Does Lateral Lumbar Interbody Fusion Decrease the Grading of Lenke-Silva Classification and Determine the Optimal Fusion Level in Severe Adult Degenerative Scoliosis?

Abstract

To testify whether lateral lumbar interbody fusion (LLIF) decreases the Lenke-Silva classification grading and determines the optimal fusion level in adult degenerative scoliosis (ADS) of global imbalance. Thirty-seven patients with ADS of level V and VI based on Lenke-Silva classification were included. After the first-stage LLIF, patients received reassessment and were divided into group A (the Lenke-Silva classification grading changed) and group B (the grading was unchanged). Posterior fixation was performed according to the reassessment. The demographic, operative, radiographic, and clinical data were compared between the 2 groups. Twenty-five patients of level V and 12 patients of level VI were included, with a mean follow-up of 29.6 months. After first-stage LLIF, the Lenke-Silva classification grading changed in 22 patients (group A), with the remaining 15 patients unchanged (group B). There were significant differences in preoperative Lenke-Silva classification grading, use of anterior column realignment and hyperlordotic cage and high-grade cage subsidence between the 2 groups. The posterior fusion levels in the second surgery were less and the rate of fusion to thoracic spine region was lower in group A. The visual analog scale and Oswestry Disability Index were significantly improved and restorations of coronal and sagittal balance were found at the latest follow-up in both groups. LLIF decreased the Lenke-Silva classification grading and determined the optimal fusion level in patients with severe ADS. Change of Lenke-Silva classification may be associated with preoperative Lenke-Silva classification grading, use of anterior column realignment, and hyperlordotic cage.