Surface marking of the deep inguinal ring

The surface marking of the deep inguinal ring (DIR) is commonly described as being located at either the middle of the inguinal ligament (MIL) or at the mid-inguinal point (MIP); there seems to be no consensus in previous studies in patients with inguinal hernias. The present study was carried out to determine a more accurate location of the DIR in individuals without inguinal hernias. Fifty-two cadavers without inguinal hernias were dissected and the positions of the DIR, MIL, MIP and femoral artery (FA) were determined. The mean distance from the anterior superior iliac spine (ASIS) to the DIR was 62 mm, where as the mean distance from the ASIS to the MIL, MIP, and FA were 55, 66, and 65 mm, respectively. The study showed that in individuals without inguinal hernias the DIR did not correspond to the MIL or MIP, but rather to an area between these two landmarks. The surface marking of the DIR may be best described as at the mid-inguinal region.