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Background context The North American Spine Society's (NASS) Evidence Based Clinical Guideline for the Diagnosis and Treatment of Low Back Pain features evidence-based recommendations for diagnosing and treating adult patients with nonspecific low back pain. The guideline is intended to reflect contemporary treatment concepts for nonspecific low back pain as reflected in the highest quality clinical literature available on this subject as of February 2016. PURPOSE The purpose of the guideline is to provide an evidence-based educational tool to assist spine specialists when making clinical decisions for adult patients with nonspecific low back pain. This article provides a brief summary of the evidence-based guideline recommendations for diagnosing and treating patients with this condition. Study design This is a guideline summary review. Methods This guideline is the product of the Low Back Pain Work Group of NASS’ Evidence-Based Clinical Guideline Development Committee. The methods used to develop this guideline are detailed in the complete guideline and technical report available on the NASS website. In brief, a multidisciplinary work group of spine care specialists convened to identify clinical questions to address in the guideline. The literature search strategy was developed in consultation with medical librarians. Upon completion of the systematic literature search, evidence relevant to the clinical questions posed in the guideline was reviewed. Work group members utilized NASS evidentiary table templates to summarize study conclusions, identify study strengths and weaknesses, and assign levels of evidence. Work group members participated in webcasts and in-person recommendation meetings to update and formulate evidence-based recommendations and incorporate expert opinion when necessary. The draft guideline was submitted to an internal and external peer review process and ultimately approved by the NASS Board of Directors. Results Eighty-two clinical questions were addressed, and the answers are summarized in this article. The respective recommendations were graded according to the levels of evidence of the supporting literature. Conclusions The evidence-based clinical guideline has been created using techniques of evidence-based medicine and best available evidence to aid practitioners in the diagnosis and treatment of adult patients with nonspecific low back pain. The entire guideline document, including the evidentiary tables, literature search parameters, literature attrition flowchart, suggestions for future research, and all of the references, is available electronically on the NASS website at https://www.spine.org/ResearchClinicalCare/QualityImprovement/ClinicalGuidelines.aspx

Object The objective of this systematic review was to use evidence-based medicine to delineate the natural history of cervical spondylotic myelopathy (CSM) and identify factors associated with clinical deterioration. Methods The National Library of Medicine and Cochrane Database were queried using MeSH headings and keywords relevant to the natural history of CSM. Abstracts were reviewed and studies meeting the inclusion criteria were selected. The guidelines group assembled an evidentiary table summarizing the quality of evidence (Classes I–III). Disagreements regarding the level of evidence were resolved through an expert consensus conference. The group formulated recommendations that contained the degree of strength based on the Scottish Intercollegiate Guidelines network. Validation was done through peer review by the Joint Guidelines Committee of the American Association of Neurological Surgeons and the Congress of Neurological Surgeons. Results The natural history of CSM is mixed: it may manifest as a slow, stepwise decline or there may be a long period of quiescence (Class III). Long periods of severe stenosis are associated with demyelination and may result in necrosis of both gray and white matter. With severe and/or long lasting CSM symptoms, the likelihood of improvement with nonoperative measures is low. Objectively measurable deterioration is rarely seen acutely in patients younger than 75 years of age with mild CSM (modified Japanese Orthopaedic Association scale score > 12; Class I). In patients with cervical stenosis without myelopathy, the presence of abnormal electromyography findings or the presence of clinical radiculopathy is associated with the development of symptomatic CSM in this patient population (Class I). Conclusions The natural history of CSM is variable, which may affect treatment decisions.

Object The objective of this systematic review was to use evidence-based medicine to assess whether preoperative imaging or electromyography (EMG) predicts surgical outcomes in patients undergoing cervical surgery. Methods The National Library of Medicine and Cochrane Database were queried using MeSH headings and keywords relevant to the preoperative imaging and EMG. Abstracts were reviewed after which studies meeting inclusion criteria were selected. The guidelines group assembled an evidentiary table summarizing the quality of evidence (Classes I–III). Disagreements regarding the level of evidence were resolved through an expert consensus conference. The group formulated recommendations that contained the degree of strength based on the Scottish Intercollegiate Guidelines network. Validation was done through peer review by the Joint Guidelines Committee of the American Association of Neurological Surgeons/Congress of Neurological Surgeons. Results Preoperative MR imaging and CT myelography are successful in confirming clinical radiculopathy (Class II). Multilevel T2 hyperintensity, T1 focal hypointensity combined with T2 focal hyperintensity, and spinal cord atrophy each convey a poor prognosis (Class III). There is conflicting data concerning whether focal T2 hyperintensity or cervical stenosis are associated with a worse outcome. Electromyography has mixed utility in predicting outcome (Class III). Conclusions Magnetic resonance imaging or CT myelography are important for preoperative assessment. Magnetic resonance imaging may be helpful in assessing prognosis, whereas EMG has mixed utility in assessing outcome.

Object The objective of this systematic review was to use evidence-based medicine to identify the indications and utility of anterior cervical nerve root decompression. Methods The National Library of Medicine and Cochrane Database were queried using MeSH headings and key words relevant to surgical management of cervical radiculopathy. Abstracts were reviewed after which studies meeting inclusion criteria were selected. The guidelines group assembled an evidentiary table summarizing the quality of evidence (Classes I–III). Disagreements regarding the level of evidence were resolved through an expert consensus conference. The group formulated recommendations that contained the degree of strength based on the Scottish Intercollegiate Guidelines network. Validation was done through peer review by the Joint Guidelines Committee of the American Association of Neurological Surgeons/Congress of Neurological Surgeons. Results Anterior nerve root decompression via anterior cervical discectomy (ACD) with or without fusion for radiculopathy is associated with rapid relief (3–4 months) of arm/neck pain, weakness, and/or sensory loss compared with physical therapy (PT) or cervical collar immobilization. Anterior cervical discectomy and ACD with fusion (ACDF) are associated with longer term (12 months) improvement in certain motor functions compared to PT. Other rapid gains observed after anterior decompression (diminished pain, improved sensation, and improved strength in certain muscle groups) are also maintained over the course of 12 months. However, comparable clinical improvements with PT or cervical immobilization therapy are also present in these clinical modalities (Class I). Conflicting evidence exists as to the efficacy of anterior cervical foraminotomy with reported success rates of 52–99% but recurrent symptoms as high as 30% (Class III). Conclusions Anterior cervical discectomy, ACDF, and anterior cervical foraminotomy may improve cervical radicular symptoms. With regard to ACD and ACDF compared to PT or cervical immobilization, more rapid relief (within 3–4 months) may be seen with ACD or ACDF with maintenance of gains over the course of 12 months (Class I). Anterior cervical foraminotomy is associated with improvement in clinical function but the quality of data are weaker (Class III), and there is a wide range of efficacy (52–99%).

Object The objective of this systematic review was to use evidence-based medicine to examine the efficacy of posterior laminoforaminotomy in the treatment of cervical radiculopathy. Methods The National Library of Medicine and Cochrane Database were queried using MeSH headings and key words relevant to posterior laminoforaminotomy and cervical radiculopathy. Abstracts were reviewed, and studies meeting inclusion criteria were selected. The guidelines group assembled an evidentiary table summarizing the quality of evidence (Classes I–III). Disagreements regarding the level of evidence were resolved through an expert consensus conference. The group formulated recommendations which contained the degree of strength based on the Scottish Intercollegiate Guidelines network. Validation was done through peer review by the Joint Guidelines Committee of the American Association of Neurological Surgeons/Congress of Neurological Surgeons. Results Posterior laminoforaminotomy improves clinical outcome in the treatment of cervical radiculopathy resulting from soft lateral cervical disc displacement or cervical spondylosis with resulting narrowing of the lateral recess. All studies were Class III. The most frequent design flaw involved the lack of utilization of validated outcomes measures. In addition, few historical studies included a detailed preoperative analysis of the patients. As such, the vast majority of studies that included both pre- and postoperative assessments with legitimate outcomes measures have been performed since 1990. Conclusions Posterior laminoforaminotomy is an effective treatment for cervical radiculopathy.

Object The objective of this systematic review was to use evidence-based medicine to examine the efficacy of cervical laminectomy and fusion for the treatment of cervical spondylotic myelopathy (CSM). Methods The National Library of Medicine and Cochrane Database were queried using MeSH headings and keywords relevant to cervical laminectomy, fusion, and CSM. Abstracts were reviewed, after which studies that met the inclusion criteria were selected. The guidelines group assembled an evidentiary table summarizing the quality of evidence (Class I–III). Disagreements regarding the level of evidence were resolved through an expert consensus conference. The group formulated recommendations which contained the degree of strength based on the Scottish Intercollegiate Guidelines network. Validation was done through peer-review by the Joint Guidelines Committee of the American Association of Neurological Surgeons/Congress of Neurological Surgeons. Results Cervical laminectomy with fusion (arthrodesis) improves functional outcome in patients with CSM and ossification of the posterior longitudinal ligament (OPLL). Functional improvement is similar to laminectomy or laminoplasty for patients with CSM and OPLL. In contrast to laminectomy, cervical laminectomy with fusion it is not associated with late deformity (Class III). Conclusions Laminectomy with fusion (arthrodesis) is an effective strategy to improve functional outcome in CSM and OPLL.

Object The objective of this systematic review was to use evidence-based medicine to determine the efficacy of interbody graft techniques. Methods The National Library of Medicine and Cochrane Database were queried using MeSH headings and keywords relevant to cervical interbody grafting. Abstracts were reviewed and studies that met the inclusion criteria were selected. The guidelines group assembled an evidentiary table summarizing the quality of evidence (Classes I–III). Disagreements regarding the level of evidence were resolved through an expert consensus conference. The group formulated recommendations that contained the degree of strength based on the Scottish Intercollegiate Guidelines network. Validation was done through peer review by the Joint Guidelines Committee of the American Association of Neurological Surgerons/Congress of Neurological Surgeons. Results Autograft bone harvested from the iliac crest, allograft bone from either cadaveric iliac crest or fibula, or titanium cages and rectangular fusion devices, with or without the use of autologous graft or substitute, have been successful in creating arthrodesis after 1- or 2-level anterior cervical discectomy with fusion (Class II). Alternatives to autograft, allograft, or titanium cages include polyetheretherketone cages and carbon fiber cages (Class III). Polyetheretherketone cages have been used successfully with or without hydroxyapatite for anterior cervical discectomy with fusion. Importantly, recombinant human bone morphogenic protein-2 carries a complication rate of up to 23–27% (especially local edema) compared with 3% for a standard approach. Conclusions Current evidence does not support the routine use of interbody grafting for cervical arthrodesis. Multiple strategies for interbody grafting have been successful with Class II evidence supporting the use of autograft, allograft, and titanium cages.

Background Context The North American Spine Society's (NASS) Evidence-Based Clinical Guideline for the Diagnosis and Treatment of Degenerative Lumbar Spondylolisthesis features evidence-based recommendations for diagnosing and treating degenerative lumbar spondylolisthesis. The guideline updates the 2008 guideline on this topic and is intended to reflect contemporary treatment concepts for symptomatic degenerative lumbar spondylolisthesis as reflected in the highest quality clinical literature available on this subject as of May 2013. The NASS guideline on this topic is the only guideline on degenerative lumbar spondylolisthesis included in the Agency for Healthcare Research and Quality's National Guideline Clearinghouse (NGC). Purpose The purpose of this guideline is to provide an evidence-based educational tool to assist spine specialists when making clinical decisions for patients with degenerative lumbar spondylolisthesis. This article provides a brief summary of the evidence-based guideline recommendations for diagnosing and treating patients with this condition. Study Design A systematic review of clinical studies relevant to degenerative spondylolisthesis was carried out. Methods This NASS spondyolisthesis guideline is the product of the Degenerative Lumbar Spondylolisthesis Work Group of NASS' Evidence-Based Guideline Development Committee. The methods used to develop this guideline are detailed in the complete guideline and technical report available on the NASS website. In brief, a multidisciplinary work group of spine care specialists convened to identify clinical questions to address in the guideline. The literature search strategy was developed in consultation with medical librarians. Upon completion of the systematic literature search, evidence relevant to the clinical questions posed in the guideline was reviewed. Work group members used the NASS evidentiary table templates to summarize study conclusions, identify study strengths and weaknesses, and assign levels of evidence. Work group members participated in webcasts and in-person recommendation meetings to update and formulate evidence-based recommendations and incorporate expert opinion when necessary. The draft guidelines were submitted to an internal peer review process and ultimately approved by the NASS Board of Directors. Upon publication, the Degenerative Lumbar Spondylolisthesis guideline was accepted into the NGC and will be updated approximately every 5 years. Results Twenty-seven clinical questions were addressed in this guideline update, including 15 clinical questions from the original guideline and 12 new clinical questions. The respective recommendations were graded by strength of the supporting literature, which was stratified by levels of evidence. Twenty-one new or updated recommendations or consensus statements were issued and 13 recommendations or consensus statements were maintained from the original guideline. Conclusions The clinical guideline was created using the techniques of evidence-based medicine and best available evidence to aid practitioners in the care of patients with degenerative lumbar spondylolisthesis. The entire guideline document, including the evidentiary tables, literature search parameters, literature attrition flow chart, suggestions for future research, and all of the references, is available electronically on the NASS website at https://www.spine.org/Pages/ResearchClinicalCare/QualityImprovement/ClinicalGuidelines.aspx and will remain updated on a timely schedule.

Cervical spine kyphotic deformities are common sequelae of degenerative disease. Patients may present with a combination of symptoms including myelopathy and radiculopathy. We retrospectively studied a cohort of 78 patients who underwent decompression and reconstruction of the cervical spine for such deformities. Decompression and reconstruction were done by vertebrectomy (51%), multilevel interbody arthrodesis (40%), posterior decompression and reconstruction (4%), and circumferential surgery (5%). In those patients whose pretreatment kyphotic deformity was more severe than -15 degrees, 10 of 27 required revision compared with only 4 of 51 patients whose initial deformities were less than -15 degrees (p

At the present time, there is no Class I or II medical evidence to indicate that the appearance of a radiographic fusion is significantly associated with improved functional outcomes. The majority of Class III medical evidence does suggest that successful radiographic fusion is associated with improved clinical outcomes. It is widely acknowledged that this relationship is not perfect.

The best medical evidence available in the literature confirms the utility of fusion for improving patient outcomes following decompression for stenosis associated with spondylolisthesis. The majority of evidence from other studies comparing outcomes after decompression alone or decompression combined with PLF in patients with stenosis and spondylolisthesis also favors the performance of PLF. The medical evidence regarding the use of pedicle screw fixation in this patient population is rated as Class III and is inconsistent. A consistent benefit associated with the use of pedicle screw fixation has been reported in patients with preoperative instability or kyphosis. Iatrogenic instability following decompression is associated with poor outcomes and may also be treated with PLF involving supplemental instrumentation. The precise definition of instability or kyphosis has varied among researchers and requires further study.

In summary, there is no meaningful evidence in the medical literature that the use of epidural injections is of any long-term value in the treatment of patients with chronic low-back pain. The literature does indicate that the use of lumbar epidural injections can provide short-term relief in selected patients with chronic low-back pain. There is evidence that suggests that facet joint injections can be used to predict outcome after RF ablation of a facet joint. The predictive ability of facet joint injections does not appear to apply to lumbar fusion surgery. No evidence exists to support the effectiveness of facet injections in the treatment of patients with chronic low-back pain. There is conflicting evidence suggesting that the use of local TPIs can be effective for the short-term relief of low-back pain. There are no data to suggest that TPIs with either steroids or anesthetics alone provide lasting benefit for patients suffering from chronic low-back pain.

There is no convincing medical evidence to support the routine use of lumbar fusion at the time of a primary lumbar disc excision. There is conflicting Class III medical evidence regarding the potential benefit of the addition of fusion in this circumstance. Therefore, the definite increase in cost and complications associated with the use of fusion are not justified. Patients with preoperative lumbar instability may benefit from fusion at the time of lumbar discectomy; however, the incidence of such instability appears to be very low (5%) in the general lumbar disc herniation population. Patients who suffer from chronic low-back pain, or are heavy laborers or athletes with axial low-back pain, in addition to radicular symptoms may also be candidates for fusion at the time of lumbar disc excision. Patients with a recurrent disc herniation have been treated successfully with both reoperative discectomy and reoperative discectomy combined with fusion. In patients with a recurrent lumbar disc herniation with associated spinal deformity, instability, or associated chronic low-back pain, consideration of fusion in addition to reoperative discectomy is recommended.

Functional disability secondary to acute low-back pain, chronic low-back pain, lumbar stenosis, and lumbar disc disease may be reliably and validly assessed using functional outcome surveys that are valid, reliable, and responsive. Outcome instruments supported by Class I and Class II medical evidence for the evaluation of low-back pain include the Spinal Stenosis Survey of Stucki, Waddell-Main, RMDQ, DPQ, QPDS, SIP, Million Scale, LBPR Scale, ODI, and CBSQ. Many of these outcome measures have been applied to patients who have been treated with lumbar fusion for degenerative lumbar disease and have proven to be valid and responsive; however, the reliability of these instruments has never been specifically assessed in the lumbar fusion patient population. Patient satisfaction surveys have been used to measure outcome following lumbar fusion. Their usefulness resides in their insight into patient attitudes toward the treatment experience but is limited because of their inability to measure responsiveness and the lack of information on their reliability.

Summary of studies involving pedicle screw fixation in patients with degenerative lumbar disease* Authors & YearClassDescriptionCommentLorenz, et al., 1991II fusionProspective randomized study of 68 patients w/ $ 6-mo history of disabling back pain. Group I (29) PS instrumentation improves fusion rates & return toII outcome PLF w/o instrumentation. Group II (39) PLF 1PS. All cases were 1 level. Mean FU 26 mos.Fu- work for PLF.(return to work)sion based on flexion–extension x-ray was 59% Group I & 100% Group II. Return to similar work was 31% in Group I & 72% Group II.Bernhardt, et al., 1992IIIRetrospective study of 47 patients w/ PLF, 21 w/ PSs & 27 w/o. 18 of 21 PS had FU. Independent PLF w/o PS is as effective & safer than fusion w/PS.retrospective review. Assignment of patients into the 2 groups is poorly defined. Pseudarthrosis did not significantly differ btwn the 2 groups (PS 22%; nonscrew group, 26%. No p value given). 12 (67%) of 18 PS & 19 (70%) of 27 uninstrumented PS patients had good or excellent results. 2 PS patients had postop leg dysesthesias, 1 requiring hardware removal (5%). No uninstrumented cases experienced dysesthesias. Bridwell, et al., 1993III fusion Prospective randomized 44 patients w/ DS. Patients w/ .10˚ or 3 mm movement were instrumented. PLF 1PS decreases chances of slip progression, in-III outcomeMean FU 3 yrs & 2 mos, min 24 mos. Group I no fusion (9), Group II PLF no PS (10), Group III creases fusion rate, & increased patient satisfaction.PLF 1PS (24). Fusion based on Lenke–Bridwell system (static plain x-ray). Functional outcome not validated, emphasized claudication. Results: spondylolisthesis progression worse in Group I 1II than III, p = 0.001. Fusion rate higher in III than II, p = 0.002. Zdeblick, 1993I fusionAprospective randomized study of 124 patients divided into 3 groups. Group 1 w/ PLF onlay fusion Clinical outcome directly related to fusion rate. In-(51), Group 2 w/ PLF w/ semirigid PS (35), Group 3 w/ PLF w/ rigid PS system (37). FU was 9–28 creasing stiffness of instrumentation leads to mos (mean 16 mos). Fusion status determined by plain radiographs: flexion–extension views at 1 yr. higher fusion rates.Fusion rates 65% Group 1, 77% Group 2, & 95% Group 3. Differences btwn 1 & 3 (p = 0.002) & 1 & 2 (p = 0.034) were statistically significant. Clinical outcomes assessed w/ a nonstandard measure grading patients as excellent, good, fair, or poor. At the latest FU, mean 16 mos, Group 1 had 49% ex-cellent, 22% good, & 29% fair or poor. Group II was 60, 29, & 11%. Group III 70, 24, & 5%.Schwab, et al., 1995III fusionRetrospective cohort study w/ FU of 2 yrs. Fusion assessed w/ x-ray. Group I 126 patients w/ PLF alone. PS fixation improves fusion rate vs uninstrumented Group II 89 patients augmented w/ PS. Fusion rate assessed by dynamic x-ray: 65% & 91% (p ,fusion. No increase in complication rate: outcome 0.001). Complications: pseudarthrosis lower in the instrumentation group. Outcomes assessed w/ scale was nonstandard but instrumented fusionsnonstandardized measure w/ instrumented group faring better.did better.Fischgrund, et al., 1997I fusionProspective randomized 76 patients spondylolisthesis & spinal stenosis. All patients had posterolatPLF w/ PS is associated w/ higher fusion rate, but no II outcomeintertransverse process arthrodesis. Patients were randomized to a segmental transpedicular instru- difference in clinical outcome.mented or noninstrumented group. Results: 67 patients w/ 2-yr FU. Clinical outcome was excellent or good in 76% of patients w/ instrumentation & in 85% w/o instrumentation (p = 0.45). Fusion in 82% of the instrumented vs 45% of noninstrumented cases (p = 0.0015). Overall, successful fusion did not influence outcome (p = 0.435). Katz, et al., 1997IIIProspective nonrandomized study of 272 patients w/ decompression for lumbar stenosis. Laminectomy Noninstrumented arthrodesis resulted in superior vs laminectomy w/ PLF (37) vs laminectomy 1PS PLF (41). Noninstrumented arthrodesis associ-relief of back pain after 6 & 24 mos.ated w/ superior relief of LBPat 6 (p = 0.004) and 24 mos (p = 0.01). Findings limited by small no. of participating surgeons; modest sample size produced p values of borderline significance& the potential confounding bias of choice of treatment w/ fusion being surgeon dependent.Thomsen, et al., 1997II fusionProspective randomized trial of 130 patients w/ Grade 1 or 2 degenerative or isthmic spondylolisthesis:Instrumentation does not improve results of PLF. I outcome66 patients w/ PLF & 64 patients w/ PLF 1PS. 98% of patients had 2-yr FU. Fusion rates by dy-namic radiographs were not significantly different btwn groups. DPQ improved significantly in both groups but no significant difference btwn groupsexcept for the daily activities subsection of the DPQwhich was improved in the instrumented group (p,0.05). Instrumentation increased op time, blood loss, & early reop rate significantly. Functional outcome was not significantly improved w/ use of PSexcept when patients w/ PS had concomitant decompressions (p ,0.05). France, et al., 1999III fusion & Prospective randomized 71 patients PLF 6PS. No statistical difference in patient-reported outcome No difference in outcome or arthrodesis rate of PLF outcomebtwn the 2 groups. Slight nonsignificant trend toward increasedradiographic fusion rate in the group vs PLF 1PS.w/ instrumentation that did not correlate w/ an increased patient-reported improvement rate. Class III due to nonstandard outcome measures, large dropout rate, & poor x-ray criteria for fusion.Fritzell, et al., 2001I functionalProspective randomized multicenter study of 294 patients. Group 1 (PLF, 73), Group 2 (PLF 1PS, 74), & Comparison of noninstrumented fusion vs PLF vs III radiographicGroup 3 (PLF 1 PS 1interbody fusion, 75:ALIF [56] or PLIF [19]). Group 4 nonop (72). Results: PLF 1PS vs interbody fusion. No difference in FU 201 (91%) of 222 patients after 2 yrs. All surgical techniques reduced pain & decreased disabilityoutcome. Interbody fusion had highest fusion rates substantially, but no significant differences found among groups. Groups 2 & 3 consumed signifi-& complication rates followed by PLF 1PS.cantly more resources:op time, blood transfusions, & stay. Early complication rate 6% in Group 1, 16% in Group 2, & 31% in Group 3. Fusion rate by plain radiographs: 72% in Group 1, 87% in Group 2, & 91% in Group 3. High complication rate of instrumentation related to 9 patients w/ PS removal for new onset radiculopathy. At the time of reop only 3 actually had cortical wall breach.

The detail and information obtained from neuroimaging have improved greatly over the last two decades with the advent of magnetic resonance imaging (MRI) and angiography (MRA). In the last decade, advances in computer technology and tomography have produced angiographic images from computed tomography (CTA). Despite these advances, the basic evaluation of traumatic vascular injury relies on catheter angiography. With advances in critical care and neuroimaging techniques, it has become feasible to have critically ill patients undergo MR and CT imaging. MRA and CTA provide the ability to diagnose rapidly and noninvasively vascular injuries that may predispose to stroke. The purpose of this article is to review briefly these advances and their relevance to traumatic brain injury for the neurosurgical practitioner.

To determine preoperative and operative factors associated with the need for unanticipated critical care management and prolonged hospitalization after cervical spine surgery.Retrospective, case controlled study with data collection over 5 yrs.Intensive care unit at a Veterans Affairs hospital.A total of 109 patients who underwent elective cervical decompression for degenerative disease.Anterior or posterior cervical spine surgery.Data were recorded with regard to pre- and postoperative neurologic function, extent of surgery, length and cost of hospitalization and critical care, and preoperative co-morbidities. Of 109 patients, 16 (15%) required critical care management in the early postoperative phase (group I). The remainder (n = 93) represented group II. Group I had an average hospital stay of 18.5 days as compared with 6.1 days for group II (p.001) and a cost difference of approximately $26,000. The incidence of preexisting myelopathy (69%) and the extent of decompression (2.38 levels) were greater in group I than group II (27%, p.005; 1.67 levels, p.01). The presence of pulmonary disease (p.03), hypertension (p.02), cardiovascular disease (p.05), and diabetes mellitus (p.002) all were associated with the need for critical care management and longer hospitalization.In those patients undergoing decompressive cervical surgery for degenerative disease, the following factors were linked to the need for unanticipated, postoperative critical care and longer hospitalization: multilevel decompression, preexisting myelopathy, pulmonary disease, cardiovascular disease, hypertension, and diabetes mellitus.

Vasogenic edema after oxidative injury has been accompanied by intracellular accumulation of serum proteins and nuclear damage. This study sought to determine whether serum protein accumulation, along with other markers of brain injury, was present after exposure to intracerebral hemolysate, an oxidant model of intracerebral hemorrhage (ICH). Saline (n = 24) or hemolysate (n = 30) was injected into the caudate-putamen of adult Sprague-Dawley rats. Compared with saline, hemolysate deposition was associated with intracellular accumulation of serum proteins as evidenced by Evans blue uptake in neurons and microglia at 4 and 24 hours. Intracellular Evans blue colocalized with DNA fragmentation detected by nick end-labeling and whose presence was confirmed by gel electrophoresis. Immunoblots of cytosolic fractions confirmed cytochrome c release. Immunostaining established colocalization of cytosolic cytochrome c and intracellular Evans blue at 4 hours. At 24 hours, cytosolic cytochrome c was evident in astrocytes surrounding Evans blue-positive cells. Immunoblot analysis and immunostaining revealed HSP70 induction at 24 hours in regions adjacent to intracellular serum accumulation. Neuronal accumulation of extravasated serum proteins in this model of ICH was associated with cytochrome c release, DNA fragmentation, and cell death. Stress protein induction in adjacent regions suggested that vasogenic edema might have exacerbated cellular dysfunction and cell death after ICH.

Background and Purpose —We sought to investigate the mechanisms for oxidative injury caused by subarachnoid hemolysate, a pro-oxidant. Methods —Injection of 50 μL of subarachnoid hemolysate or saline was performed in CD1 mice (n=75), mutant mice deficient in Mn–superoxide dismutase ( Sod2 +/−; n=23), and their wild-type littermates (n=23). Subcellular location of cytochrome c was studied by immunocytochemistry, immunofluorescence, and immunoblotting of cellular fractions. DNA fragmentation was assessed though DNA laddering and terminal deoxynucleotidyl transferase–mediated dUTP-biotin nick end-labeling (TUNEL). Cell death was examined through basic histology. Results —Cytochrome c immunoreactivity was present in the cytosol of neurons at 2 hours after hemolysate injection and increased by 4 hours compared with saline-injected animals ( P c was more abundant in Sod2 +/− mutants. DNA fragmentation was evident at 24 hours, but not 4 hours, after hemolysate injection as determined by DNA laddering and TUNEL staining ( P c and iron. In Sod2 +/− mutants, the extent of fragmentation was increased as determined by TUNEL staining (52% increase; P P Sod2 +/− mutants, cell death was increased by 51% compared with wild-type littermates ( P Conclusions —These results demonstrate that subarachnoid blood products are associated with the presence of cytochrome c in the cytosol and subsequent cell death in neurons. It appears that Mn–superoxide dismutase plays a role in preventing cell death after exposure to subarachnoid blood products.

Background: Overall prognosis of nonpenetrating traumatic brain hemorrhage may be predicted by neurologic function days after insult. The relationship between immediate function and outcome has not been examined for infratentorial traumatic brain hemmorhage (iTBH) identified on computed tomographic (CT) scan. Given the severity of brain stem injury, it is conceivable that immediate function may be predictive. Methods: A retrospective review of 1,500 brain injuries occurring at our institution identified 18 patients (1.2%) with iTBH on CT scan (eight brain stem, five cerebellum, five both). Demographics, supratentorial injuries, and outcome at 6 months (Glasgow Outcome Scale) were recorded. Results: Initial Glasgow Coma Scale (GCS) in 11 patients was less than 5 (group I). Seven patients had GCS scores greater than or equal to 6 (group II). Nine patients in group I either died or were vegetative. In group II, one died; none were vegetative (p < 0.02). Regression analysis demonstrated a strong correlation between initial GCS and Glasgow Outcome Scale scores at 6 months for all patients (p < 0.001) Conclusion: We conclude that initial GCS score may be predictive of long-term outcome in patients with CT scan evidence of iTBH-a relationship to be explored further for prognostic information.

Free radicals are highly reactive molecules implicated in the pathology of traumatic brain injury and cerebral ischemia, through a mechanism known as oxidative stress. After brain injury, reactive oxygen and reactive nitrogen species may be generated through several different cellular pathways, including calcium activation of phospholipases, nitric oxide synthase, xanthine oxidase, the Fenton and Haber-Weiss reactions, by inflammatory cells. If cellular defense systems are weakened, increased production of free radicals will lead to oxidation of lipids, proteins, and nucleic acids, which may alter cellular function in a critical way. The study of each of these pathways may be complex and laborious since free radicals are extremely short-lived. Recently, genetic manipulation of wild-type animals has yielded species that over- or under-express genes such as, copper-zinc superoxide dismutase, manganese superoxide dismutase, nitric oxide synthase, and the Bcl-2 protein. The introduction of the species has improved the understanding of oxidative stress. We conclude here that substantial experimental data links oxidative stress with other pathogenic mechanisms such as excitotoxicity, calcium overload, mitochondrial cytochrome c release, caspase activation, and apoptosis in central nervous system (CNS) trauma and ischemia, and that utilization of genetically manipulated animals offers a unique possibility to elucidate the role of free radicals in CNS injury in a molecular fashion.

Current experimental evidence demonstrates the development of ischemic regions adjacent to and spatially remote from an intracerebral hematoma. The cause of this ischemia is uncertain. Because ischemia is a known inducer of stress genes, we investigated the induction of two stress proteins, heme oxygenase (HO)-1 and heat shock protein (Hsp) 70, after intracerebral hemorrhage in the rat.Immunocytochemistry for HO-1, Hsp70, and HO-2, the constitutive isoform of the HO enzyme, was performed 1, 2, and 4 days after striatal injection of saline, whole blood, or lysed blood. Immunocytochemistry for HO-1, HO-2, and Hsp70 was also performed 1 day after cortical injection of saline, whole blood, or lysed blood.After striatal injection of lysed and whole blood, the HO-1 protein was induced in glia throughout the hemisphere ipsilateral to the hematoma, and HO-1 immunoreactivity persisted for at least 4 days. After cortical injection of lysed and whole blood, HO-1 was induced in glia throughout the neocortex. Neuronal induction of HO-1 was also observed after cortical injection of lysed blood but not whole blood or saline. After striatal injection of lysed blood, Hsp70 was induced in glia surrounding the hematoma and in neurons from the neocortex overlying the hematoma and the striatum adjacent to the hematoma. After cortical injection of lysed blood, Hsp70 was induced in neurons throughout the neocortex and hippocampus bilaterally. In contrast, after whole blood and saline injection into cortex, Hsp70 induction was observed only in scattered neurons surrounding the hematoma cavity.Our results demonstrate that blood in the brain parenchyma induces the HO-1 stress protein but does not significantly alter HO-2 immunostaining. Our results also demonstrate that lysed blood induces Hsp70 in multiple regions of the brain and that the stress response of the brain differs depending on whether lysed blood is injected into the cortex or striatum. These results suggest that blood lysis may play an unforeseen role in the stress response of the brain to intracerebral hemorrhage.

Background context The North American Spine Society's (NASS) Evidence-Based Clinical Guideline on Antibiotic Prophylaxis in Spine Surgery provides evidence-based recommendations to address key clinical questions regarding the efficacy and the appropriate antibiotic prophylaxis protocol to prevent surgical site infections in patients undergoing spine surgery. The guideline is intended to address these questions based on the highest quality clinical literature available on this subject as of June 2011. Purpose Provide an evidence-based educational tool to assist spine surgeons in preventing surgical site infections. Study design Systematic review and evidence-based clinical guideline. Methods This guideline is a product of the Antibiotic Prophylaxis in Spine Surgery Work Group of NASS Evidence-Based Guideline Development Committee. The work group consisted of neurosurgeons and orthopedic surgeons who specialize in spine surgery and are trained in the principles of evidence-based analysis. A literature search addressing each question and using a specific search protocol was performed on English language references found in MEDLINE (PubMed), ACP Journal Club, Cochrane Database of Systematic Reviews Database of Abstracts of Reviews of Effectiveness, Cochrane Central Register of Controlled Trials, EMBASE (Drugs and Pharmacology), and Web of Science to identify articles published since the search performed for the original guideline. The relevant literature was then independently rated using the NASS-adopted standardized levels of evidence. An evidentiary table was created for each of the questions. Final recommendations to answer each clinical question were developed via work group discussion, and grades were assigned to the recommendations using standardized grades of recommendation. In the absence of Levels I to IV evidence, work group consensus statements have been developed using a modified nominal group technique, and these statements are clearly identified as such in the guideline. Results Sixteen clinical questions were formulated and addressed, and the answers are summarized in this article. The respective recommendations were graded by the strength of the supporting literature, which was stratified by levels of evidence. Conclusions The clinical guideline for antibiotic prophylaxis in spine surgery has been created using the techniques of evidence-based medicine and best available evidence to aid practitioners in the care of patients undergoing spine surgery. The entire guideline document, including the evidentiary tables, suggestions for future research, and all the references, is available electronically on the NASS Web site at http://www.spine.org/Pages/PracticePolicy/ClinicalCare/ClinicalGuidlines/Default.aspx and will remain updated on a timely schedule.

With increased use of magnetic resonance imaging (MRI), diagnosis of cavernous malformations (CMs) has become straightforward. Surgical excision is the treatment of choice for these lesions. These malformations, though, are often small and can be difficult to localize during surgery. In these cases, stereotactic resection with a frame-based system is recommended to aid in localization of the malformation. However, use of these frame-based systems can be time consuming for the surgeon and onerous for the patient. With the advent of frameless stereotactic systems, these problems can be circumvented. Therefore, stereotactic resection of 17 CMs was performed for 15 patients over the course of 2 years at our institution during an investigative trial of a frameless stereotactic device. Eight patients presented with seizures, five patients with hemorrhage, and two patients with progressive headaches. Twelve of fifteen patients had normal neurological examination results on presentation, whereas three patients had deficits resulting from intracranial hemorrhages. All patients underwent diagnostic MRI preoperatively. Fourteen lesions were found to be cortical and subcortical; the other three lesions were in the basal ganglia, lateral ventricle, and pons. Following resection, 11 of 15 patients improved. Two patients developed postoperative deficits shortly after resection. One patient with a preoperative neurological deficit remained unchanged, and one patient had a recurrence of a deficit several months following resection. Image-guided stereotactic resection provides for easy localization of small malformations without requiring the use of a stereotactic frame or retractor and is well suited for resection of cavernous malformations.

Object The objective of this systematic review was to use evidence-based medicine to identify valid, reliable, and responsive measures of functional outcome after treatment for cervical degenerative disease. Methods The National Library of Medicine and Cochrane Database were queried using MeSH headings and key words relevant to functional outcomes. Abstracts were reviewed after which studies meeting inclusion criteria were selected. The guidelines group assembled an evidentiary table summarizing the quality of evidence (Classes I–III). Disagreements regarding the level of evidence were resolved through an expert consensus conference. The group formulated recommendations that contained the degree of strength based on the Scottish Intercollegiate Guidelines network. Validation was done through peer review by the Joint Guidelines Committee of the American Association of Neurological Surgeons/Congress of Neurological Surgeons. Results Myelopathy Disability Index, Japanese Orthopaedic Association scale, 36-Item Short Form Health Survey, and gait analysis were found to be valid and reliable measures (Class II) for assessing cervical spondylotic myelopathy. The Patient-Specific Functional Scale, the North American Spine Society scale, and the Neck Disability Index were found to be reliable, valid, and responsive (Class II) for assessing radiculopathy for nonoperative therapy. The Cervical Spine Outcomes Questionnaire was a reliable and valid method (Class II) to assess operative therapy for cervical radiculopathy. Conclusions Several functional outcome measures are available to assess cervical spondylotic myelopathy and cervical radiculopathy.

Object The objective of this systematic review was to use evidence-based medicine to examine the efficacy of cervical laminoplasty in the treatment of cervical spondylotic myelopathy (CSM). Methods The National Library of Medicine and Cochrane Database were queried using MeSH headings and keywords relevant to cervical laminoplasty and CSM. Abstracts were reviewed and studies meeting the inclusion criteria were selected. The guidelines group assembled an evidentiary table summarizing the quality of evidence (Classes I–III). Disagreements regarding the level of evidence were resolved through an expert consensus conference. The group formulated recommendations that contained the degree of strength based on the Scottish Intercollegiate Guidelines network. Validation was done through peer review by the Joint Guidelines Committee of the American Association of Neurological Surgeons and Congress of Neurological Surgeons. Results Cervical laminoplasty has improved functional outcome in the setting of CSM or ossification of the posterior longitudinal ligament. Using the Japanese Orthopaedic Association scale score, ~ 55–60% average recovery rate has been observed (Class III). The functional improvement observed after laminoplasty may be limited by duration of symptoms, severity of stenosis, severity of myelopathy, and poorly controlled diabetes as negative risk factors (Class II). There is conflicting evidence regarding age, with 1 study citing it as a negative risk factor, and another not demonstrating this result. Conclusions Cervical laminoplasty is recommended for the treatment of CSM or ossification of the posterior longitudinal ligament (Class III).

Object The objective of this systematic review was to use evidence-based medicine to identify the best methodology for radiographic assessment of cervical subaxial fusion. Methods The National Library of Medicine and Cochrane Database were queried using MeSH headings and keywords relevant to cervical fusion. Abstracts were reviewed and studies meeting inclusion criteria were selected. The guidelines group assembled an evidentiary table summarizing the quality of evidence (Classes I–III). Disagreements regarding the level of evidence were resolved through an expert consensus conference. The group formulated recommendations that contained the degree of strength based on the Scottish Intercollegiate Guidelines network. Validation was done through peer review by the Joint Guidelines Committee of the American Association of Neurological Surgeons/Congress of Neurological Surgeons. Results Pseudarthrosis is best assessed through the absence of motion detected between the spinous processes on dynamic radiographs (Class II). The measurement of interspinous distance on dynamic radiographs of ≥ 2 mm is a more reliable indicator for pseudarthrosis than angular motion of 2° based on Cobb angle measurements (Class II). Similarly, it is also understood that the pseudarthrosis rate will increase as the threshold for allowable motion on dynamic radiographs decreases. The combination of interspinous distance measurements and identification of bone trabeculation is unreliable when performed by the treating surgeon (Class II). Identification of bone trabeculation on static radiographs should be considered a less reliable indicator of cervical arthrodesis than dynamic films (Class III). Conclusions Consideration should be given to dynamic radiographs and interspinous distance when assessing for pseudarthrosis.

Object The objective of this systematic review was to use evidence-based medicine to examine the diagnostic and therapeutic utility of intraoperative electrophysiological (EP) monitoring in the surgical treatment of cervical degenerative disease. Methods The National Library of Medicine and Cochrane Database were queried using MeSH headings and key words relevant to cervical spine surgery and EP monitoring. The guidelines group assembled an evidentiary table summarizing the quality of evidence (Classes I–III). The group formulated recommendations that contained the degree of strength based on the Scottish Intercollegiate Guidelines network. Validation was done through peer review by the Joint Guidelines Committee of the American Association of Neurological Surgeons/Congress of Neurological Surgeons. Results The reliance on changes in EP monitoring as an indication to alter a surgical plan or administer steroids has not been observed to reduce the incidence of neurological injury during routine surgery for cervical spondylotic myelopathy or cervical radiculopathy (Class III). However, there is an absence of study data examining the benefit of altering a surgical plan due to EP changes. Conclusions Although the use of EP monitoring may serve as a sensitive means to diagnose potential neurological injury during anterior spinal surgery for cervical spondylotic myelopathy, the practitioner must understand that intraoperative EP worsening is not specific—it may not represent clinical worsening and its recognition does not necessarily prevent neurological injury, nor does it result in improved outcome (Class II). Intraoperative improvement in EP parameters/indices does not appear to forecast outcome with reliability (conflicting Class I data).

Object The objective of this systematic review was to use evidence-based medicine to identify the best techniques for anterior cervical nerve root decompression. Methods The National Library of Medicine and Cochrane Database were queried using MeSH headings and keywords relevant to techniques for the surgical management of cervical radiculopathy. The guidelines group assembled an evidentiary table summarizing the quality of evidence (Classes I–III). The group formulated recommendations that contained the degree of strength based on the Scottish Intercollegiate Guidelines network. Validation was done through peer-review by the Joint Guidelines Committee of the American Association of Neurological Surgeons/Congress of Neurological Surgeons. Results Both anterior cervical discectomy (ACD) and anterior cervical discectomy with fusion (ACDF) are equivalent treatment strategies for 1-level disease with regard to functional outcome (Class II). Anterior cervical discectomy with fusion may achieve a more rapid reduction of neck and arm pain compared to ACD with a reduced risk of kyphosis, although functional outcomes may be similar. Anterior cervical discectomy with fusion is not a lasting means of increasing foraminal or disc height compared to ACD. Anterior cervical plating (ACDF with instrumentation) improves arm pain (but not other clinical parameters) better than ACDF in the treatment of 2-level disease (Class II). With respect to 1-level disease, plating may reduce the risk of pseudarthrosis and graft problems (Class III) but does not necessarily improve clinical outcome alone (Class II). Cervical arthroplasty is recommended as an alternative to ACDF in selected patients for control of neck and arm pain (Class II). Conclusions Anterior cervical discectomy, ACDF, and arthroplasty are effective techniques for addressing surgical cervical radiculopathy.

Object The objective of this systematic review was to use evidence-based medicine to examine the efficacy of anterior cervical surgery for the treatment of cervical spondylotic myelopathy (CSM). Methods The National Library of Medicine and Cochrane Database were queried using MeSH headings and key words relevant to anterior cervical surgery and CSM. Abstracts were reviewed, and studies meeting inclusion criteria were selected. The guidelines group assembled an evidentiary table summarizing the quality of evidence (Classes I–III). Disagreements regarding the level of evidence were resolved through an expert consensus conference. The group formulated recommendations that contained the degree of strength based on the Scottish Intercollegiate Guidelines network. Validation was done through peer review by the Joint Guidelines Committee of the American Association of Neurological Surgeons/Congress of Neurological Surgeons. Results Mild CSM (modified Japanese Orthopaedic Association [mJOA] scale scores > 12) responds in the short term (3 years) to either surgical decompression or nonoperative therapy (prolonged immobilization in a stiff cervical collar, “low-risk” activity modification or bed rest, and antiinflammatory medications) (Class II). More severe CSM responds to surgical decompression with benefits being maintained a minimum of 5 years and as long as 15 years postoperatively (Class III). Conclusions Treatment of mild CSM may involve surgical decompression or nonoperative therapy for the first 3 years after diagnosis. More severe CSM (mJOA scale score ≤ 12) should be considered for surgery depending upon the individual case. The shortcomings of this systematic review are that the group was not able to determine whether an mJOA scale score of 12 was indicative of a more severe CSM disease course, and whether patients who received nonsurgical treatment for 3 years had a significant probability for clinical deterioration after that time point.

Object The objective of this systematic review was to use evidence-based medicine to identify the best methodology for diagnosis and treatment of anterior pseudarthrosis. Methods The National Library of Medicine and Cochrane Database were queried using MeSH headings and key words relevant to pseudarthrosis and cervical spine surgery. Abstracts were reviewed, after which studies meeting inclusion criteria were selected. The guidelines group assembled an evidentiary table summarizing the quality of evidence (Classes I–III). Disagreements regarding the level of evidence were resolved through an expert consensus conference. The group formulated recommendations that contained the degree of strength based on the Scottish Intercollegiate Guidelines network. Validation was done through peer review by the Joint Guidelines Committee of the American Association of Neurological Surgeons/Congress of Neurological Surgeons. Results Evaluation for pseudarthrosis is warranted, as there may be an association between clinical outcome and pseudarthrosis. The strength of this association cannot be accurately determined because of the variable incidence of symptomatic and asymptomatic pseudarthroses (Class III). Revision of a symptomatic pseudarthrosis may be considered because arthrodesis is associated with improved clinical outcome (Class III). Both posterior and anterior approaches have proven successful for surgical correction of an anterior pseudarthrosis. Posterior approaches may be associated with higher fusion rates following repair of an anterior pseudarthrosis (Class III). Conclusions If suspected, pseudarthrosis should be investigated because there may be an association between arthrodesis and outcome. However, the strength of this association cannot be accurately determined. Anterior and posterior approaches have been successful.

Object The objective of this systematic review was to use evidence-based medicine to assess whether clinical factors predict surgical outcomes in patients undergoing cervical surgery. Methods The National Library of Medicine and Cochrane Database were queried using MeSH headings and keywords relevant to clinical preoperative factors. Abstracts were reviewed, and studies that met the inclusion criteria were selected. The guidelines group assembled an evidentiary table summarizing the quality of evidence (Classes I–III). Disagreements regarding the level of evidence were resolved through an expert consensus conference. The group formulated recommendations that contained the degree of strength based on the Scottish Intercollegiate Guidelines network. Validation was done through peer review by the Joint Guidelines Committee of the American Association of Neurological Surgeons/Congress of Neurological Surgeons. Results Preoperative sensory-evoked potentials may aid in providing prognostic information in selected patients in whom clinical factors do not provide clear guidance (Class II). Age, duration of symptoms, and preoperative neurological function may commonly affect outcome (Class III). Conclusions Age, duration of symptoms, and preoperative neurological function should be discussed with patients when surgical intervention for cervical spondylotic myelopathy is considered. Preoperative sensory-evoked potentials may be considered for patients in whom clinical factors do not provide clear guidance if such information would potentially change therapeutic decisions.

Object The objective of this systematic review was to use evidence-based medicine to compare the efficacy of different surgical techniques for the treatment of cervical spondylotic myelopathy (CSM). Methods The National Library of Medicine and Cochrane Database were queried using MeSH headings and keywords relevant to anterior and posterior cervical spine surgery and CSM. The guidelines group assembled an evidentiary table summarizing the quality of evidence (Classes I–III). The group formulated recommendations that contained the degree of strength based on the Scottish Intercollegiate Guidelines network. Validation was done through peer review by the Joint Guidelines Committee of the American Association of Neurological Surgeons/Congress of Neurological Surgeons. Results A variety of techniques have improved functional outcome after surgical treatment for CSM, including anterior cervical discectomy with fusion (ACDF), anterior cervical corpectomy with fusion (ACCF), laminoplasty, laminectomy, and laminectomy with fusion (Class III). Anterior cervical discectomy with fusion and ACCF appear to yield similar results in multilevel spine decompression for lesions at the disc level. The use of anterior plating allows for equivalent fusion rates between these techniques (Class III). If anterior fixation is not used, ACCF may provide a higher fusion rate than multilevel ACDF but also a higher graft failure rate than multilevel ACDF (Class III). Anterior cervical discectomy with fusion, ACCF, laminectomy, laminoplasty, and laminectomy with arthrodesis all provide near-term functional improvement for CSM. However, laminectomy is associated with late deterioration compared with the other types of anterior and posterior surgeries (Class III). Conclusions Multiple approaches exist with similar near-term improvements; however, laminectomy appears to have a late deterioration rate that may need to be considered when appropriate.

Object The objective of this systematic review was to use evidence-based medicine to examine the efficacy of cervical laminectomy for the treatment of cervical spondylotic myelopathy (CSM). Methods The National Library of Medicine and Cochrane Database were queried using MeSH headings and keywords relevant to cervical laminectomy and CSM. Abstracts were reviewed after which studies meeting inclusion criteria were selected. The guidelines group assembled an evidentiary table summarizing the quality of evidence (Classes I–III). Disagreements regarding the level of evidence were resolved through an expert consensus conference. The group formulated recommendations that contained the degree of strength based on the Scottish Intercollegiate Guidelines network. Validation was done through peer review by the Joint Guidelines Committee of the American Association of Neurological Surgeons/Congress of Neurological Surgeons. Results Laminectomy has improved functional outcome for symptomatic cervical myelopathy (Class III). The limitations of the technique are an increased risk of postoperative kyphosis compared to anterior techniques or laminoplasty or laminectomy with fusion (Class III). However, the development of kyphosis may not necessarily to diminish the clinical outcome (Class III). Conclusions Laminectomy is an acceptable therapy for near-term functional improvement of CSM (Class III). It is associated with development of kyphosis, however.

Background context The objective of the North American Spine Society (NASS) Evidence-Based Clinical Guideline on antithrombotic therapies in spine surgery was to provide evidence-based recommendations to address key clinical questions surrounding the use of antithrombotic therapies in spine surgery. The guideline is intended to address these questions based on the highest quality clinical literature available on this subject as of February 2008. The goal of the guideline recommendations was to assist in delivering optimum, efficacious treatment with the goal of preventing thromboembolic events. Purpose To provide an evidence-based, educational tool to assist spine surgeons in minimizing the risk of deep venous thrombosis (DVT) and pulmonary embolism (PE). Study design Systematic review and evidence-based clinical guideline. Methods This report is from the Antithrombotic Therapies Work Group of the NASS Evidence-Based Guideline Development Committee. The work group was composed of multidisciplinary spine care specialists, all of whom were trained in the principles of evidence-based analysis. Each member of the group was involved in formatting a series of clinical questions to be addressed by the group. The final questions agreed on by the group are the subject of this report. A literature search addressing each question and using a specific search protocol was performed on English language references found in MEDLINE, EMBASE (Drugs and Pharmacology), and four additional, evidence-based databases. The relevant literature was then independently rated by at least three reviewers using the NASS-adopted standardized levels of evidence. An evidentiary table was created for each of the questions. Final grades of recommendation for the answers to each clinical question were arrived at via Web casts among members of the work group using standardized grades of recommendation. When Level I to IV evidence was insufficient to support a recommendation to answer a specific clinical question, expert consensus was arrived at by the work group through the modified nominal group technique and is clearly identified as such in the guideline. Results Fourteen clinical questions were formulated, addressing issues of incidence of DVT and PE in spine surgery and recommendations regarding utilization of mechanical prophylaxis and chemoprophylaxis in spine surgery. The answers to these 14 clinical questions are summarized in this article. The respective recommendations were graded by the strength of the supporting literature that was stratified by levels of evidence. Conclusions A clinical guideline addressing the use of antithrombotic therapies in spine surgery has been created using the techniques of evidence-based medicine and using the best available evidence as a tool to assist spine surgeons in minimizing the risk of DVT and PE. The entire guideline document, including the evidentiary tables, suggestions for future research, and all references, is available electronically at the NASS Web site ( www.spine.org ) and will remain updated on a timely schedule.

Compression of the spinal cord by the degenerating cervical spine tends to lead to progressive clinical symptoms over a variable period of time. Surgical decompression can stop this process and lead to recovery of function. The choice of surgical technique depends on what is causing the compression of the spinal cord. This article reviews the symptoms and assessment for cervical spondylotic myelopathy (clinically evident compression of the spinal cord) and discusses the indications for decompression of the spinal cord anteriorly.

Background context Cervical spondylotic myelopathy has traditionally been managed through surgical decompression with or without reconstruction. Currently, a multicenter, blinded clinical trial that has supported such a therapeutic recommendation does not exist. There have been case-control studies that have and have not shown long-standing benefit to surgical decompression and reconstruction. Purpose The purpose of this review is to examine the efficacy of nonoperative therapy for cervical spondylotic myelopathy. Conclusions It appears that both static and dynamic factors play a role in the pathophysiology of cervical spondylotic myelopathy. Furthermore, once clinical cervical spondylotic myelopathy is evident, progression may occur despite the best of treatments, both surgical and nonsurgical.

The assessment of fusion status with static plain radiography is accurate in approximately two thirds of patients treated with lumbar fusion when the radiographic results are compared with surgical exploration findings. Therefore, static plain radiography is not recommended as a stand-alone modality following lumbar fusion procedures. The addition of lateral flexion-extension radiography may improve accuracy because the lack of motion between fused lumbar segments on lateral views is highly suggestive of a solid fusion. Some degree of motion between segments may be present even when the spine has fused. The amount of motion allowable across fused segments is not clear, and the role of internal fixation in limiting motion has also not been adequately addressed. The addition of multiplanar CT scanning results in the detection of pseudarthrosis in some patients in whom fusion has been deemed successful based on plain radiographic criteria. Therefore, CT scanning may be more accurate in the determination of fusion status than plain radiography; however, a rigorous comparison of modern CT scanning and surgical exploration has not been performed. It appears that RSA is exquisitely sensitive for the detection of motion between vertebral bodies, and the loss of motion between treated vertebral segments does appear to indicate the presence of fusion. The modality, however, is invasive and not widely available. Furthermore, the only

There have been a number of randomized studies supporting the use of ES for the promotion of bone healing following lumbar fusion. All of the published studies have methodological flaws that prevent the studies from providing Class I medical evidence. There is, however, Class II and III evidence to support the use of direct current stimulation or CCS for enhancing fusion rates in high-risk patients undergoing lumbar PLF. A beneficial effect on fusion rates in patients not at "high risk" has not been convincingly demonstrated, nor has an effect been shown for these modalities in patients treated with interbody fusion. There is limited evidence both for and against the use of PEMFS for enhancing fusion rates following PLE Class II and III medical evidence supports the use of PEMFS for promoting arthrodesis following interbody fusion. Although some studies have purported to demonstrate functional improvement in some patient subgroups, other studies have not detected differences. All of the reviewed studies are significantly flawed by the use of a four-point patient satisfaction scale as the primary outcome measure. This outcome measure is not validated. Because of the use of this flawed outcome measure and because of the conflicting results reported in the better-designed studies that assess functional outcome, there is no consistent medical evidence to support or refute use of these devices for improving patient outcomes.

Discography is an exquisitely sensitive but not specific diagnostic test for the diagnosis of discogenic low-back pain. The restriction of the definition of a positive discographic study to one that elicits concordant pain from a morphologically abnormal disc improves the definition's accuracy. Fusion surgery based on discography alone, however, is not reliably associated with clinical success. Therefore, discography is not recommended as a standalone test for treatment decisions in patients with low-back pain. Magnetic resonance imaging is a sensitive and noninvasive test for the presence of degenerative disc disease. Discography should not be attempted in patients with normal lumbar MR images. Discography appears to have a role in the evaluation of patients with low-back pain, but it is best limited to the evaluation of abnormal interspaces identified on MR imaging, the investigation of adjacent-level disc disease, and as a means to rule out cases of nonorganic pain from surgical consideration.

Based on the medical evidence derived from the scientific literature on this topic, there does not appear to be evidence to support the hypothesis that fusion (with or without instrumentation) provides any benefit over decompression alone in the treatment of lumbar stenosis in patients in whom there is no evidence of preoperative deformity or instability. A single report provides Class II medical evidence and several papers provide Class III medical evidence suggesting that the addition of fusion to decompression in patients with lumbar stenosis and instability evidenced by movement on preoperative flexion-extension radiographs does improve outcome. There are also reports (Class III medical evidence) indicating that patients with lumbar stenosis, without deformity or instability, treated with wide decompression or facetectomy may suffer iatrogenic lumbar instability. Fusion in these patients may improve outcome. There is conflicting Class III medical evidence regarding the application of instrumentation in addition to PLF in patients treated for lumbar stenosis without deformity or preoperative instability.