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.
In addition, spinal fusion itself, particularly if more than one spinal level is operated on, may result in "adjacent segment degeneration". This is thought to occur because the fused segments may result in increased torsional and stress forces being transmitted to the intervertebral discs located above and below the fused vertebrae. This pathology is one reason behind the development of artificial discs as a possible alternative to fusion surgery. But fusion surgeons argue that spinal fusion is more time-tested, and artificial discs contain metal hardware that is unlikely to last as long as biological material without shattering and leaving metal fragments in the spinal canal. These represent different schools of thought. (See discussion on disc replacement infra.) Another highly relevant consideration is the increasing recognition of the importance of "chemical radiculitis" in the generation of back pain. A primary focus of surgery is to remove "pressure" or reduce mechanical compression on a neural element: either the spinal cord, or a nerve root. But it is increasingly recognized that back pain, rather than being solely due to compression, may instead entirely be due to chemical inflammation of the nerve root. It has been known for several decades that disc herniations result in a massive inflammation of the associated nerve root. In the past five years increasing evidence has pointed to a specific inflammatory mediator of this pain.