 A high-speed Cornerstone bur was used to decorticate the bodies of C5-C6, C4-C5 and C3-C4 to create a posterior shelf to prevent backwards graft migration. 
A high - speed Cornerstone bur was used to decorticate the bodies of C5 - C6 , C4 - C5 and C3 - C4 to create a posterior shelf to prevent backwards graft migration .