https://www.selleckchem.com/products/tlr2-in-c29.html Visual assessment of the vertebral bone structure on micro-CT was performed. FINDINGS There was no change in motion segment stiffness in flexion/extension nor in axial rotation. There was a reduction in stiffness in lateral bending with 30% reduction bending away from the staple and 12% reduction bending towards the staple. Micro-CT showed physeal damage in all the specimens. INTERPRETATION Intervertebral stapling using SMA staples cause a reduction in spine stiffness in lateral bending. They also cause damage to the endplate epiphyses. BACKGROUND Screw loosening is a major complication following spondylodesis. While several modifications increase screw stability, some, such as screw augmentation, are associated with potential complications; new techniques are needed to minimize the risk of screw loosening without increasing complication rates. METHODS 13 fresh-frozen human lumbar vertebral bodies (L1 to L5) were dissected. In group 1 (n = 7), pedicle screws were implanted conventionally, while in group 2 (n = 6), the screws were positioned divergent in the sagittal pathway. Screw stability was tested under cyclic axial load; one testing-cycle included 1000 repetitions. The first cycle started with a load of 100 N while the load was increased by +20 N in each following cycle until failure. Failure was defined by either a >5 mm movement of the screw heads or triggering of the switch-off threshold. FINDINGS Average number of cycles until failure was increased in group 2 compared with group 1 (12,046 vs 9761 cycles), as was the average load to failure (Fmax 313 N vs 260 N). Overall, in group 2, the number of cycles until screw loosening or failure increased by 23% (p = 0.28), while the required force increased by 20% (p = 0.3). Statistically significant correlation between BMD and increased number of cycles completed as well as with increased load (p less then 0.01) could be observed. INTERPRETATION The results demo