When pre-planning surgery for a spinal fusion, 3-D spinal models are the most useful tool available to determine the minimum amount of vertebra to join together to accomplish terminating pain and reshaping curvatures of the spine. Lordosis, kyphosis, scoliosis, and spondyolisthesis are all candidates for spinal fusions when other measures such as physical therapy and braces do not work. A spinal fusion is, in terms, is an operation to weld the vertebra together on a specific portion of the spine to correct the shape or prevent bone from rubbing on bone. This procedure limits mobility, so it is of utmost importance to fuse together the least amount of vertebra to accomplish the relief of pain. Use of a 3-D model to make this determination can save time in surgery and lower the cost of performing the operation. More time to recovery can also be avoided.