First sacral nerve and anterior longitudinal ligament anatomy: clinical applications during sacrocolpopexy

Awareness of the first sacral nerve position, approximately 2.5 cm below the midpoint of the sacral promontory and 2 cm to the right of midline, should help anticipate and avoid somatic nerve injury during sacrocolpopexy. Knowledge of the approximate 2-mm thickness of the anterior longitudinal ligament should help reduce risk of discitis and osteomyelitis, especially when graft is affixed above the level of the sacral promontory.