Sakralkanal

Sakralkanal, known in anatomy as the sacral canal (canalis sacralis in Latin), is a bony passage within the sacrum that continues the vertebral canal as it traverses the fused sacral bones. It extends from the upper sacrum down to the sacral hiatus, where the canal opens at the inferior border of the sacrum. The sacral canal is bounded by the sacral bones and provides a conduit for neural and meningeal structures as they pass toward the pelvic region.

Contents and relations: The sacral canal contains the lower part of the dural sac and the nerve elements of the cauda equina as they descend within the thecal sac toward the sacral foramina. The sacral nerve roots (S1–S5) travel within the canal before exiting through the anterior sacral foramina. The caudal end of the dural sac in adults typically ends near the level of S2, with the remaining nerve roots continuing inside the canal to reach their destinations. The canal is enclosed by the sacral bone and is bordered laterally by the sacral foramina through which the nerve roots exit.

Clinical significance: The sacral canal is relevant in certain medical procedures and imaging. The sacral hiatus at its inferior end is a landmark for caudal epidural anesthesia, a technique commonly used in pediatric and obstetric anesthesia. Pathologies such as sacral canal stenosis, tumors, cysts, or lesions can affect the nerve roots within the canal and may be evaluated using imaging modalities like MRI or CT.

Etymology and usage: The term Sakralkanal is the German designation for this structure; in English, the standard term is sacral canal, with canalis sacralis as the formal anatomical name.