The profunda femoris artery may arise from the lateral aspect of the femoral artery at the level of the inguinal ligament in which case two main arteries enter the limb. Or, it may arise four inches below the inguinal ligament, in which case only one artery traverses the femoral triangle (usually 75% of the cases). It is only slightly smaller than the continuation of the femoral artery itself and is therefore no mean vessel.
Source: Boileau Grant JC. A Method of Anatomy: Descriptive and Deductive. 5th ed. Baltimore, Md: Williams & Wilkins Co; 1952:388.
March 2003. Arch Surg. 2003;138(3):343. doi:10.1001/archsurg.138.3.343