Сдается мне, что это все артерии, которые находятся ниже места деления подколенной на переднюю и заднюю большеберцовые и малоберцовую артерии (того места, которое американцы называют трифуркацией). Можно, наверное, перевести как "конечные ветви подколенной артерии". Или перечислить все три. А вообще, термин скорее клинический, чем анатомический.

Below the knee, the popliteal artery trifurcates to form the anterior and posterior tibial arteries and the peroneal artery.

A Practical Approach to Endovascular Therapy for Infrapopliteal Disease
...infrapopliteal arteries (anterior tibial, peroneal, and posterior tibial) is ...
www.invasivecardiology.com/article/3606

http://www.emedicine.com/med/topic2719.htm
This article is a review of chronic infrainguinal atherosclerotic arterial occlusive disease caused by atherosclerosis involving the femoral, popliteal, and/or infrapopliteal arteries.

Из нашего перевода Харрисона:
The primary sites of involvement are the abdominal aorta and iliac arteries (30% of symptomatic patients), the femoral and popliteal arteries (80 to 90% of patients), and the more distal vessels, including the tibial and peroneal arteries (40 to 50% of patients).
У 30% больных поражен аортоподвздошный сегмент, у 80—90% — бедренно-подколенный, у 40—50% — ¶мелкие ¶дистальные ¶артерии, в частности большеберцовые и малоберцовые.

www.evtoday.com/PDFarticles/0306/EVT0306_F5_Lin.pdf...
When Is Surgery Still the Best Option?
...TransAtlantic inter-Society Consensus
(TASC) task force, which published classification guidelines
for iliac, femoropopliteal, and infrapopliteal atherosclerotic
disease.
Based on these guidelines, femoropopliteal lesions are
divided into four types: A, B, C, and D. Type A lesions are
single focal lesions less than 3 cm in length not involving
the origins of the superficial femoral artery (SFA) or the
distal popliteal artery; type B lesions are single lesions 3 cm
to 5 cm in length not involving the distal popliteal artery
or multiple or heavily calcified lesions less than 3 cm in
length; type C lesions are single and more than 5 cm in
length, or multiple lesions between 3 cm and 5 cm in
length with or without calcification; and type D lesions are
those with complete occlusion of the common femoral
artery (CFA), SFA, or popliteal artery.
Similarly, infrapopliteal arterial diseases are classified into
four types based on the TASC guidelines. Type A includes
single lesions less than 1 cm in length not involving the trifurcation;
type B describes multiple lesions less than 1 cm
in length or single lesions shorter than 1 cm involving the
trifurcation; type C lesions are those that extensively
involve the trifurcation (those that are 1-cm to 4-cm
stenotic, or 1-cm to 2-cm occlusive lesions); and type D
lesions are occlusions longer than 2 cm or diffuse disease.