Open Access, Peer-reviewed
pISSN 2093-4378
eISSN 2093-4386
    J Korean Soc Spine Surg. 2019 Jun;26(2):33-39. Korean.
    Published online Jun 30, 2019.
    https://doi.org/10.4184/jkss.2019.26.2.33
    © Copyright 2019 Korean Society of Spine Surgery
    Original Article

    Analysis of Preoperative Factors Affecting Postoperative Spinal Canal Expansion after Posterior Decompression for the Treatment of Multilevel Cervical Myelopathy

    Byung-Wan Choi, M.D., and Seung Chul Kim, M.D.
      • Department of Orthopedic Surgery, Inje University, Haeundae Paik Hospital, Busan, Korea.
    • Corresponding author: Byung Wan Choi, M.D. Department of Orthopedic Surgery, Inje University, Haeundae Paik Hospital Haeundae-ro, Haeundae-gu, Busan, 48108, Korea. TEL: +82-51-797-0240, FAX: +82-51-797-0249, Email: alla1013@naver.com
    Received December 19, 2018; Revised January 11, 2019; Accepted April 04, 2019.

    This is an Open Access article distributed under the terms of the Creative Commons Attribution Non-Commercial License (http://creativecommons.org/licenses/by-nc/4.0/) which permits unrestricted non-commercial use, distribution, and reproduction in any medium, provided the original work is properly cited.

    Abstract

    Study Design

    Retrospective analysis

    Objectives

    To evaluate preoperative factors related with spinal canal expansion after posterior decompression for the treatment of multilevel cervical myelopathy.

    Summary of Literature Review

    Data about preoperative factors related with spinal canal expansion after posterior cervical decompression surgery are inconsistent.

    Materials and Methods

    We reviewed 67 patients with cervical myelopathy who underwent posterior laminectomy or laminoplasty. Radiologically, we evaluated the C2-7 Cobb angle and range of motion using X-rays from the preoperative assessment and final follow-up. Expansion of the spinal canal at 6 weeks postoperatively was evaluated using magnetic resonance imaging and compared with the preoperative values. The preoperative factors of age, sex, number of operated levels, operation method, and radiological parameters were investigated as factors potentially related to postoperative spinal canal expansion using multivariate regression and correlation analyses. The clinical outcome was analyzed by the Neck Disability Index (NDI) and Japanese Orthopaedic Association (JOA) scores.

    Results

    The postoperative spinal canal expansion was 4.76 mm in sagittal images and 4.31 mm in axial images, with higher values observed in males and cases of severe preoperative cord compression. A lordotic preoperative Cobb angle was related to postoperative spinal canal expansion and JOA score improvement, but without statistical significance. The clinical outcomes of NDI (18.3→14.8) and JOA scores (10.81→14.6) showed improvement, but were not significantly related with any preoperative factors.

    Conclusions

    The amount of preoperative spinal canal stenosis was associated with postoperative spinal canal expansion after posterior decompression in multilevel cervical myelopathy. The preoperative Cobb angle was not related to postoperative spinal canal expansion or clinical improvement.

    Keywords
    Cervical myelopathy; Posterior decompression; Spinal canal expansion; MRI; Cobb angle

    Figures

    Fig. 1
    Patient inclusion flowchart.

    Fig. 2
    Severity of cord compression at the site of maximum compression was analyzed using T2-weighted sagittal and axial views on magnetic resonance imaging.
    (A) Sagittal occupy ratio was measured as B/A. (B) Axial occupy ratio was measured as B/A. (C, D) At the 6-week postoperative follow-up, the degree of spinal cord expansion was compared and analyzed with that prior to surgery as B-A.

    Tables

    Table 1
    Effect of demographic and radiological factors on postoperative increase of sagittal diameter (Multivariate regression analysis)

    Table 2
    Effect of demographic and radiological factors on postoperative increase of axial diameter (Multivariate regression analysis)

    Table 3
    Radiological and clinical analysis according to preoperative Cobb angle (Chi square, t-test)

    Table 4
    Correlation analysis between clinical outcomes and radiological factors.

    References

      1. Denaro V, Di Martino A. A cervical spine surgery: an historical perspective. Clin Orthop Relat Res 2011 Mar;469(3):639–648. [doi: 10.1007/s11999-010-1752-3]
      1. Rhee JM, Basra S. Posterior surgery for cervical myelopathy:laminectomy, laminectomy with fusion, and laminoplasty. Asian Spine J 2008;2(2):114–126. [doi: 10.4184/asj.2008.2.2.114]
      1. Aita I, Hayashi K, Wadano Y, Yabuki T. Posterior movement and enlargement of the spinal cord after cervical laminoplasty. J Bone Joint Surg Br 1998 Jan;80(1):33–37. [doi: 10.1302/0301-620x.80b1.7919]
      1. Fujimura Y, Nishi Y, Nakamura M. Dorsal shift and expansion of the spinal cord after expansive open-door laminoplasty. J Spinal Disord 1997 Aug;10(4):282–295. [doi: 10.1097/00002517-199708000-00002]
      1. Sodeyama T, Goto S, Mochizuki M, Takahashi J, Moriya H. Effect of decompression enlargement laminoplasty for posterior shifting of the spinal cord. Spine (Phila Pa 1976) 1999 Aug;24(15):1527–1531. [doi: 10.1097/00007632-199908010-00005]
      1. Tashjian VS, Kohan E, McArthur DL, Holly LT. The relationship between preoperative cervical alignment and postoperative spinal cord drift after decompressive laminectomy and arthrodesis for cervical spondylotic myelopathy. Surg Neurol 2009 Aug;72(2):112–117. [doi: 10.1016/j.surneu.2009.02.024]
      1. Du W, Zhang P, Shen Y, Zhang YZ, Ding WY, Ren LX. Enlarged laminectomy and lateral mass screw fixation for multilevel cervical degenerative myelopathy associated with kyphosis. Spine J 2014 Jan;14(1):57–64. [doi: 10.1016/j.spinee.2013.06.017]
      1. Denaro V, Longo UG, Berton A, Salvatore G, Denaro L. Cervical spondylotic myelopathy: the relevance of the spinal cord back shift after posterior multilevel decompression. A systematic review. Eur Spine J 2015 Nov;24 S7:832–841. [doi: 10.1007/s00586-015-4299-x]
      1. Hirabayashi K, Satomi K. Operative procedure and results of expansive open-door laminoplasty. Spine (Phila Pa 1976) 1998;13:870–876.
      1. Song KJ, Choi BW, Kim JK. Adjacent segment pathology following anterior decompression and fusion using cage and plate for the treatment of degenerative cervical spinal diseases. Asian Spine J 1988 Jun;13(7):870–876. [doi: 10.1097/00007632-198807000-00032]
      1. Baba H, Uchida K, Maezawa Y, Furusawa N, Azuchi M, Imura S. Lordotic alignment and posterior migration of the spinal cord following en bloc open-door laminoplasty for cervical myelopathy: a magnetic resonance imaging study. J Neurol 1996;243(9):626–632. [doi: 10.1007/bf00878657]
      1. Hatta Y, Shiraishi T, Hase H, Yato Y, Ueda S, Mikami Y, Harada T, Ikeda T, Kubo T. Is posterior spinal cord shifting by extensive posterior decompression clinically significant for multisegmental cervical spondylotic myelopathy? Spine (Phila Pa 1976) 2005 Nov;30(21):2414–2419. [doi: 10.1097/01.brs.0000184751.80857.3e]
      1. Lee JY, Sharan A, Baron EM, Lim MR, Grossman E, Albert TJ, Vaccaro AR, Hilibrand AS. Quantitative prediction of spinal cord drift after cervical laminectomy and arthrodesis. Spine (Phila Pa 1976) 2006 Jul;31(16):1795–1798. [doi: 10.1097/01.brs.0000225992.26154.d0]
      1. Shiozaki T, Otsuka H, Nakata Y, Yokoyama T, Takeuchi K, Ono A, Numasawa T, Wada K, Toh S. Spinal cord shift on magnetic resonance imaging at 24 hours after cervical laminoplasty. Spine (Phila Pa 1976) 2009 Feb;34(3):274–279. [doi: 10.1097/brs.0b013e318194e275]
      1. Fujimura Y, Nishi Y, Nakamura M. Dorsal shift and expansion of the spinal cord after expansive open-door laminoplasty. J Spinal Disord 1997;10:282–287.
      1. Yoon ST, Raich A, Hashimoto RE, Riew KD, Shaffrey CI, Rhee JM, Tetreault LA, Skelly AC, Fehlings MG. Predictive factors affecting outcome after cervical laminoplasty. Spine (Phila Pa 1976) 2013 Oct;38:232–252. [doi: 10.1097/brs.0b013e3182a7eb55]
      1. Ranger MR, Irwin GJ, Bunbury KM, Peutrell JM. Changing body position alters the location of the spinal cord within the vertebral canal: a magnetic resonance imaging study. Br J Anaesth 2008 Dec;101(6):804–809. [doi: 10.1093/bja/aen295]
      1. Kato Y, Iwasaki M, Fuji T, Yonenobu K, Ochi T. Long term follow-up results of laminectomy for cervical myelopathy caused by ossification of the posterior longitudinal ligament. J Neurosurg 1998 Aug;89(2):217–223. [doi: 10.3171/jns.1998.89.2.0217]
    MeSH Terms
    Asian Continental Ancestry Group
    Constriction, Pathologic
    Decompression*
    Follow-Up Studies
    Humans
    Laminectomy
    Laminoplasty
    Magnetic Resonance Imaging
    Male
    Methods
    Neck
    Range of Motion, Articular
    Retrospective Studies
    Spinal Canal*
    Spinal Cord Diseases*
    Metrics
    Share
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    Tables
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