Perspectives Commentary on: Predictors of Outcome in Patients with Cervical Spondylotic Myelopathy Undergoing Surgical Treatment: A Survey of Members from AOSpine International by Tetreault et al. pp. 623-633.
Bernhard Meyer, M.D. Professor and Chairman, Department of Neurosurgery Director, Neurosurgical Clinic, Technical University of Munich
Quest for Level I Evidence in the Treatment of Cervical Spondylotic Myelopathy Sandro M. Krieg and Bernhard Meyer
eurosurgeons consider decompressive surgery the treatment of choice in cervical spondylotic myelopathy. Many studies have described and evaluated anterior, posterior, instrumented, and noninstrumented surgical approaches (1, 2, 4). Although an economic advantage was shown for the anterior approach, clinical outcome was shown to be comparable; there is no clear evidence in the literature regarding which approach is superior in terms of clinical outcome (6, 10).
N
decompression for cervical spondylotic myelopathy. A systematic review by Holly et al. (7) showed that there is class III evidence for age, duration of symptoms, and preoperative neurologic function to affect the outcome independently. A more recent review by Tetreault et al. (11) found longer duration of symptoms and poor Japanese Orthopedic Association baseline scores to be associated with a worse outcome but not age.
Although there is still no level I evidence that surgical decompression is superior to conservative treatment, more recent data showed that spinal decompression not only can stop progression but also can lead to functional improvement in some patients (3, 5, 12). However, the appropriateness of nonsurgical management in patients with minimal symptoms is still under discussion (8). Because of the heterogeneity of the disease, it remains unclear if level I evidence can be provided for timing, indication, and surgical approach. Comorbidities, such as diabetes, lumbar spinal stenosis, or radiculopathy, and the wide age range of patients contribute to the huge variety of patient characteristics, as does the varying severity of myelopathy itself. It would be very difficult to enroll a homogeneous cohort of patients for a randomized trial on cervical spondylotic myelopathy.
We are unsure about the added value of the present article by Tetreault et al. We seem to learn nothing from this article other than the fact that a few AOSpine members perceive factors that are already extensively discussed in the literature as important predictors. I would say this is not very surprising. Some of AOSpine members surveyed just seem to have read the authors’ excellent clinical work that was published previously, including a prospective clinical trial focusing on predictors of outcome after decompressive surgery for cervical spondylotic myelopathy, which already proved younger age, higher baseline Modified Japanese Orthopedic Association score, and shorter duration of symptoms to be predictors for a favorable clinical outcome (9) and the aforementioned systematic review (11). Tetreault et al. are very convincing, which is good to know! However, with regard to cervical spondylotic myelopathy, we are no closer to knowing when to operate, on whom, and how.
In the meantime, it is worthwhile to elaborate on predictive factors that lead to a more favorable outcome after surgical
Key words AOSpine International - Baseline severity score - Cervical spondylotic myelopathy - Clinical factors - Combined T1/T2 signal changes - Duration of symptoms - Imaging factors - Predictors of surgical outcome - Signal intensity on T2-weighted images - Survey results -
WORLD NEUROSURGERY 81 [3/4]: 501-502, MARCH/APRIL 2014
Department of Neurosurgery, Technical University of Munich, Munich, Germany To whom correspondence should be addressed: Bernhard Meyer, M.D. [E-mail: [email protected]] Citation: World Neurosurg. (2014) 81, 3/4:501-502. http://dx.doi.org/10.1016/j.wneu.2013.10.041
www.WORLDNEUROSURGERY.org
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PERSPECTIVES
REFERENCES 1. Aronson N, Filtzer DL, Bagan M: Anterior cervical fusion by the Smith-Robinson approach. J Neurosurg 29:396-404, 1968. 2. Bailey RW, Badgley CE: Stabilization of the cervical spine by anterior fusion. J Bone Joint Surg Am 42:565-594, 1960. 3. Baptiste DC, Fehlings MG: Pathophysiology of cervical myelopathy. Spine J 6(6 Suppl):190S-197S, 2006. 4. Casotto A, Buoncristiani P: Posterior approach in cervical spondylotic myeloradiculopathy. Acta Neurochir (Wien) 57:275-285, 1981. 5. Fehlings MG, Arvin B: Surgical management of cervical degenerative disease: the evidence related to indications, impact, and outcome. J Neurosurg Spine 11:97-100, 2009. 6. Ghogawala Z, Martin B, Benzel EC, Dziura J, Magge SN, Abbed KM, Bisson EF, Shahid J, Coumans JV, Choudhri TF, Steinmetz MP,
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www.SCIENCEDIRECT.com
Krishnaney AA, King JT Jr, Butler WE, Barker FG 2nd, Heary RF: Comparative effectiveness of ventral vs dorsal surgery for cervical spondylotic myelopathy. Neurosurgery 68:622-630, 2011 [discussion 630-621]. 7. Holly LT, Matz PG, Anderson PA, Groff MW, Heary RF, Kaiser MG, Mummaneni PV, Ryken TC, Choudhri TF, Vresilovic EJ, Resnick DK: Clinical prognostic indicators of surgical outcome in cervical spondylotic myelopathy. J Neurosurg Spine 11:112-118, 2009. 8. Kadanka Z, Bednarik J, Vohanka S, Vlach O, Stejskal L, Chaloupka R, Filipovicova D, Surelova D, Adamova B, Novotny O, Nemec M, Smrcka V, Urbanek I: Conservative treatment versus surgery in spondylotic cervical myelopathy: a prospective randomised study. Eur Spine J 9:538-544, 2000.
10. Lawrence BD, Jacobs WB, Norvell DC, Hermsmeyer JT, Chapman JR, Brodke DS: Anterior versus posterior approach for treatment of cervical spondylotic myelopathy: a systematic review. Spine. (Phila Pa 1976) 38(22 Suppl 1):S173-S182, 2013. 11. Tetreault LA, Karpova A, Fehlings MG: Predictors of outcome in patients with degenerative cervical spondylotic myelopathy undergoing surgical treatment: results of a systematic review. Eur Spine J 2013 Feb 6 [Epub ahead of print]. 12. Tracy JA, Bartleson JD: Cervical spondylotic myelopathy. Neurologist 16:176-187, 2010.
Citation: World Neurosurg. (2014) 81, 3/4:501-502. http://dx.doi.org/10.1016/j.wneu.2013.10.041 Journal homepage: www.WORLDNEUROSURGERY.org
9. Karpova A, Arun R, Davis AM, Kulkarni AV, Massicotte EM, Mikulis DJ, Lubina ZI, Fehlings MG: Predictors of surgical outcome in cervical spondylotic myelopathy. Spine. (Phila Pa 1976) 38:392-400, 2013.
Available online: www.sciencedirect.com 1878-8750/$ - see front matter ª 2014 Elsevier Inc. All rights reserved.
WORLD NEUROSURGERY, http://dx.doi.org/10.1016/j.wneu.2013.10.041
Bernhard Meyer, M.D. Professor and Chairman, Department of Neurosurgery Director, Neurosurgical Clinic, Technical University of Munich
Quest for Level I Evidence in the Treatment of Cervical Spondylotic Myelopathy Sandro M. Krieg and Bernhard Meyer
eurosurgeons consider decompressive surgery the treatment of choice in cervical spondylotic myelopathy. Many studies have described and evaluated anterior, posterior, instrumented, and noninstrumented surgical approaches (1, 2, 4). Although an economic advantage was shown for the anterior approach, clinical outcome was shown to be comparable; there is no clear evidence in the literature regarding which approach is superior in terms of clinical outcome (6, 10).
N
decompression for cervical spondylotic myelopathy. A systematic review by Holly et al. (7) showed that there is class III evidence for age, duration of symptoms, and preoperative neurologic function to affect the outcome independently. A more recent review by Tetreault et al. (11) found longer duration of symptoms and poor Japanese Orthopedic Association baseline scores to be associated with a worse outcome but not age.
Although there is still no level I evidence that surgical decompression is superior to conservative treatment, more recent data showed that spinal decompression not only can stop progression but also can lead to functional improvement in some patients (3, 5, 12). However, the appropriateness of nonsurgical management in patients with minimal symptoms is still under discussion (8). Because of the heterogeneity of the disease, it remains unclear if level I evidence can be provided for timing, indication, and surgical approach. Comorbidities, such as diabetes, lumbar spinal stenosis, or radiculopathy, and the wide age range of patients contribute to the huge variety of patient characteristics, as does the varying severity of myelopathy itself. It would be very difficult to enroll a homogeneous cohort of patients for a randomized trial on cervical spondylotic myelopathy.
We are unsure about the added value of the present article by Tetreault et al. We seem to learn nothing from this article other than the fact that a few AOSpine members perceive factors that are already extensively discussed in the literature as important predictors. I would say this is not very surprising. Some of AOSpine members surveyed just seem to have read the authors’ excellent clinical work that was published previously, including a prospective clinical trial focusing on predictors of outcome after decompressive surgery for cervical spondylotic myelopathy, which already proved younger age, higher baseline Modified Japanese Orthopedic Association score, and shorter duration of symptoms to be predictors for a favorable clinical outcome (9) and the aforementioned systematic review (11). Tetreault et al. are very convincing, which is good to know! However, with regard to cervical spondylotic myelopathy, we are no closer to knowing when to operate, on whom, and how.
In the meantime, it is worthwhile to elaborate on predictive factors that lead to a more favorable outcome after surgical
Key words AOSpine International - Baseline severity score - Cervical spondylotic myelopathy - Clinical factors - Combined T1/T2 signal changes - Duration of symptoms - Imaging factors - Predictors of surgical outcome - Signal intensity on T2-weighted images - Survey results -
WORLD NEUROSURGERY 81 [3/4]: 501-502, MARCH/APRIL 2014
Department of Neurosurgery, Technical University of Munich, Munich, Germany To whom correspondence should be addressed: Bernhard Meyer, M.D. [E-mail: [email protected]] Citation: World Neurosurg. (2014) 81, 3/4:501-502. http://dx.doi.org/10.1016/j.wneu.2013.10.041
www.WORLDNEUROSURGERY.org
501
PERSPECTIVES
REFERENCES 1. Aronson N, Filtzer DL, Bagan M: Anterior cervical fusion by the Smith-Robinson approach. J Neurosurg 29:396-404, 1968. 2. Bailey RW, Badgley CE: Stabilization of the cervical spine by anterior fusion. J Bone Joint Surg Am 42:565-594, 1960. 3. Baptiste DC, Fehlings MG: Pathophysiology of cervical myelopathy. Spine J 6(6 Suppl):190S-197S, 2006. 4. Casotto A, Buoncristiani P: Posterior approach in cervical spondylotic myeloradiculopathy. Acta Neurochir (Wien) 57:275-285, 1981. 5. Fehlings MG, Arvin B: Surgical management of cervical degenerative disease: the evidence related to indications, impact, and outcome. J Neurosurg Spine 11:97-100, 2009. 6. Ghogawala Z, Martin B, Benzel EC, Dziura J, Magge SN, Abbed KM, Bisson EF, Shahid J, Coumans JV, Choudhri TF, Steinmetz MP,
502
www.SCIENCEDIRECT.com
Krishnaney AA, King JT Jr, Butler WE, Barker FG 2nd, Heary RF: Comparative effectiveness of ventral vs dorsal surgery for cervical spondylotic myelopathy. Neurosurgery 68:622-630, 2011 [discussion 630-621]. 7. Holly LT, Matz PG, Anderson PA, Groff MW, Heary RF, Kaiser MG, Mummaneni PV, Ryken TC, Choudhri TF, Vresilovic EJ, Resnick DK: Clinical prognostic indicators of surgical outcome in cervical spondylotic myelopathy. J Neurosurg Spine 11:112-118, 2009. 8. Kadanka Z, Bednarik J, Vohanka S, Vlach O, Stejskal L, Chaloupka R, Filipovicova D, Surelova D, Adamova B, Novotny O, Nemec M, Smrcka V, Urbanek I: Conservative treatment versus surgery in spondylotic cervical myelopathy: a prospective randomised study. Eur Spine J 9:538-544, 2000.
10. Lawrence BD, Jacobs WB, Norvell DC, Hermsmeyer JT, Chapman JR, Brodke DS: Anterior versus posterior approach for treatment of cervical spondylotic myelopathy: a systematic review. Spine. (Phila Pa 1976) 38(22 Suppl 1):S173-S182, 2013. 11. Tetreault LA, Karpova A, Fehlings MG: Predictors of outcome in patients with degenerative cervical spondylotic myelopathy undergoing surgical treatment: results of a systematic review. Eur Spine J 2013 Feb 6 [Epub ahead of print]. 12. Tracy JA, Bartleson JD: Cervical spondylotic myelopathy. Neurologist 16:176-187, 2010.
Citation: World Neurosurg. (2014) 81, 3/4:501-502. http://dx.doi.org/10.1016/j.wneu.2013.10.041 Journal homepage: www.WORLDNEUROSURGERY.org
9. Karpova A, Arun R, Davis AM, Kulkarni AV, Massicotte EM, Mikulis DJ, Lubina ZI, Fehlings MG: Predictors of surgical outcome in cervical spondylotic myelopathy. Spine. (Phila Pa 1976) 38:392-400, 2013.
Available online: www.sciencedirect.com 1878-8750/$ - see front matter ª 2014 Elsevier Inc. All rights reserved.
WORLD NEUROSURGERY, http://dx.doi.org/10.1016/j.wneu.2013.10.041
