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Guideline Summary
Guideline Title
Clinical prognostic indicators of surgical outcome in cervical spondylotic myelopathy.
Bibliographic Source(s)
Holly LT, Matz PG, Anderson PA, Groff MW, Heary RF, Kaiser MG, Mummaneni PV, Ryken TC, Choudhri TF, Vresilovic EJ, Resnick DK, Joint Section on Disorders of the Spine and Peripheral Nerves [trunc]. Clinical prognostic indicators of surgical outcome in cervical spondylotic myelopathy. J Neurosurg Spine. 2009 Aug;11(2):112-8. [19 references] PubMed External Web Site Policy
Guideline Status

This is the current release of the guideline.

Scope

Disease/Condition(s)

Cervical spondylotic myelopathy

Guideline Category
Counseling
Evaluation
Clinical Specialty
Chiropractic
Family Practice
Geriatrics
Internal Medicine
Neurological Surgery
Neurology
Orthopedic Surgery
Physical Medicine and Rehabilitation
Preventive Medicine
Sports Medicine
Intended Users
Physicians
Guideline Objective(s)
  • To address questions regarding the therapy, diagnosis, and prognosis of cervical degenerative disease using an evidence-based approach
  • To evaluate the ability of clinical prognostic factors to predict surgical outcomes in cervical spondylotic myelopathy (CSM)
Target Population

Patients with cervical spondylotic myelopathy

Interventions and Practices Considered
  1. Evaluation of preoperative somatosensory-evoked potentials (SEPs)
  2. Consideration of clinical prognostic factors and discussion with patients before surgical intervention
    • Age
    • Duration of symptoms
    • Preoperative neurological function
Major Outcomes Considered
  • Sensitivity and predictive value of sensory-evoked potentials for surgical outcome
  • Predictive value of patient age, duration and symptoms, and preoperative neurological function for surgical outcome
  • Neurological recovery rate using modified Japanese Orthopaedic Association (mJOA) scale as a functional outcome

Methodology

Methods Used to Collect/Select the Evidence
Hand-searches of Published Literature (Secondary Sources)
Searches of Electronic Databases
Description of Methods Used to Collect/Select the Evidence

Search Criteria

The expert group performed a computerized search of the Cochrane Database and the National Library of Medicine Database of the literature published between 1966 and 2007 using keywords and MeSH headings. A search using the subject heading "cervical spondylotic myelopathy" yielded 684 citations. A search using the headings "cervical spondylotic myelopathy and outcomes" provided 49 citations. The expert group evaluated the abstracts and titles of the aforementioned citations and selected articles for review that focused on predictive clinical factors for outcome after surgery for cervical spondylotic myelopathy (CSM). The group chose additional manuscripts from the reference lists of the selected articles. Among the articles reviewed, the expert group found 14 that examined treatment of CSM and clinical prognostic factors (see Table 1 in the original guideline document).

Number of Source Documents

14 articles were included in the evidentiary table.

Methods Used to Assess the Quality and Strength of the Evidence
Expert Consensus
Weighting According to a Rating Scheme (Scheme Given)
Rating Scheme for the Strength of the Evidence

Strength of the Evidence

Class I: Evidence evolved from well-designed randomized controlled trials (RCTs).

Class II: Evidence arose from RCTs with design problems or from well-designed cohort studies.

Class III: Evidence arose from case series or poorly designed cohort studies.

Methods Used to Analyze the Evidence
Systematic Review with Evidence Tables
Description of the Methods Used to Analyze the Evidence

Quality of Evidence

The guidelines group assembled an evidentiary table summarizing the quality of evidence.

The mainstay of any evidence-based review lies in the assessment of the quality of strength of the data. The group assessed the methodology of each manuscript carefully and assessed each study according to its relevant category—diagnosis, therapy, prognosis, or harm. The group applied a weighting scheme according to the methods delineated by Sackett and colleagues. After review of the study methods, the group determined how well each individual study met the validity requirements within its category and assigned a class to the study. In keeping with prior surgical guidelines, a 3-class system (Classes I, II, and III) was used (see the "Rating Scheme for the Strength of the Evidence" field).

It was the group's conclusion that expert opinion and case reports did not add significantly to the evidence used for the formulation of recommendations and should not be separately classified.

When disagreement arose as to the strength of evidence (that is, determining how well the methods conformed to the weighting scheme), the group resolved said disagreement by expert consensus within itself. To avoid the undue influence of a single individual, each member had the opportunity to list the reason(s) why a study should be downgraded or upgraded. Group members then prioritized each reason. If a reason had low priority, it was eliminated. Ultimately, there was convergence of opinion within the group. The result was unanimity to support publicly the assessment of the quality of evidence and the strength of the guidelines despite potential individual reservations regarding specific details.

Methods Used to Formulate the Recommendations
Expert Consensus (Consensus Development Conference)
Description of Methods Used to Formulate the Recommendations

In March 2006, the Joint Section on Disorders of the Spine and Peripheral Nerves of the American Association of Neurological Surgeons/Congress of Neurological Surgeons compiled an expert group to perform an evidence-based review of the clinical literature on the management of cervical degenerative spine disease. Comprising the group were spinal neurosurgeons and orthopedic surgeons active in the Joint Section and/or the North American Spine Society. This combination of specialties ensured the comprehensive participation of both surgical specialties. At least half of the group had participated in prior guidelines development, and several had completed the evidence-based course developed by the North American Spine Society. The multiple recommendations represent the product of this group with input from the Guidelines Committee of the American Association of Neurological Surgeons/Congress of Neurological Surgeons.

Formulation and Strength of Recommendations

The group formulated recommendations using expert consensus in a consensus development conference. After assessment of the quality and strength of evidence, the assigned subgroup summarized the studies leading to the basis of the Scientific Foundation section of each chapter. In general, if high-quality (Class I or II) data were available on a particular topic, poorer quality evidence was only briefly summarized. If no high-quality evidence existed, Class III data formed the basis of the scientific foundation. Based on the quality and strength of data, each subgroup formulated initial treatment recommendations. Each subgroup presented these to the entire group whose membership included active members of the Congress of Neurological Surgeons, the American Association of Neurological Surgeons, the North American Spine Society, and the American Academy of Orthopedic Surgery. The presentation was a plenary session acting as a consensus development conference from which final recommendations arose.

The group gave each recommendation a grade for strength based on the quality of the underlying studies. Grading was based on the methods of the Scottish Intercollegiate Guidelines Network and also mirrored that used by the Oxford Centre for Evidence-Based Medicine (www.cebm.net External Web Site Policy) (see the "Rating Scheme for the Strength of the Recommendations" field).

Rating Scheme for the Strength of the Recommendations

Strength of the Recommendations

Grade A: Recommendations based on consistent Class I studies.

Grade B: Recommendations based on a single Class I study or consistent Class II studies.

Grade C: Recommendations based on a single Class II study.

Grade D: Recommendations based on Class III or weaker data, or based on inconsistent data.

Cost Analysis

A formal cost analysis was not performed and published cost analyses were not reviewed.

Method of Guideline Validation
External Peer Review
Internal Peer Review
Description of Method of Guideline Validation

Validation was done through peer review by the Joint Guidelines Committee of the American Association of Neurological Surgeons/Congress of Neurological Surgeons and through external peer review prior to publication.

Recommendations

Major Recommendations

The rating schemes used for the strength of the evidence (Class I-III) and the grades of recommendations (A-D) are defined at the end of the "Major Recommendations" field.

Recommendations

  • It is recommended that preoperative somatosensory-evoked potentials (SEPs) be considered to aid in providing prognostic information in selected patients in whom clinical factors do not provide clear guidance if such information would potentially change treatment decisions (Quality of evidence, Class II; Strength of recommendation, B).
  • It is recommended that the prognostic value of clinical factors such as age, duration of symptoms, and preoperative neurological function results be considered and discussed with patients when surgical intervention for cervical spondylotic myelopathy (CSM) is considered (Quality of evidence, Class III; Strength of recommendation, D).

Summary

Controversy regarding the optimal treatment strategy for CSM still exists. An understanding of clinical factors that may predict surgical outcome is likely to play an important role in determining the optimal treatment paradigm in this population. Presently, there are significant limitations with the current medical literature that prevent making formal recommendations regarding the use of clinical prognostic factors in treatment algorithms. One of the major concerns is that validated outcome measures are not consistently used in the reported studies. Therefore, in some cases, the actual surgical results may not be optimally analyzed. In this setting, interstudy comparisons are difficult to interpret.

A number of the studies have been performed using only a single type of surgical procedure. The surgical approach may introduce a bias that could affect clinical outcome. The manner in which the various authors determined the duration of symptoms was unclear and difficult to standardize. In many cases, the true onset of symptoms may have preceded the actual time frame acknowledged by the patient. A number of studies evaluated patient age, yet there were significant variations in what age was considered elderly.

Although limited, there are some Class II data to suggest that SEPs may have a role in predicting surgical outcome in patients with CSM. In particular, normal preoperative median nerve potentials and/or normalization of potentials in the early decompression period appear to be associated with a more favorable outcome. Motor-evoked potentials are highly sensitive for detecting myelopathy, but there is a lack of data supporting its predictive value. Predominantly Class III data suggest that elderly patients may show neurological improvement postoperatively, but the study designs limit the effectiveness of a generalized comparison with younger patients. Thus, although this may be borne out in future studies, there is presently only Class III evidence supporting the use of patient age or duration of symptoms as prognostic indicators in the surgical outcome of patients with CSM.

Definitions:

Strength of the Evidence

Class I: Evidence evolved from well-designed randomized controlled trials (RCTs).

Class II: Evidence arose from RCTs with design problems or from well-designed cohort studies.

Class III: Evidence arose from case series or poorly designed cohort studies.

Strength of the Recommendations

Grade A: Recommendations based on consistent Class I studies.

Grade B: Recommendations based on a single Class I study or consistent Class II studies.

Grade C: Recommendations based on a single Class II study.

Grade D: Recommendations based on Class III or weaker data, or based on inconsistent data.

Clinical Algorithm(s)

None provided

Evidence Supporting the Recommendations

Type of Evidence Supporting the Recommendations

The type of supporting evidence is identified and graded for each recommendation (see "Major Recommendations").

Benefits/Harms of Implementing the Guideline Recommendations

Potential Benefits

Improved ability of practitioners to determine which patients with cervical spondylotic myelopathy (CSM) are most likely to benefit from surgical intervention

Potential Harms

In some cases, surgical management may result in worsened neurological functioning. Surgery may involve relatively complex decompression and stabilization procedures. The complication rate is not insignificant, particularly in the elderly.

Qualifying Statements

Qualifying Statements
  • During guideline development, the group commonly encountered unsophisticated or poorly designed comparative methods in clinical trials. The most common flaw was the lack of a control group or the utilization of historical controls. Other common flaws were invalid outcome measures, and the lack either of randomization or blinding of outcome assessors. Specific examples are provided in the text of each topic. At the conclusion of each chapter are suggestions for future areas of study and ideas to improve the quality of clinical research.
  • With each recommendation comes the risk of conformational bias. The recommendation of a therapeutic option presumes that functional and economic preferences have been determined. Reliable and valid outcome measures help in this respect. It is hoped that such functional and economic outcome measures represent the values important to the patient and society and less the practitioner. By focusing attention on outcome measures in each study, the values of the patient and society are represented in these guidelines.
  • To minimize any specialty bias, spinal surgeons from both orthopedic and neurosurgery departments participated in the creation of these guidelines. However, although invited, nonsurgical stakeholders did not participate—a circumstance that some might argue would predispose to conformational bias toward strong surgical recommendations. It is hoped in the future that nonsurgical stakeholders will participate. During this process, the entire group made a concerted effort to be unprejudiced. Many authors acknowledged that poor quality or controversial data often formed the basis of their predetermined ideas regarding standard treatment. It is expected that certain practitioners may disagree with the recommendations. However, with careful review of the scientific foundation, the critically thoughtful reader should find the recommendations warranted.

Implementation of the Guideline

Description of Implementation Strategy

An implementation strategy was not provided.

Institute of Medicine (IOM) National Healthcare Quality Report Categories

IOM Care Need
Getting Better
Living with Illness
IOM Domain
Effectiveness
Patient-centeredness

Identifying Information and Availability

Bibliographic Source(s)
Holly LT, Matz PG, Anderson PA, Groff MW, Heary RF, Kaiser MG, Mummaneni PV, Ryken TC, Choudhri TF, Vresilovic EJ, Resnick DK, Joint Section on Disorders of the Spine and Peripheral Nerves [trunc]. Clinical prognostic indicators of surgical outcome in cervical spondylotic myelopathy. J Neurosurg Spine. 2009 Aug;11(2):112-8. [19 references] PubMed External Web Site Policy
Adaptation

Not applicable: The guideline was not adapted from another source.

Date Released
2009 Aug
Guideline Developer(s)
American Association of Neurological Surgeons - Medical Specialty Society
Congress of Neurological Surgeons - Professional Association
Source(s) of Funding

Administrative costs of this project were funded by the Joint Section on Disorders of the Spine and Peripheral Nerves of the American Association of Neurological Surgeons and Congress of Neurological Surgeons.

Guideline Committee

Joint Section on Disorders of the Spine and Peripheral Nerves of the American Association of Neurological Surgeons and Congress of Neurological Surgeons Expert Group

Composition of Group That Authored the Guideline

Authors: Langston T. Holly, M.D., Division of Neurosurgery, David Geffen School of Medicine, University of California at Los Angeles, California; Paul G. Matz, M.D., Division of Neurological Surgery, University of Alabama, Birmingham, Alabama; Paul A. Anderson, M.D., Department of Orthopaedic Surgery, University of Wisconsin, Madison, Wisconsin; Michael W. Groff, M.D., Department of Neurosurgery, Harvard Medical School and Beth Israel Deaconess Medical Center, Boston, Massachusetts; Robert F. Heary, M.D., Department of Neurosurgery, University of Medicine and Dentistry of New Jersey—New Jersey Medical School, Newark, New Jersey; Michael G. Kaiser, M.D., Department of Neurological Surgery, Neurological Institute, Columbia University, New York, New York; Praveen V. Mummaneni, M.D., Department of Neurosurgery, University of California at San Francisco, California; Timothy C. Ryken, M.D., Department of Neurosurgery, University of Iowa Hospitals and Clinics, Iowa City, Iowa; Tanvir F. Choudhri, M.D., Department of Neurosurgery, Mount Sinai School of Medicine, New York, New York; Edward J. Vresilovic, M.D., Ph.D., Department of Orthopaedic Surgery, Milton S. Hershey Medical Center, Pennsylvania State College of Medicine, Hershey, Pennsylvania; Daniel K. Resnick, M.D., Department of Neurological Surgery, University of Wisconsin, Madison, Wisconsin

Financial Disclosures/Conflicts of Interest

No author received payment or honorarium for time devoted to this project. Dr. Resnick owns stock in Orthovita. Dr. Matz receives support from the Kyphon Grant for Thoracolumbar Fracture Study, and an advisory honorarium from Synthes for the cadaver laboratory. Dr. Heary receives support from DePuy Spine and Biomet Spine, and receives royalties from DePuy Spine and Zimmer Spine. Dr. Groff is a consultant for DePuy Spine. Dr. Mummaneni is a consultant for and receives university grants from DePuy Spine and Medtronic, Inc., and is a patent holder in DePuy Spine. Dr. Anderson is an owner of, consultant for, and stockholder of Pioneer Surgical Technology; a consultant for and receives non–study related support from Medtronic, Inc.; and is a patent holder in Stryker. The authors report no other conflicts of interest concerning the materials or methods used in this study or the findings specified in this paper.

Guideline Status

This is the current release of the guideline.

Guideline Availability

Electronic copies: Available from the Journal of Neurosurgery Web site External Web Site Policy.

Print copies: Available from the Journal of Neurosurgery Publishing Group, 1224 Jefferson Park Avenue, Suite 450, Charlottesville, Virginia 22903, USA. Telephone: 434-924-5503

Availability of Companion Documents

The following is available:

  • Introduction and methodology: guidelines for the surgical management of cervical degenerative disease. J Neurosurg Spine. 2009 Aug;11(2):101-3. Electronic copies: Available from the Journal of Neurosurgery Web site External Web Site Policy.
Patient Resources

None available

NGC Status

This NGC summary was completed by ECRI Institute on February 11, 2011. The information was verified by the guideline developer on March 20, 2011.

Copyright Statement

This NGC summary is based on the original guideline, which is subject to the guideline developer's copyright restrictions.

Disclaimer

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