Abstract:
The lordosis of the lumbar spine and body weight result in significant shear forces through the lumbosacral elise spaces. These forces result in translational motion across the disc space, which is resisted but not completely abolished by pedicle screw stabilization. It is postulated that this motion may be a factor in the development of nonunion of lumbar interbody fusions. An in vitro study of the micromotion of porcine specimens with serrated or smooth interbody spacers and subjected to shear forces under compressive preload was conducted to determinewhether the surface serrations on vertebral interbody implants significantly resist shear forces and resulting sagittal translation.
