Figure 43-13 Neuraxial anatomy of the Taylor approach to spinal anesthesia. This is really a paramedian approach at the L5-S1 vertebral level. A skin mark is made 1 cm caudad and 1 cm medial to one of the posterior superior iliac spines. Through this skin mark, the needle is inserted in a cephalad and medial direction. The needle is walked off the sacrum and into the largest interspinous space, the L5-S1 intervertebral space. The posterior superior iliac spines are located immediately anterior to the often present "skin dimples" found overlying the superior aspect of the sacrum. (Courtesy of the Mayo Foundation, Rochester, MN.)