Description
The transverse ridges (transverse lines) of the sacrum are the four horizontal linear elevations that cross the pelvic surface of the bone. Each transverse ridge extends from one anterior sacral foramen to its level corresponding foramen on the opposite side.
The transverse ridges each mark the sites of fusion between the sacral vertebrae, representing the position of the intervertebral discs that were once found in between the five sacral vertebrae in the immature bone.
