications. The present report is critical for understanding the popliteal artery entrapment syndrome as a differential diagnosis for knee pain.