Where is the popliteal artery located?
The popliteal artery is one of the major arteries in the leg. It is a continuation of the femoral artery and begin at the level of the adductor canal. It then travels obliquely though the popliteal fossa, posterior to the knee joint. It then travels between the gastrocnemius and popliteal muscles before finally bifurcating into the anterior and posterior tibial arteries. Across it journey down the leg it gives off numerous branches that supply several structures.
What is popliteal artery entrapment syndrome (PAES)?
Popliteal artery entrapment syndrome (PAES) is a condition that involves the compression of the popliteal artery or vein as it passes through the popliteal fossa. The vascular structures are obstructed by the gastrocnemius, usually during repetitive knee flexion. The repetitive movement causes an overuse response that leads to a gradual thickening of vessel walls due to excessive pressure from the gastrocnemius (Baltopoulos 2004).
Carneiro described PAES to have six different causes (Carneiro, 2018):
- Type I: An aberrant medial course of the popliteal artery around a normally positioned head of the medial gastrocnemius
- Type II: The medial head of gastrocnemius attaches abnormally and more laterally on the femur causing the popliteal artery to pass medially and inferiorly
- Type III: Abnormal fibrous band or accessory muscle arising from the medial or lateral condyle encircling the popliteal artery
- Type IV: Popliteal artery lying in its primitive deep or axial position within the fossa, becoming compromised by the popliteus muscle or fibrous bands
- Type V: The entrapment of both the popliteal artery and vein due to any of the causes mentioned above
- Type VI: The muscular hypertrophy, resulting in a functional compression of both the popliteal artery and vein
What are the classic features of PAES?
Overall, PAES is not a very common condition that is said to have a prevalence of 0.17% to 3.5% in the general population. 85% of patients affected are male with 60% of those are young athletes in their 20s (Wady, 2018). PAES is commonly described as a deep pain in the calf or feet, intermittent calf cramping or weakness in their legs that develops after intense exercise and dissipates at rest. Repeated ankle dorsiflexion and plantar flexion such as: cycling, running, or marching up and down hills is the most common cause of the symptoms. Furthermore, the person may experience pins and needless or numbness down the back of their calf or they may notice a pale, discoloured foot, and toes. This condition generally occurs on one side but in 30% of cases can occur bilaterally (Davis, 2020).
How do we test for PAES?
PAES is firstly assessed in clinic with a thorough history and physical examination. If this leads to suspicion of PAES, the person is referred to get a Diagnostic Doppler Ultrasound to assess the integrity of the vessels.
To assess for PAES in clinic is to examine the distal pulses of the lower extremities. This is measured by palpating the pulse at rest and comparing to the other side. The person is then asked to complete active plantarflexion and/or passive dorsiflexion of the ankle with the knee remaining in extension. While this is occurring, the distal pulse will be palpated and then compared to at rest and the other side.
How do we treat PAES?
Depending of the presentation of type of PAES the treatment is individualised for the person and the goals they want to achieve. Generally, the treatment involves a surgical release or bypass of the popliteal artery, a fasciotomy, myotomy to re-establish normal anatomy. From there a rehabilitation program is undertaken to restore range of movement and strength. Please seek medical advice from your Chiropractor, Physiotherapist or Sports Doctor if symptoms do not resolve or become severe. Remember, the quicker you take care of your pain, the quicker you will be back to doing what you love.
1. Baltopoulos, P., Filippou, D. K., & Sigala, F. (2004). Popliteal artery entrapment syndrome: anatomic or functional syndrome?. Clinical Journal of Sport Medicine, 14(1), 8-12.
2. Carneiro Júnior FCF, Carrijo ENDA, Araújo ST, Nakano LCU, de Amorim JE, Cacione DG. Popliteal Artery Entrapment Syndrome: A Case Report and Review of the Literature. Am J Case Rep. 2018 Jan 09;19:29-34
3. Davis, D. D., & Shaw, P. M. (2020). Popliteal artery entrapment syndrome. StatPearls.
4. Wady, H., Badar, Z., Farooq, Z., Shaw, P., & Kobayashi, K. (2018). Avoiding the trap of misdiagnosis: valuable teaching points derived from a case of longstanding popliteal artery entrapment syndrome. Case reports in medicine, 2018.