Classic history and presentation: This often presents as claudication in young, active males during intense physical activities that involve dorsiflexion and plantarflexion of the ankles. The typical manifestation is pain, cramping, or paresthesia in the deep calf after intense exercise. Additional symptomatology includes swelling, blanching, pallor, and coldness in the lower legs and feet, especially immediately after exercise. The manifestations should improve with rest. Conversely, a patient could be asymptomatic.
- Age – Predominantly young men (20-40 years), but typically younger than 30 years.
- Incidence – Ranges from 0.6%-3.5%
- Sex / gender – Males are substantially more affected than females (15:1 male-to-female ratio)
Pathophysiology: The long-term compression of the popliteal artery leads to the thickening of the artery and complications such as ischemia, stenosis, thromboembolization, occlusion, and aneurysm formation.
Grade / classification system: Two main categories – anatomic (I-VI) and functional (compression of the popliteal neurovascular structures secondary to muscle hypertrophy of the gastrocnemius, soleus, and/or plantaris)
- I – The popliteal artery is displaced medially around the medial head of the gastrocnemius.
- II – Medial head of the gastrocnemius is attached laterally.
- III – Accessory slip of the gastrocnemius passing below popliteus muscle or fibrous bands arising from the medial head of the popliteus.
- IV – Popliteal artery passing below the popliteus muscle or fibrous bands arising from the popliteus.
- V – Primarily popliteal venous entrapment
- VI – Other variants
- F – Functional entrapment