sacral

Sacral is an adjective primarily used in anatomy to denote relation to the sacrum, the large, wedge-shaped bone at the base of the spine formed by the fusion of five sacral vertebrae. It also appears in descriptions of structures in the surrounding region, including portions of the pelvis and the pelvic nerves. The term is derived from Latin and is distinct from the everyday sense of sacred or holy.

In anatomy, the sacrum forms the posterior part of the pelvic girdle and articulates with the ilia at the sacroiliac joints, contributing to the pelvic ring and the posterior boundary of the pelvic cavity. The sacral canal houses the dural sac and sacral nerve roots. The sacral nerves exit through the anterior and posterior sacral foramina and contribute to the sacral plexus, which gives rise to major nerves such as the pudendal nerve and branches to the gluteal, perineal, and lower limb regions.

Clinical notes include anatomical variants such as sacralization, where one of the lowest lumbar vertebrae fuses with the sacrum, and lumbarization, where a sacral segment resembles a lumbar vertebra. Such variations can influence spinal alignment, nerve entrapment, and surgical planning. Imaging modalities like X-ray, CT, and MRI are used to assess sacral anatomy and related pathologies, including fractures, sacroiliitis, and nerve compression.

Beyond medicine, sacral historically relates to sacred or holy things in Latin, but in contemporary usage the term most often refers to the sacrum and its associated structures rather than symbolism or ritual.