Thoraco lumbar injuries can be categorized based on which spinal columns are affected. Injuries involving the middle column and at least one other column are considered unstable. Burst fractures involve failure of the anterior and middle columns and may require early stabilization, especially if they involve over 50% canal compromise, over 20 degrees of kyphosis, or over 45-50% canal compromise. Flexion distraction injuries can be categorized into types A through D depending on whether they involve bone or ligaments at one or two spinal levels.