The role of disc replacement must come from new indications not defined in todays literature or a relaxation of current contraindications.A study by Regan     found the result of replacement was the same at L4-5 and L5-S1 with the CHARITE disc. However, the ProDisc II had more favorable results at L4-5 compared with L5-S1.A younger age was predictive of a better outcome in several studies. In others it has been found to be a negative predictor or of no predictive value. Older patients may have more complications.Prior spinal surgery has mixed effects on disc replacement. It has been reported to be negative in several studies. It has been reported to have  no effect in other studies. Many studies are simply inconclusive. Existing evidence does not allow drawing definite conclusions about the status of disc replacement at present. Electrical stimulation
Many failed back patients are significantly impaired by chronic pain in the back and legs. Many of these will be treated with some form of electrical stimulation. This can be either a transcutaneous electrical nerve stimulation device placed on the skin over the back or a nerve stimulator implanted into the back  with electrical probes which directly touch the spinal cord. Also, some chronic pain patients utilize fentanyl or narcotic patches. These patients are generally severely impaired and it is unrealistic to conclude that application of neurostimulation will reduce that impairment. For example, it is doubtful that neurostimulation will improve the patient enough to return to competitive employment. Neurostimulation is palliative.
Responses to this treatment can vary and are impacted if the patient is diagnosed with any type of cancer. Patients who respond positively show improvement in the clarity of their vision and their visual field. Plasmapheresis
Plasmapheresis involves separating blood into two parts - blood cells and plasma. The blood plasma components, such as the antibodies, are treated outside of the body. After removal of the disease-associated antibodies, the blood cells and plasma are transfused back into the body. Response to this treatment depends on how much retinal damage has been done. Patients who respond positively show significant visual gains. Corticosteroids
Corticosteroids are administered through IV or orally. They cause lymphocytopenia, a condition where white blood cell levels are abnormally low. Corticosteroids cause white blood cell death, lowering their numbers throughout the body. They also cause white blood cells to recirculate away from the area of damage (the retina). This minimizes damage caused by the antibodies produced by the white blood cells. Often, this is treatment is combined with plasmapheresis. Instead of treating the plasma and blood cells, they are replaced with a healthy donor mixture. Patients who respond positively show improved visual fields and an almost complete disappearance of anti-retinal antibodies. == References ==