Anatomo-radiological study of the popliteal artery during knee flexion.

We studied the morphological modifications of the popliteal artery during knee flexion. An anatomical, radiological study consisted of analysis of lateral arteriographs in different degrees in joint flexion followed by dissection to reveal the anatomical structures involved in the morphological adaptation of the popliteal artery to joint movement. In five non-atheromatous volunteers, 15 MRI angiographic sequences were done at the level of the knee in extension and flexion. The arteriographs and angio MRI showed that as joint flexion increased tortuosities appeared in the supra-articular upper popliteal artery while the middle and lower parts of the popliteal artery kept an even curve retracted from the posterior surface of the joint. Dissection seemed to show that this arterial adaptation occurred between two fixed points, one proximal (the adductor canal) and the other distal (the origin of the anterior tibial artery). Angio MRI seems to be a future route for the assessment of the limb vessels. The contrasting behaviour of the different segments of the popliteal artery allows us to understand better the pathophysiology of trauma and malpositions of the popliteal arterial trunk.