The femoral vein lies medial to the femoral artery in the femoral sheath but lies behind the artery at the apex of the femoral triangle, as do also the profunda artery and vein; all 4 vessels are almost inseparably united in a tough areolar sheath. A stab or bullet wound at the apex of the triangle would penetrate in succession the 4 great vessels of the limb. From before backward they are the femoral artery, the femoral vein, the profunda vein, and the profunda artery.
Surgical Anatomy. Arch Surg. 1997;132(4):449. doi:10.1001/archsurg.1997.01430280123023