Coccygeal

Coccygeal refers to anything related to the coccyx, the small bone at the lower end of the vertebral column commonly known as the tailbone. In humans the coccyx typically comprises three to five rudimentary vertebrae (Co1–Co4 or Co5) that are usually fused in adulthood.

Anatomy and location

The coccyx sits below the sacrum and articulates with it at the sacrococcygeal joint, which is often a slightly movable link that can range from cartilaginous to fibrous in adults. The coccyx serves as an attachment point for several muscles, ligaments, and connective tissues of the pelvic floor, including portions of the levator ani and coccygeus muscles, as well as various ligaments. It contributes to the structural support of the pelvic region and provides a site for weight transfer and muscle leverage during sitting and certain movements.

Variation and development

The exact number of coccygeal vertebrae varies among individuals, and elements commonly fuse with age. The coccyx exhibits considerable anatomical variation in shape and angle, and congenital anomalies such as coccygeal agenesis or hypoplasia can occur, though these are uncommon. Such variations can influence susceptibility to certain conditions affecting the posterior pelvis.

Clinical relevance

Coccydynia, or pain in the coccygeal region, is the most common coccygeal-related condition. It often follows trauma, prolonged sitting, or childbirth and may be managed with conservative measures such as cushions, activity modification, anti-inflammatory medications, and physical therapy. Persistent cases may require intervention, including injections or, rarely, surgical removal of part or all of the coccyx (coccygectomy) after thorough evaluation.

Etymology

The term coccygeal derives from Latin coccyx, itself from Greek kolkyx or kokkyx, meaning “cuckoo,” a reference to the bone’s hooked, curved shape.