Systematic review.Clinical questions: (1) What evidence is available from studies of cervical total disc arthroplasty (C-ADR) failure and retrieval regarding durability, wear, and reasons for failure of C-ADR? (2) What evidence is available from experimental models regarding the durability of C-ADR beyond 5 years? We searched electronic databases to identify published reports of explanted cervical artificial discs and biomechanical simulations of disc wear. Nine articles were identified describing 17 devices explanted from human patients and four articles describing 23 devices explanted from non-human subjects. Wear properties were not consistently reported across studies, so summaries for specific variables are based on few cases. No device had been implanted longer than 4 years. In both human and non-human subjects, devices showed evidence of metallic and polymeric (for discs with polymer components) debris. Inflammatory cells were frequently present in surrounding soft tissues. Signs of infection were uncommon.Four patients had reactions interpreted as hypersensitivity to metal. We identified three articles on biomechanical wear simulations. Devices were tested between 10 and 20 million cycles in axial loading, flexion/extension, and lateral bending. No device failures were reported. One study suggests such simulations may represent 50 or more years of wear in actual patients. Cervical disc implants consistently produced polymeric and metallic debris, which was typically accompanied by inflammation. Hypersensitivity to metal may increase risk for device failure. Biomechanical simulations indicate that cervical disc implants may be durable beyond the currently reported length of clinical follow-up.
Study Design Clinical practice guideline development following the GRADE process. Objectives Hemodynamic management is one of the only available treatment options that likely improves neurologic outcomes in patients with acute traumatic spinal cord injury (SCI). Augmenting mean arterial pressure (MAP) aims to improve blood perfusion and oxygen delivery to the injured spinal cord in order to minimize secondary ischemic damage to neural tissue. The objective of this guideline was to update the 2013 AANS/CNS recommendations on the hemodynamic management of patients with acute traumatic SCI, acknowledging that much has been published in this area since its publication. Specifically, we sought to make recommendations on 1. The range of mean arterial pressure (MAP) to be maintained by identifying an upper and lower MAP limit; 2. The duration of such MAP augmentation; and 3. The choice of vasopressor. Additionally, we sought to make a recommendation on spinal cord perfusion pressure (SCPP) targets. Methods A multidisciplinary guideline development group (GDG) was formed that included health care professionals from a wide range of clinical specialities, patient advocates, and individuals living with SCI. The GDG reviewed the 2013 AANS/CNS guidelines and voted on whether each recommendation should be endorsed or updated. A systematic review of the literature, following PRISMA standards and registered in PROSPERO, was conducted to inform the guideline development process and address the following key questions: (i) what are the effects of goal-directed interventions to optimize spinal cord perfusion on extent of neurological recovery and rates of adverse events at any time point of follow-up? and (ii) what are the effects of particular monitoring techniques, perfusion ranges, pharmacological agents, and durations of treatment on extent of neurological recovery and rates of adverse events at any time point of follow-up? The GDG combined the information from this systematic review with their clinical expertise in order to develop recommendations on a MAP target range (specifically an upper and lower limit to target), the optimal duration for MAP augmentation, and the use of vasopressors or inotropes. Using methods outlined by the GRADE working group, recommendations were formulated that considered the balance of benefits and harms, financial impact, acceptability, feasibility and patient preferences. Results The GDG suggested that MAP should be augmented to at least 75-80 mmHg as the “lower limit,” but not actively augmented beyond an “upper limit” of 90-95 mmHg in order to optimize spinal cord perfusion in acute traumatic SCI. The quality of the evidence around the “target MAP” was very low, and thus the strength of this recommendation is weak. For duration of hemodynamic management, the GDG “suggested” that MAP be augmented for a duration of 3-7 days. Again, the quality of the evidence around the duration of MAP support was very low, and thus the strength of this recommendation is also weak. The GDG felt that a recommendation on the choice of vasopressor or the use of SCPP targets was not warranted, given the dearth of available evidence. Conclusion We provide new recommendations for blood pressure management after acute SCI that acknowledge the limitations of the current evidence on the relationship between MAP and neurologic recovery. It was felt that the low quality of existing evidence and uncertainty around the relationship between MAP and neurologic recovery justified a greater range of MAP to target, and for a broader range of days post-injury than recommended in previous guidelines. While important knowledge gaps still remain regarding hemodynamic management, these recommendations represent current perspectives on the role of MAP augmentation for acute SCI.
Objectives To develop a framework for understanding the evidence needs of health systems to inform the AHRQ EPC Program future efforts. Data sources Three data sources were used: (a) peer-reviewed literature from a systematic search of English-language publications in MEDLINE from January 2007–April 2017, (b) original data from four programs serving health system requests for evidence syntheses, and (c) input during a face-to-face meeting at AHRQ in June 2017 from health system stakeholders and EPC investigators. Methods Data were synthesized narratively and thematically. We developed an initial framework to guide discussion and qualitative analysis. We built consensus around themes and refinement of the framework through weekly phone conferences, electronic communications, and a face-to-face meeting of workgroup members and health systems experts. Results From the literature review, we found that health systems seek evidence to inform decisions about acquiring new or emerging medical technologies; implementation or expansion of service offerings; and selection of governance, finance or delivery system models. Studies emphasize a preference for rapidly completed, succinct and easily understood evidence syntheses with layered information presentations. Studies of tools for promoting health system use of evidence describe methods for clarifying how the evidence applies to the local and operational context and how evidence intersects with other considerations in decisionmaking. Data from the four evidence synthesis programs illustrate a breadth of questions addressed and report types used by health systems. Discussions with health system experts highlighted the importance of trustworthiness of the process for synthesizing published literature; trustworthiness of the evidence itself; mechanisms for integrating internally generated data with evidence from published literature; and evaluation, feedback and updating mechanisms facilitated by transforming the published literature into machine executable knowledge for use by decisionmakers. Conclusions We identified several domains to facilitate interaction between health systems and evidence synthesis producers. Successful engagement will require specifying the type of decision or question of the health system; type of evidence synthesis to best address the question(s) of interest; tools to promote the use of evidence; and a feedback or auditing mechanism to determine the impact of evidence integration into health system decisions. Both the trustworthiness of the evidence synthesis process and communication of the trustworthiness of the evidence are additional key domains. Partnerships with health systems are critical for understanding their evidence needs and establishing trust.
Systematic review.To determine whether various preoperative factors affect patient outcome after cervical laminoplasty for cervical spondylotic myelopathy (CSM) and/or ossification of posterior longitudinal ligament (OPLL).Cervical laminoplasty is a procedure designed to decompress the spinal cord by enlarging the spinal canal while preserving the lamina. Prior research has identified a variety of potential predictive factors that might affect outcomes after this procedure.A systematic search of multiple major medical reference databases was conducted to identify studies explicitly designed to evaluate the effect of preoperative factors on patient outcome after cervical laminoplasty for CSM or OPLL. Studies specifically designed to evaluate potential predictive factors and their associations with outcome were included. Only cohort studies that used multivariate analysis, enrolled at least 20 patients, and adjusted for age as a potential confounding variable were included. JOA (Japanese Orthopaedic Association), modified JOA, and JOACMEQ-L (JOA Cervical Myelopathy Evaluation Questionnaire lower extremity function section) scores were the main outcome measures. Clinical recommendations and consensus statements were made through a modified Delphi approach by applying the GRADE (Grading of Recommendation Assessment, Development and Evaluation)/AHRQ (Agency for Healthcare Research and Quality) criteria.The search strategy yielded 433 citations, of which 1 prospective and 11 retrospective cohort studies met our inclusion criteria. Overall, the strength of evidence from the 12 studies is low or insufficient for most of the predictive factors. Increased age was not associated with poorer JOA outcomes for patients with CSM, but there is insufficient evidence to make a conclusion for patients with OPLL. Increased severity of disease and a longer duration of symptoms might be associated with JOA outcomes for patients with CSM. Hill-shaped lesions might be associated with poorer JOA outcomes for patients with OPLL. There is insufficient evidence to permit conclusions regarding other predictive factors.Overall, the strength of evidence for all of the predictive factors was insufficient or low. Given that cervical myelopathy due to CSM tends to be progressive and that increased severity of myelopathy and duration of symptoms might be associated with poorer outcomes after cervical laminoplasty for CSM, it is preferable to perform laminoplasty in patients with CSM earlier rather than waiting for symptoms to get worse. Further research is needed to more clearly identify predictive factors that affect outcomes after cervical laminoplasty because there were relatively few studies identified that used multivariate analyses to control for confounding factors and many of these studies did not provide a detailed description of the multivariate analyses or the magnitude of effect estimates. EVIDENCE-BASED CLINICAL RECOMMENDATIONS:For patients with CSM, increased age is not a strong predictor of clinical neurological outcomes after laminoplasty; therefore, age by itself should not preclude cervical laminoplasty for CSM.Low.Strong.For patients with CSM, increased severity of disease and a longer duration of symptoms might be associated with poorer clinical neurological outcomes after laminoplasty; therefore, we recommend that patients be informed about this.Low.Strong. SUMMARY STATEMENTS: For patients with OPLL, hill-shaped lesions might be associated with poorer clinical neurological outcomes after laminoplasty; therefore, surgeons might consider potential benefits and risks of alternative or additional surgery.
Objectives To evaluate the effectiveness and comparative effectiveness of opioid, nonopioid pharmacologic, and nonpharmacologic therapy in patients with specific types of acute pain, including effects on pain, function, quality of life, adverse events, and long-term use of opioids. Data sources Electronic databases (Ovid® MEDLINE®, PsycINFO®, Embase®, the Cochrane Central Register of Controlled Trials, and the Cochrane Database of Systematic Reviews) to August 2020, reference lists, and a Federal Register notice. Review methods Using predefined criteria and dual review, we selected randomized controlled trials (RCTs) of outpatient therapies for eight acute pain conditions: low back pain, neck pain, other musculoskeletal pain, neuropathic pain, postoperative pain following discharge, dental pain (surgical or nonsurgical), pain due to kidney stones, and pain due to sickle cell disease. Meta-analyses were conducted on pharmacologic therapy for dental pain and kidney stone pain, and likelihood of repeat or rescue medication use and adverse events. The magnitude of effects was classified as small, moderate, or large using previously defined criteria, and strength of evidence was assessed. Results One hundred eighty-three RCTs on the comparative effectiveness of therapies for acute pain were included. Opioid therapy was probably less effective than nonsteroidal anti-inflammatory drugs (NSAIDs) for surgical dental pain and kidney stones, and might be similarly effective as NSAIDs for low back pain. Opioids and NSAIDs were more effective than acetaminophen for surgical dental pain, but opioids were less effective than acetaminophen for kidney stone pain. For postoperative pain, opioids were associated with increased likelihood of repeat or rescue analgesic use, but effects on pain intensity were inconsistent. Being prescribed an opioid for acute low back pain or postoperative pain was associated with increased likelihood of use of opioids at long-term followup versus not being prescribed, based on observational studies. Heat therapy was probably effective for acute low back pain, spinal manipulation might be effective for acute back pain with radiculopathy, acupressure might be effective for acute musculoskeletal pain, an opioid might be effective for acute neuropathic pain, massage might be effective for some types of postoperative pain, and a cervical collar or exercise might be effective for acute neck pain with radiculopathy. Most studies had methodological limitations. Effect sizes were primarily small to moderate for pain, the most commonly evaluated outcome. Opioids were associated with increased risk of short-term adverse events versus NSAIDs or acetaminophen, including any adverse event, nausea, dizziness, and somnolence. Serious adverse events were uncommon for all interventions, but studies were not designed to assess risk of overdose, opioid use disorder, or long-term harms. Evidence on how benefits or harms varied in subgroups was lacking. Conclusions Opioid therapy was associated with decreased or similar effectiveness as an NSAID for some acute pain conditions, but with increased risk of short-term adverse events. Evidence on nonpharmacological therapies was limited, but heat therapy, spinal manipulation, massage, acupuncture, acupressure, a cervical collar, and exercise were effective for specific acute pain conditions. Research is needed to determine the comparative effectiveness of therapies for sickle cell pain, acute neuropathic pain, neck pain, and management of postoperative pain following discharge; effects of therapies for acute pain on non-pain outcomes; effects of therapies on long-term outcomes, including long-term opioid use; and how benefits and harms of therapies vary in subgroups.
Study Design Mixed-methods approach. Objectives Intra-operative spinal cord injury (ISCI) is a devastating complication of spinal surgery. Presently, a uniform definition for ISCI does not exist. Consequently, the reported frequency of ISCI and important risk factors vary in the existing literature. To address these gaps in knowledge, a mixed-methods knowledge synthesis was undertaken. Methods A scoping review was conducted to review the definitions used for ISCI and to ascertain the frequency of ISCI. The definition of ISCI underwent formal review, revision and voting by the Guidelines Development Group (GDG). A systematic review of the literature was conducted to determine the risk factors for ISCI. Based on this systematic review and GDG input, a table was created to summarize the factors deemed to increase the risk for ISCI. All reviews were done according to PRISMA standards and were registered on PROSPERO. Results The frequency of ISCI ranged from 0 to 61%. Older age, male sex, cardiovascular disease including hypertension, severe myelopathy, blood loss, requirement for osteotomy, coronal deformity angular ratio, and curve magnitude were associated with an increased risk of ISCI. Better pre-operative neurological status and use of intra-operative neuromonitoring (IONM) were associated with a decreased risk of ISCI. The risk factors for ISCI included a rigid thoracic curve with high deformity angular ratio, revision congenital deformity with significant cord compression and myelopathy, extrinsic intradural or extradural lesions with cord compression and myelopathy, intramedullary spinal cord tumor, unstable spine fractures (bilateral facet dislocation and disc herniation), extension distraction injury with ankylosing spondylitis, ossification of posterior longitudinal ligament (OPLL) with severe cord compression, and moderate to severe myelopathy. Conclusions ISCI has been defined as “a new or worsening neurological deficit attributable to spinal cord dysfunction during spine surgery that is diagnosed intra-operatively via neurophysiologic monitoring or by an intraoperative wake-up test, or immediately post-operatively based on clinical assessment”. This paper defines clinical and imaging factors which increase the risk for ISCI and that could assist clinicians in decision making.
What is in a word? Degenerative disc disease—a disease or a focal syndrome? A semantic exploration of spinal terminology and its inferences to current concepts and our practice. This focus issue is entirely devoted to symptomatic or imaging-based findings that occur at a segment adjacent to a previously operated spinal motion segment. Already 60 years ago, the finding of “adjacent segment disease” (ASD) was reported in case reports as a relatively unusual complication of lumbar or lumbosacral fusions.1,2 There are, however, still today a number of unanswered questions regarding what has become frequently referred to as “ASD.” What we do know is that what was originally thought to be rare is now considered a potential complication of all spine surgery, particularly arthrodesis. Despite an increasing body of literature, there are many unanswered questions, as follows, related to this topic. Are the findings due to iatrogenic processes or are they due to the natural history? If iatrogenic, can we modify our interventions to decrease its incidence? How should we study and interpret what occurs at motion segments adjacent to an operated spinal motion segment? To what extent do imaging findings correlate with clinical symptoms and when is treatment necessary? How do we treat adjacent segment pathology (ASP)? We think that these questions are especially timely for a variety of reasons. As spine specialists, we are increasingly held responsible for the results of our interventions. Are changes that occur in spinal motion segments outside our treatment target zone an expression of underlying patient aging or disease, or are our treatment modalities creating a degenerative ripple effect that affects through previously unaffected motion segments of the human spinal column? Are there things we can do to minimize or even avoid this risk, or at least predict it with some degree of certainty? Are newer intervention strategies, such as motion-preserving devices, capable of decreasing ASDs? As we raise these questions, the basic conceptual conflict of disc degeneration remains unsettled: Is this process in fact a “disease,” an abnormal condition that affects the body of an organism, for which our interventions simply cannot offer a systemic answer but rather provide a focal temporary remedy?3 Or are we dealing with a focal syndrome, an “association of several clinically recognizable features,” signs (observed by someone other than the patient), symptoms (reported by the patient), phenomena, or characteristics that often occur together, so that the presence of 1 or more features alerts the health care provider to the possible presence of the others, for the creation of which we may contribute depending on the type of treatment we choose?3 TERMINOLOGY “What's in a name? That which we call a rose by any other name would smell as sweet.” —Juliet Capulet from Romeo & Juliet by William Shakespeare As our work progressed, it became obvious to us that a major problem with research on this topic had to do with the lack of uniform terminology. Although a rose by any other name may still be a rose, Shakespeare never had to do a literature search to find all the articles written about roses. If he had, he would have wished for a single term to look up, as we did for this focus issue. Little did we know when we started this project that one of our greatest challenges would turn out to be the lack of uniformity in the nomenclature of the pathological findings that develop at a segment adjacent to a previously operated segment. Such findings go by many names in the literature, including: adjacent segment degeneration, disease, deformity, fracture, adjacent level ossification development, and proximal junctional kyphosis. Substitute the words “proximal/distal junctional or superjacent/subjacent” for the words adjacent segment and there are another group of words that can be used to describe these findings. The nomenclature lacks standardization, making it difficult to do a comprehensive search and understand exactly what the authors mean. Lack of standardized terminology also leads to confusion for clinicians, patients, payers, and others. Imprecision in definitions results in imprecision in classification and analysis. For this reason, we have proposed a simple, descriptive terminology: ASP as the general term to describe changes that occur adjacent to a previously operated level. Under this heading, “radiographical ASP” (RASP) refers to radiographical changes that occur at the adjacent segment. Strictly speaking, RASP would exclude magnetic resonance images (MRIs), because an MRI is not a radiograph. However, in the modern era, the terms “radiology, radiograph, and radiologist” have taken on a more expanded connotation. Hence, a radiologist does not only interpret radiographs but also MRIs and ultrasonographs. Similarly, MRIs and ultrasonographs are considered “radiological” modalities that a “radiology” department offers. We think that RASP would be understood to refer to all imaging modality changes. “Clinical ASP” (CASP) refers to clinical symptoms and signs that occur at the adjacent segment, which almost always are associated with RASP. Why not simply keep some of the terms already utilized such as “adjacent level degeneration or disease?” Because these terms have ambiguous definitions and are incomplete representations of multifactorial processes, which may involve some or several if not all components of a motion segment, or the vertebral body itself or the accompanying neural elements. To continue the use of previously used terms utilized interchangeably in past publications would have meant to simply continue the confusion. Hence ASP, RASP, and CASP provide clear, encompassing, and unencumbered new operative concepts, which allow us to hopefully move forward. The new approach to terminology will finally also provide a rational start to categorizing findings that can be used to create a logical classification system. MATERIALS AND METHODS The methods for each systematic review in this focus issue are described in detail in a separate article.4 Briefly, we invited nearly 30 expert spine surgeons, neurosurgeons, and epidemiologists to participate in this focus issue. We sought to answer nearly 40 clinical questions surrounding ASP, which are addressed in the 14 articles that make up this Focus Issue. IMPLICATIONS It is important for the reader to understand that the majority of the clinical questions addressed in this Spine focus issue explore the risks “of” and risk factors associated “with” a single entity: ASP. ASP could be one of the major factors in reoperations of patients who have received fusions. Avoidance of reoperations is an emerging battleground in the quest to reduce health care spending and improve patient safety and quality of life. Simplistic prevention efforts of ASP, such as simply fusing more levels during the index procedure at the cost of increased upfront patient morbidity and other invasiveness-related outcomes are simply not acceptable or realistic propositions. The ultimate surgical cure for ASP would be a fusion from the occiput to the sacrum—obviously not advisable for the vast majority of patients. Acceptance of some ASPs may be a necessity, especially in the very young or the very elderly patient with multilevel radiographical pathology, where a single symptomatic level procedure may be indicated. It is not the intent of this supplement to establish patient care guidelines. Such guidelines are traditionally developed after a systematic evaluation of treatment safety and efficacy, and finally culminate in strong or weak recommendations. Guideline development requires an evaluation of the therapeutic benefits and harms of a given treatment and consideration of economic implications. Similarly, functional outcomes and other complications were not assessed in this project. Hence, the consensus statements and clinical recommendations made in this focus issue are not designed to recommend one treatment or another but rather to inform both the surgeon and the patient about the potential risk for ASP as well as considerations for how they might minimize this risk. We think that this information may be helpful in the consenting and shared decision-making process in the future because ASP data have generally not been available in studies comparing treatments. To date, formal evidence-based assessment groups such as the GRADE (Grading of Recommendations Assessment, Development and Evaluation) working group has not provided formal guidance regarding the application of the GRADE system to questions on prognosis or risk factor evaluation or recommendations about these. According to their website (http://www.gradeworkinggroup.org/), “The GRADE Working Group began in the year 2000 as an informal collaboration of people with an interest in addressing the shortcomings of present grading systems in health care. The working group has developed a common, sensible and transparent approach to grading quality of evidence and strength of recommendations.” The GRADE perspectives on the implications of a “strong” recommendation are given further with general considerations for studies of prognosis that were thought to be logical for this supplement: Patients: Most people in this situation would want the recommended course of action and only a small proportion would not. Considerations for risk/prognosis: Most people would find the risk acceptable when weighed against the benefits and costs. The assumption is that both benefits and risks are discussed with patients as part of shared decision making. Clinicians: Most patients should receive the recommended course of action. Considerations for risk/prognosis: Most clinicians are comfortable with the risks when weighed with the benefits and cost. Policy makers: The recommendation can be adapted as a policy in most situations. Considerations for risk/prognosis: The risks should not preclude policy adoption based on demonstrated benefits and reasonable cost. These considerations have not been evaluated beyond this supplement, but seem logical given the subject matter. Finally, for the majority of the topics in this issue, there was a dearth of high-quality articles that could be used to answer the clinically important questions that the expert panels raised. Not surprisingly, our investigators noted that further investigation was necessary. However, we hoped to increase awareness of factors and circumstances surrounding ASP and provide constructive insights into future investigations. It is our sincere hope that the readership uses this focus issue as a launching point for further investigations on this very important topic. The 14 article titles, their key clinical questions, and their respective consensus statements or clinical recommendations can be found in the Table 1 of this article.TABLE 1-a: Article Title, Clinical Questions, Clinical Recommendations, and Summary Statements for the Spine Focus Issue on ASPTABLE 1-b: Article Title, Clinical Questions, Clinical Recommendations, and Summary Statements for the Spine Focus Issue on ASPTABLE 1-c: Article Title, Clinical Questions, Clinical Recommendations, and Summary Statements for the Spine Focus Issue on ASPTABLE 1-d: Article Title, Clinical Questions, Clinical Recommendations, and Summary Statements for the Spine Focus Issue on ASPTABLE 1-e: Article Title, Clinical Questions, Clinical Recommendations, and Summary Statements for the Spine Focus Issue on ASPCONCLUSION Not surprisingly, the hope to find simple answers for causes of ASP or potential prevention strategies proved futile. We have not been able to conclusively answer the question as to whether ASP is a natural degenerative process or an iatrogenic one, which one can delay with an ideal operation. Although no amount of meticulous attention to detail is likely to prevent it, it is hoped that it may be possible to delay it by reducing the mechanical forces acting on the adjacent segment and maximizing normal kinematics as much as possible. We hope to have helped the field by providing a more standardized nomenclature with the new acronyms “ASP,” “RASP,” and “CASP.” Clarification of the operational words we choose to describe what we see, treat, and investigate in the spinal motion segments surrounding our primary target levels will over time hopefully result in tangible improvements to our patients, spine clinicians, and researchers. Beyond this, a formal approach to categorizing the severity of ASP through systematic and validated severity scales remains an achievable next step.
Study Design: Systematic review. Objective: To conduct a systematic review and synthesis of the literature to assess the comparative effectiveness, safety, and cost-effectiveness of early (≤24 hours) versus late decompression (>24 hours) in adults with acute spinal cord injury (SCI). Methods: A systematic search was conducted of Medline, EMBASE, the Cochrane Collaboration Library, and Google Scholar to identify studies published through November 6, 2014. Studies published in any language, in humans, and with an abstract were considered for inclusion. Included studies were critically appraised and the overall strength of evidence was determined using methods proposed by the Grading of Recommendation Assessment, Development and Evaluation working group. Results: The search yielded 449 potentially relevant citations. Sixteen additional primary studies were identified through other sources. Six studies met inclusion criteria. All but 2 studies were considered to have moderately high risk of bias. Across studies and injury levels, the impact of early surgical decompression (≤24 hours) on clinically important improvement in neurological status was variable. Isolated studies reported statistically significant and clinically important improvements at 6 months (cervical injury, low strength of evidence) and following discharge from inpatient rehabilitation (all levels, very low strength of evidence) but not at other time points; another study observed a statistically significant 6 point improvement in ASIA Impairment Scale (AIS) among patients with AIS B, C, or D, but not for those with AIS A (very low strength of evidence). In one study of acute central cord syndrome without instability, a clinically and statistically meaningful improvement in total motor scores was reported at 6 and 12 months in patients treated early (versus late). There were, however, no significant differences in AIS improvement between early and late surgical groups at 6- or 12-months (very low strength of evidence). One of 3 studies found a shorter length of hospital stay associated with early surgical decompression. Of 3 studies reporting on safety, no significant differences in rates of complications (including mortality, neurologic deterioration, pneumonia or pressure ulcers) were noted between early and late decompression groups. Conclusions: Results surrounding the efficacy of early versus late decompressive surgery, as well as the quality of evidence available, were variable depending on the level of SCI, timing of follow-up, and specific outcome considered. Existing evidence supports improved neurological recovery among cervical SCI patients undergoing early surgery; however, evidence regarding remaining SCI populations and clinical outcomes was inconsistent.
In Brief Study Design. Systematic review. Objective. To assess whether the presence or magnitude of postsurgical malalignment in the coronal (scoliosis) or sagittal plane (kyphosis/spondylolisthesis) affects the risk of cervical adjacent segment pathology (ASP). Summary of Background Data. ASP occurs in selected patients who have undergone surgical treatment for cervical spondylosis. The reasons are multifactorial; however, postsurgical alignment may play a key role. To elucidate this issue, a systematic review of the literature was undertaken. Methods. A systematic search in PubMed was conducted for literature published in English language through February 15, 2012. Studies in adults, designed to evaluate postsurgical sagittal or coronal malalignment as risk factors for radiographical or clinical ASP, were sought. Studies of pediatric or oncological patients were excluded. Case reports, case series, and patient populations of less than 10 patients were also excluded. Unadjusted risk ratios (RRs) and 95% confidence intervals were calculated to evaluate the association between alignment and the risk for developing ASP. Results. The search yielded 338 citations. Of that, 311 were excluded at the title and abstract level. Of the 27 selected for full-text review, 5 poor-quality retrospective studies met the inclusion criteria and described sagittal imbalance measures as risk factors for radiological ASP after anterior surgery. No studies examined ASP after posterior cervical surgery. Three studies provided data from which unadjusted RRs and 95% confidence intervals could be calculated. These studies showed an increased risk of ASP associated with malalignment (RR, 2.24 [95% confidence interval, 1.40–3.56]; RR, 2.40 [1.33, 4.33]; RR, 1.32 [0.96, 1.81]). No study evaluating coronal imbalance as a risk factor for cervical ASP was found and none reported on clinical ASP. Conclusion. There is low-grade evidence from 3 published studies that postsurgical sagittal imbalance may increase the risk for cervical radiological ASP. Consensus Statement An attempt should be made to maintain or restore cervical lordosis in surgical intervention for cervical disorders. Strength of Statement: Weak Surgery for symptomatic cervical spondylosis may be complicated by adjacent segment pathology (ASP). A systematic review of the literature demonstrated an association between sagittal malalignment and ASP (low grade of evidence). On the basis of this, we recommend that anatomical alignment be maintained or restored whenever possible when undertaking the surgical treatment of cervical disorders.
