EN
The dorsal wall of the sacrum presents various anatomical variations, while the dorsal bony wall of the sacral canal suffers more. We report a case of a sacrum with a series of variants in the midline due to abnormal ossification and a bizarre aperture on the sagittal plane between the 1st and the 2nd sacral spinous processes. A failure of the ossification patter during embryological life, or an ossification of the supraspinous ligament may result in such an aperture. Sacrum variety is of great importance for the daily proper medical practice. (Folia Morphol 2020; 79, 1: 179–181)