The Vesalaev bone, or Vesalius bone, is a sacrotuberous bone (Latin os vesalianum), one of the long bones of the human skeleton. It is located in the pelvic cavity and is almost completely covered by muscles (except for the medial surface, which is directly adjacent to the pubic symphysis). The sacropelvic ligament is attached to the upper third of the bone, and the sacropelvic ligament is attached to the lower third. The bones of the anterior body are covered with fascia and ligaments that form a complex. The name “Vesalius bone” was given in honor of the Dutch anatomist Vesalai, who studied its structure in the 16th century.