Digit ratio and the femoral circumflex artery perforator: A sex-dependent association between the vascular system of the thigh and prenatal sex hormones?

[BACKGROUND] The anterolateral thigh flap (ALTF) is a type of free flap which is commonly used in reconstructive surgery procedures and is based on the perforator from femoral circumflex artery. Some authors found that the location of the perforator differs between sexes.

[OBJECTIVE] To verify the influence of prenatal sex hormones (as measured by 2D:4D) on the morphology of the perforator of the descending branch of the femoral circumflex artery.

[METHODS] 88 participants (43 women) of a mean age of 28.5 years (SD 8.1 years) had the following measurements performed: height and weight; right and left-hand 2nd and 4th fingers' lengths; and distance from anterior superior iliac spine to the perforator from descending branch of lateral femoral circumflex artery related to the thigh length (right and left) (AP ratio).

[RESULTS] Right 2D:4D and Dr-l (right minus left 2D:4D) were dimorphic, similarly to AP ratio (right and left), which in women was significantly higher than in men. A significant correlation was found between right and left 2D:4D and location of the perforator of the left thigh in men. The higher right and left 2D:4D (more feminine) the higher the left AP ratio (more feminine).

[CONCLUSION] Our findings suggest that the location of perforator of femoral circumflex artery may be influenced by prenatal sex steroids such that low prenatal testosterone and high prenatal oestrogen are correlated to high AP (lower branching of the artery).