Interval Effect of Prone Repositioning for Posterior Spinal Instrumentation after Lateral Interbody Fusion
Introduction: Lateral interbody fusion (LIF) is a minimally-invasive technique used for degenerative disc disease, spondylolisthesis, and deformity where an interbody cage is placed through a lateral incision and retroperitoneal approach with patients positioned lateral decubitus. LIFs are frequently augmented with posterior spinal fusion with instrumentation (PSI) to increase construct rigidity and fusion rate. PSI is traditionally performed with patients positioned prone with the hips and pelvis extended in an attempt to maximize lordosis. In the study herein, the effect of patient repositioning on lumbar lordosis is assessed. Methods: Forty-three patients who underwent LIF with PSI for lumbar stenosis, spondylolisthesis, and/or scoliosis from June 2007 through September 2014 were included. All patients underwent staged surgery with LIF done first followed 1-3 days later by PSI. All patients underwent standing thoracolumbar films prior to LIF, after LIF and then after PSI. Global, lumbosacral and segmental lordosis were measured at each of the three time points. Results: All patients had statistically significant increases in lumbosacral and segmental lordosis after LIF and LIF with PSI. There was no statistically significant change in global, lumbosacral or segmental lordosis between LIF and LIF with PSI. Conclusions: This study revealed that there is no additional lordosis obtained from repositioning a patient prone for PSI after LIF in the lateral decubitus position. These results suggest that it may be feasible to complete the entire LIF with PSI procedure in the lateral position, potentially decreasing operative room time and costs without sacrificing lumbar lordosis.