Faculty Bibliography

OBJECT/OBJECTIVE: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/OBJECTIVE: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/OBJECTIVE: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/OBJECTIVE: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/OBJECTIVE: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 >or= 2 mm is a more reliable indicator for pseudarthrosis than angular motion of 2 degrees 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/OBJECTIVE: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 Surgeons/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.

OBJECT/OBJECTIVE: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/OBJECTIVE: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/OBJECTIVE: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.

OBJECT/OBJECTIVE: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, approximately 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).