In BriefIn this in vitro investigation, we compared the multidirectional flexibility properties of sacral alar iliac fixation with conventional methods of sacral and sacroiliac fixation using nondestructive and destructive investigative methods. The study demonstrated that S1-2 sacral fixation alone significantly increases sacroiliac motion under all loading modalities, while sacral alar iliac fixation reduced motion in axial rotation at the sacroiliac joint and offers potential advantages of a lower instrumentation profile and ease of assembly compared to conventional sacroiliac screw instrumentation.
Keywords: ROM = range of motion; biomechanical properties; iliac screws; sacral alar iliac fixation; sacroiliac junction.