Apex Of The Coccyx

Description

Coccyx apex occupies the inferior midline of the vertebral column, and in posterior aspect the terminal coccygeal segment (often Co4) narrows to a blunt tip just inferior to the third and fourth sacral segments. Superior to the apex, the dorsal surface of the coccyx shows the fused remnants of coccygeal vertebrae with a shallow median ridge, and the paired coccygeal cornua project cranially toward the sacral cornua at the sacrococcygeal joint. Lateral margins taper quickly, with small transverse processes when present, and the posterior surface provides attachment for fibers of gluteus maximus and the anococcygeal ligament at the midline. Posterior bony landmarks at the coccyx matter in coccydynia after a fall, postpartum coccygeal subluxation, and in operative planning for coccygectomy when conservative management fails. Palpation and surface localization depend on recognizing how the apex sits inferior to the sacrococcygeal junction and how a retroverted coccyx can change the contact point during sitting. Small details help. The fixed rear perspective supports correlation with posterior pelvic radiographs and with interventional pain procedures that use a dorsal approach to the sacrococcygeal or intercoccygeal joint as a route toward the ganglion impar on the anterior surface. Use this illustration in pelvic anatomy teaching, orthopedic and pain medicine slide decks on coccydynia, or surgical atlases that need a posterior osseous reference for midline incisions and coccygeal resection margins. It also fits patient education materials explaining tailbone trauma and why focal tenderness localizes to the coccyx tip. Anatomical accuracy verified by SciePro's Medical Advisory Board.