Previous studies of cervical fusion have noted the appearance of new degeneration at levels adjacent to fused segments. The cause of this degeneration has not been accurately determined. The objective of this project is to determine the forces in normal and fused spines in vivo and compare the results to see if the forces in the fused spine are increased enough to cause degeneration in adjacent levels.

A normal and a fused patient (one level fused in C5-C6) have been chosen to perform a full flexion and extension motion experiments. Kinematic functions were obtained from the images. Data was input into the mathematical model and the kinetic results have been decided.

The result can help us understand in vivo kinematical and kinetic characteristics of cervical spine fusion and develop further studies in 3D models. The calculated forces will be compared to previously reported data to determine if the expected increased forces in the fused spinal are great enough to cause degeneration of adjacent levels. A better understanding will help in better treatment of cervical spine disorders.