=====Smith Petersen osteotomy=====
[[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.