Cause Failed back syndrome

spinal surgeons operating on back.

patients have undergone 1 or more operations on lumbar spine, , continue experience , report pain afterward can divided 2 groups. first group in whom surgery never indicated, or surgery performed never achieve desired result; , in whom surgery indicated, technically did not achieve intended result. has been observed patients have predominant painful presentation in radicular pattern have better result have predominant complaints of pain.

the second group includes patients had incomplete or inadequate operations. lumbar spinal stenosis may overlooked, when associated disc protrusion or herniation. removal of disc, while not addressing underlying presence of stenosis, can lead disappointing results. operating on wrong level occurs, failure recognize extruded or sequestered disc fragment. inadequate or inappropriate surgical exposure can lead other problems in not getting underlying pathology. hakelius reported 3% incidence of serious nerve root damage.

in 1992, turner et al. published survey of 74 journal articles reported results after decompression spinal stenosis. excellent results on average reported 64% of patients. there was, however, wide variation in outcomes reported. there better result in patients had degenerative spondylolisthesis. designed study mardjekto et al. found concomitant spinal arthrodesis (fusion) had greater success rate. herron , trippi evaluated 24 patients, degenerative spondylolisthesis treated laminectomy alone. @ follow-up varying between 18 , 71 months after surgery, 20 out of 24 patients reported result. epstein reported on 290 patients treated on 25-year period. excellent results obtained in 69% , results in 13%. these optimistic reports not correlate return competitive employment rates, part dismal in spinal surgery series.

studies cohen show 25% of low pain sacroiliac joint in origin , diagnosis of sacroiliac joint disease overlooked physicians. studies ha, et al., show incidence of si joint degeneration in post-lumbar fusion surgery 75% @ 5 years post-surgery, based on imaging. studies depalma , liliang, et al., demonstrate 40-61% of post-lumbar fusion patients symptomatic si joint dysfunction based on diagnostic blocks.

in past 2 decades there has been dramatic increase in fusion surgery in u.s.: in 2001 on 122,000 lumbar fusions performed, 22% increase 1990 in fusions per 100,000 population, increasing estimate of 250,000 in 2003, , 500,000 in 2006. in 2003, national bill hardware fusion alone estimated have soared $2.5 billion year. patients continued pain after surgery not due above complications or conditions, interventional pain physicians speak of need identify pain generator i.e. anatomical structure responsible patient s pain. effective, surgeon must operate on correct anatomic structure, not possible determine source of pain. reason many patients chronic pain have disc bulges @ multiple spinal levels , physical examination , imaging studies unable pinpoint source of pain. in addition, spinal fusion itself, particularly if more 1 spinal level operated on, may result in adjacent segment degeneration . thought occur because fused segments may result in increased torsional , stress forces being transmitted intervertebral discs located above , below fused vertebrae. pathology 1 reason behind development of artificial discs possible alternative fusion surgery. fusion surgeons argue spinal fusion more time-tested, , artificial discs contain metal hardware unlikely last long biological material without shattering , leaving metal fragments in spinal canal. these represent different schools of thought. (see discussion on disc replacement infra.)

another highly relevant consideration increasing recognition of importance of chemical radiculitis in generation of pain. primary focus of surgery remove pressure or reduce mechanical compression on neural element: either spinal cord, or nerve root. increasingly recognized pain, rather being solely due compression, may instead entirely due chemical inflammation of nerve root. has been known several decades disc herniations result in massive inflammation of associated nerve root. in past 5 years increasing evidence has pointed specific inflammatory mediator of pain. inflammatory molecule, called tumor necrosis factor-alpha (tnf), released not herniated or protruding disc, in cases of disc tear (annular tear), facet joints, , in spinal stenosis. in addition causing pain , inflammation, tnf may contribute disc degeneration. if cause of pain not compression, rather inflammation mediated tnf, may explain why surgery might not relieve pain, , might exacerbate it, resulting in fbss.

smoking

ct scan showing markedly thickened ligamentum flavum (yellow ligament) causing spinal stenosis in lumbar spine.

recent studies have shown cigarette smokers routinely fail spinal surgery, if goal of surgery decrease of pain , impairment. many surgeons consider smoking absolute contraindication spinal surgery. nicotine appears interfere bone metabolism through induced calcitonin resistance , decreased osteoblastic function. may restrict small blood vessel diameter leading increased scar formation.

there association between cigarette smoking, pain , chronic pain syndromes of types.

in report of 426 spinal surgery patients in denmark, smoking shown have negative effect on fusion , overall patient satisfaction, no measurable influence on functional outcome.

there validation of hypothetical assumption postoperative smoking cessation helps reverse impact of cigarette smoking on outcome after spinal fusion. if patients cease cigarette smoking in immediate post operative period, there positive impact on success.

regular smoking in adolescence associated low pain in young adults. pack-years of smoking showed exposure-response relationship among girls.

a recent study suggested cigarette smoking adversely affects serum hydrocodone levels. prescribing physicians should aware in cigarette smokers, serum hydrocodone levels might not detectable.

in study denmark reviewing many reports in literature, concluded smoking should considered weak risk indicator , not cause of low pain. in multitude of epidemiologic studies, association between smoking , low pain has been reported, variations in approach , study results make literature difficult reconcile. in massive study of 3482 patients undergoing lumbar spine surgery national spine network, comorbidities of (1) smoking, (2) compensation, (3) self reported poor overall health , (4) pre-existing psychological factors predictive in high risk of failure. followup carried out @ 3 months , 1 year after surgery. pre-operative depressive disorders tended not well.

smoking has been shown increase incidence of post operative infection decrease fusion rates. 1 study showed 90% of post operative infections occurred in smokers, myonecrosis (muscle destruction) around wound.