The saphenous opening is a small defect in the fascia lata that covers the anterolateral surface of the thigh.
It's the opening through which the content of the femoral hernia escapes superficially. The saphenous vein also goes through it as it leaves the superficial fascia.
Have a look at this Gray's Anatomy image:
Image is in public domain in USA
Surgeons are well aware of the anatomical landmark of the Saphenous opening when they look for small femoral hernia. It's located 1.5 inferolateral to the pubic tubercle.
probably because the loose adipose tissue will allow it to go upwards...there s no place downwards .... clinically we ve seen a lot of cases like this,....so its difficult to reduce it cause it becomes a full u turn....