I understand that a disc replacement is a better option than a fusion because it saves the motion in the spine. But if I have a disc replacement, do I get my full motion back? I’m not sure how much motion I have now. I’m hardly moving at all because there’s so much pain.

Surgery for degenerative disc disease has traditionally been discectomy (removal of the disc) and spinal fusion. But with the new total disc replacement procedure, more patients are opting for this motion sparing technique. Fusion limits motion at the fused vertebral segments, whereas disc replacement tries to keep as much of the natural motion as possible.

With the removal of the herniated or destroyed disc, pressure is removed from the spinal nerve roots and irritation reduced. The resulting reduction of pain makes it easier to move once again. Studies show that disc replacement patients may lose a little motion at the replacement site but total lumbar spine motion is not always lost because it is made up by the level above. It is somewhat dependent on the level of the disc replacement. So for example, in someone who has an L45 disc replacement, there’s a compensatory increase in motion at the L34 segment. This make-up in motion is not as likely to occur when the replacement is done at the L5S1 level.

In most cases, if the implant is placed with good alignment, then normal biomechanical motion at that level is preserved. This reduces the risk of uneven stresses and evens out the load transmitted to adjacent vertebral segments above. The goal of total disc replacement is to preserve spine motion and normal patterns of movement. The result is prevention of biomechanical strain on the rest of the spine. All indications are that disc replacement to manage degenerative disc disease in the lumbar spine is safe and effective. Long-term results are still as yet undetermined.