Smith Petersen osteotomy (SPOs) yield approximately 10° of lordosis per level, whereas pedicle subtraction osteotomy result in as much as 30° increased lumbar lordosis.

Selective release of the anterior longitudinal ligament (ALL) and placement of lordotic interbody grafts using the minimally invasive lateral retroperitoneal transpsoas approach (XLIF) has been performed as an attempt to increase lumbar lordosis while avoiding the morbidity of osteotomy.