Biomechanical analysis of structural stability of internal fixation in fractures of the thoracolumbar spine.

Three different methods of internal fixation for the flexion-rotation thoracolumbar spinal fractures were tested biomechanically in a cadaver model for strength, mode of failure and ease of application. The compression rod system was clearly superior in strength and rotational stability to the spring device, but it was more difficult to apply than springs. The distraction rod system exhibited an intermediate level of strength with adequate rotational stability. Technically, the method is exacting and requires a clear understanding of its principle of 3 point fixation.