Percutaneous lateral approach to L1 to L4-5. A, Surgeon’s index finger inserted into paraspinal incision site. B, Identification of retroperitoneal space. C, Guidance of the initial dilator into position. D, Retractor inserted into retroperitoneal space, penetrating the psoas major, positioned directly on the lateral intervertebral disc space.(Redrawn from Ozgur BM, Aryan JE, Pimenta L, Taylor WR: Extreme lateral interbody fusion (XLIF): a novel surgical technique for anterior lumbar interbody fusion, Spine J 6:435, 2006.) SEE TECHNIQUE 37.17