This is the current release of the guideline.

Cervical degenerative myelopathy (cervical spondylotic myelopathy)

Patients with cervical spondylotic myelopathy

Cervical laminectomy

Note: Timing of cervical laminectomy was considered, but there is insufficient evidence to make a recommendation.

Search Criteria

The expert group search of the National Library of Medicine and the Cochrane Database for the period from 1966 through 2007 using the MeSH subject headings of "cervical" and "surgery" and limited to humans generated a broad base of studies (9,589 references). The group reviewed the titles and abstracts with attention to those titles addressing clinical management. They followed the initial search with a secondary search crossing "myelopathy" with "surgery" and "cervical" and "myelopathy," and then reviewed the bibliographies of selected papers for additional relevant references.

The expert group selected articles if they addressed issues related to surgical management of cervical myelopathy. Articles with data on anterior approaches were included if they contained comparative data for posterior surgical approaches; articles were excluded if they addressed anterior approaches only because this topic is addressed in a separate section of these Guidelines. Finally, the expert group also excluded articles that did not contain clinical information relevant to laminectomy outcomes. Only papers providing data in a minimum of 15 patients undergoing cervical laminectomy for cervical spondylotic myelopathy (CSM) with a minimum of 1-year follow-up data were included in the evidentiary table (see Table 1 in the original guideline document).

Not stated

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.

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.

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 ) (see the "Rating Scheme for the Strength of the Recommendations" field).

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.

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

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.

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

Indications

Laminectomy is recommended as a surgical treatment option for symptomatic cervical spondylotic myelopathy (CSM) in selected patients in whom the risk of postoperative kyphosis is felt to be minimal (Quality of evidence, Class III; Strength of recommendation, D).

Technique

Laminectomy is recommended as a surgical treatment option for symptomatic cervical myelopathy. The limitations of the technique are an increased risk of postoperative kyphosis compared to anterior techniques, laminoplasty, or laminectomy with fusion. However, the development of kyphosis does not appear to diminish clinical outcome (Quality of evidence, Class III; Strength of recommendation, D).

Timing

There is insufficient evidence to make a recommendation regarding timing.

Summary

Historically, cervical laminectomies have been a safe and direct method for decompressing cervical spinal cord compression causing myelopathy. Large case series from the 1960s and 1970s and earlier have supported the use of this technique. At present laminectomy remains a viable consideration for the surgical management of cervical myelopathy. Concern has been raised over the development of postlaminectomy spinal instability, which may occur in 14% to 47% of patients who have had surgery for CSM. Whether this is related to reports of delayed deterioration in selected patients is not clear. Although postlaminectomy kyphosis may be frequently observed radiographically, it is less clear how it relates to the development of clinical symptoms. A straight or kyphotic alignment of the spine may predict a greater chance of late instability and kyphosis. Thus far, however, no study has clearly demonstrated a relationship between postlaminectomy kyphosis and deterioration in the quality of life of the patient.

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.

None provided

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

Appropriate use of cervical laminectomy for treatment of patients with cervical spondylotic myelopathy (CSM)

Concern has been raised over the development of postlaminectomy spinal instability, which may occur in 14% to 47% of patients who have had surgery for cervical spondylotic myelopathy (CSM). Whether this is related to reports of delayed deterioration in selected patients is not clear. Although postlaminectomy kyphosis may be frequently observed radiographically, it is less clear how it relates to the development of clinical symptoms.

An implementation strategy was not provided.

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

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.

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

Authors: Timothy C. Ryken, M.D., Department of Neurosurgery, University of Iowa Hospitals and Clinics, Iowa City, Iowa; Robert F. Heary, M.D., Department of Neurosurgery, University of Medicine and Dentistry of New Jersey—New Jersey Medical School, Newark, New Jersey; Paul G. Matz, M.D., Division of Neurological Surgery, University of Alabama, Birmingham, Alabama; Paul A. Anderson, M.D., Department of Orthopedic 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; Langston T. Holly, M.D., Division of Neurosurgery, David Geffen School of Medicine, University of California at Los Angeles, California; 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; 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 Orthopedic 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

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.

This is the current release of the guideline.

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

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

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 .

None available

This NGC summary was completed by ECRI Institute on February 12, 2011. The information was verified by the guideline developer on March 20, 2011.

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