Adjacent segment motion after a simulated lumbar fusion in different sagittal alignments: a biomechanical analysis.

Abstract

Hypolordotic alignment at L4-L5 caused the greatest amount of flexion-extension motion at L3-L4, and the differences were statistically significant in comparison with intact specimen, in situ fixation, and hyperlordotic fixation. Hyperlordotic alignment at L4-L5 caused the greatest amount of flexion-extension motion at L5-S1, and the difference was statistically significant in comparison with intact specimen but not in situ fixation or hypolordotic fixation.