Biomechanical Comparison of Anterior and Direct Lateral Interbody Fusion with Supplemental Instrumentation

INTRODUCTION: Direct lateral interbody fusion (DLIF) is less invasive than traditional methods, such as anterior lumbar interbody fusion (ALIF). While the direct lateral approach is safer for a variety of clinical reasons, immobilization of motion segments is crucial for complete bony union, regardless of approach. Therefore, biomechanical assessment is necessary to determine if the DLIF approach is a viable alternative to standard procedures, such as ALIF. The goal of this cadaveric biomechanical study was to compare the immediate postoperative stability of DLIF and ALIF. Further, any additional stiffness imparted by supplemental instrumentation was quantified. We hypothesized that the two approaches would be biomechanically equivalent, and that supplemental instrumentation would be comparably beneficial for both techniques.