the role of artificial or total disc replacement in the treatment of spinal disorders remains ill-defined and unclear. evaluation of any new technique is difficult or impossible because physician experience may be minimal or lacking. patient expectations may be distorted. it has been difficult to establish clear cut indications for artificial disc replacement. it may not be a replacement procedure or alternative to fusion, since recent studies have shown that 100% of fusion patients had one or more contraindications to disc replacement. the role of disc replacement must come from new indications not defined in today's 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. tens units work by blocking neurotransmission as described by the pain theory of melzack and wall. success rates for implanted neurostimulation has been reported to be 25% to 55%. success is defined as a relative decrease in pain. chiropractic limited case series have shown improvement for patients with failed back surgery who were managed with chiropractic care. avoiding post-laminectomy/laminotomy syndrome smaller procedures that do not remove bone (such as endoscopic transforaminal lumbar discectomy and reconfiguration) do not cause post laminectomy/laminotomy syndrome. prognosis under rules promulgated by titles ii and xvi of the united states social security act, chronic radiculopathy, arachnoiditis and spinal stenosis are recognized as disabling conditions under listing 1.04 a (radiculopathy), 1.04 b (arachnoiditis) and 1.04 c (spinal stenosis). return to work ct scan showing post operative scarring and arachnoiditis. in a groundbreaking canadian study, waddell et al. reported on the value of repeat surgery and the return to work in worker's compensation cases. they concluded that workers who undergo spinal surgery take longer to return to their jobs. once two spinal surgeries are performed, few if any ever return to gainful employment of any kind. after two spinal surgeries, most people in the worker's comp system will not be made better by more surgery. most will be worse after a third surgery. episodes of back pain associated with on the job injuries in the worker's compensation setting are usually of short duration. about 10% of such episodes will not be simple, and will degenerate into chronic and disabling back pain conditions, even if surgery is not performed. it has been hypothesized that job dissatisfaction and individual perception of physical demands are associated with an increased time of recovery or an increased risk of no recovery at all. individual psychological and social work factors, as well as worker-employer relations are also likely to be associated with time and rates of recovery. a finnish study of return to work in patients with spinal stenosis treated by surgery found that: (1) none of the patients who had retired before the operation returned to work afterward. (2) the variables that predicted postoperative ability to work for women were: being fit to work at the time of operation, age < 50 years at the time of operation, and duration of lumbar spinal stenosis symptoms < 2 years. (3) for men, these variables were: being fit to work at the time of operation, age < 50 years at the time of operation, no prior surgery, and the extent of the surgical procedure equal to or less than one laminectomy. women's and men's working capacity do not differ after lumbar spinal stenosis operation. if the aim is to maximize working capacity, then, when a lumbar spinal stenosis operation is indicated, it should be performed without delay. in lumbar spinal stenosis patients who are > 50 years old and on sick leave, it is unrealistic to expect that they will return to work. therefore, after such an extensive surgical procedure, re-education of patients for lighter jobs could improve the chances of these patients returning to work. in a related finnish study, a total of 439 patients operated on for lumbar spinal stenosis during the period 1974–1987 was re-examined and evaluated for working and functional capacity approximately 4 years after the decompressive surgery. the ability to work before or after the operation and a history of no prior back surgery were variables predictive of a good outcome. before the operation 86 patients were working, 223 patients were on sick leave, and 130 patients were retired. after the operation 52 of the employed patients and 70 of the unemployed patients returned to work. none of the retired patients returned to work. ability to work preoperatively, age under 50 years at the time of operation and the absence of prior back surgery predicted a postoperative ability to work. a report from belgium noted that patients reportedly return to work an average of 12 to 16 weeks after surgery for lumbar disc herniation. however, there are studies that lend credence to the value of an earlier stimulation for return to work and performance of normal activities after a limited discectomy. at follow-up assessment, it was found that no patient had changed employment because of back or leg pain. the sooner the recommendation is made to return to work and perform normal activities, the more likely the patient is to comply. patients with ongoing disabling back conditions have a low priority for return to work. the probability of return to work decreases as time off work increases. this is especially true in belgium, where 20% of individuals did not resume work activities after surgery for a disc herniation of the lumbar spine. in belgium, the medical advisers of sickness funds have an important role legally in the assessment of working capacity and medical rehabilitation measures for employees whose fitness for work is jeopardized or diminished for health reasons. the measures are laid down in the sickness and invalidity legislation. they are in accordance with the principle of preventing long-term disability. it is apparent from the authors' experience that these measures are not adapted consistently in medical practice. most of the medical advisers are focusing purely on evaluation of corporal damage, leaving little or no time for rehabilitation efforts. in many other countries, the evaluation of work capacity is done by social security doctors with a comparable task. in a comprehensive set of studies carried out by the university of washington school of medicine, it was determined that the outcome of lumbar fusion performed on injured workers was worse than reported in most published case series. they found 68% of lumbar fusion patients still unable to return to work two years after surgery. this was in stark contrast to reports of 68% post-op satisfaction in many series. in a follow-up study it was found that the use of intervertebral fusion devices rose rapidly after their introduction in 1996. this increase in metal usage was associated with a greater risk of complication without improving disability or re-operation rates. research the identification of tumor necrosis factor-alpha (tnf) as a central cause of inflammatory spinal pain now suggests the possibility of an entirely new approach to selected patients with fbss. specific and potent inhibitors of tnf became available in the u.s. in 1998, and were demonstrated to be potentially effective for treating sciatica in experimental models beginning in 2001. targeted anatomic administration of one of these anti-tnf agents, etanercept, a patented treatment method, has been suggested in published pilot studies to be effective for treating selected patients with chronic disc-related pain and fbss. the scientific basis for pain relief in these patients is supported by the many current review articles. in the future new imaging methods may allow non-invasive identification of sites of neuronal inflammation, thereby enabling more accurate localization of the "pain generators" responsible for symptom production. these treatments are still experimental. if chronic pain in fbss has a chemical component producing inflammatory pain, then prior to additional surgery it may make sense to use an anti-inflammatory approach. often this is first attempted with non-steroidal anti-inflammatory medications, but the long-term use of non-steroidal anti-inflammatory drugs (nsaids) for patients with persistent back pain is complicated by their possible cardiovascular and gastrointestinal toxicity; and nsaids have limited value to intervene in tnf-mediated processes. an alternative often employed is the injection of cortisone into the spine adjacent to the suspected pain generator, a technique known as "epidural steroid injection". although this technique began more than a decade ago for fbss, the efficacy of epidural steroid injections is now generally thought to be limited to short term pain relief in selected patients only. in addition, epidural steroid injections, in certain settings, may result in serious complications. fortunately there are now emerging new methods that directly target tnf. these tnf-targeted methods represent a highly promising new approach for patients with chronic severe spinal pain, such as those with fbss. ancillary approaches, such as rehabilitation, physical therapy, anti-depressants, and, in particular, graduated exercise programs, may all be useful adjuncts to anti-inflammatory approaches. in addition, more invasive modalities, such as spinal cord stimulation, may offer relief for certain patients with fbss, but these modalities, although often referred to as "minimally invasive", require additional surgery, and have complications of their own. worldwide perspective ct scan showing two views of l4-5 disc herniation a report from spain noted that the investigation and development of new techniques for instrumented surgery of the spine is not free from conflicts of interest. the influence of financial forces in the development of new technologies and its immediate application to spine surgery, shows the relationship between the published results and the industry support. authors who have developed and defended fusion techniques have also published new articles praising new spinal technologies. the author calls spinal surgery the "american stock and exchange" and "the bubble of spine surgery". the scientific literature doesn't show clear evidence in the cost-benefit studies of most instrumented surgical interventions of the spine compared with the conservative treatments. it has not been yet demonstrated that fusion surgery and disc replacement are better options than the conservative treatment. it's necessary to point out that at present "there are relationships between the industry and back pain, and there is also an industry of the back pain". nonetheless, the "market of the spine surgery" is growing because patients are demanding solutions for their back problems. the tide of scientific evidence seems to go against the spinal fusions in the degenerative disc disease, discogenic pain and in specific back pain. after decades of advances in this field, the results of spinal fusions are mediocre. new epidemiological studies show that "spinal fusion must be accepted as a non proved or experimental method for the treatment of back pain". the surgical literature on spinal fusion published in the last 20 years establishes that instrumentation seems to slightly increase the fusion rate and that instrumentation doesn't improve the clinical results in general. we still are in need of randomized studies to compare the surgical results with the natural history of the disease, the placebo effect, or conservative treatment. the european guidelines for lumbar chronic pain management show "strong evidence" indicating that complex and demanding spine surgery where different instrumentation is used, is not more effective than