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Impact of dynamic alignment, motion, and center of rotation on myelopathy grade and regional disability in cervical spondylotic myelopathy.

Publication ,  Journal Article
Liu, S; Lafage, R; Smith, JS; Protopsaltis, TS; Lafage, VC; Challier, V; Shaffrey, CI; Radcliff, K; Arnold, PM; Chapman, JR; Schwab, FJ ...
Published in: J Neurosurg Spine
December 2015

OBJECT: Cervical stenosis is a defining feature of cervical spondylotic myelopathy (CSM). Matsunaga et al. proposed that elements of stenosis are both static and dynamic, where the dynamic elements magnify the canal deformation of the static state. For the current study, the authors hypothesized that dynamic changes may be associated with myelopathy severity and neck disability. This goal of this study was to present novel methods of dynamic motion analysis in CSM. METHODS: A post hoc analysis was performed of a prospective, multicenter database of patients with CSM from the AOSpine North American study. One hundred ten patients (34%) met inclusion criteria, which were symptomatic CSM, age over 18 years, baseline flexion/extension radiographs, and health-related quality of life (HRQOL) questionnaires (modified Japanese Orthopaedic Association [mJOA] score, Neck Disability Index [NDI], the 36-Item Short Form Health Survey Physical Component Score [SF-36 PCS], and Nurick grade). The mean age was 56.9 ± 12 years, and 42% of patients were women (n = 46). Correlations with HRQOL measures were analyzed for regional (cervical lordosis and cervical sagittal vertical axis) and focal parameters (kyphosis and spondylolisthesis between adjacent vertebrae) in flexion and extension. Baseline dynamic parameters (flexion/extension cone relative to a fixed C-7, center of rotation [COR], and range of motion arc relative to the COR) were also analyzed for correlations with HRQOL measures. RESULTS: At baseline, the mean HRQOL measures demonstrated disability and the mean radiographic parameters demonstrated sagittal malalignment. Among regional parameters, there was a significant correlation between decreased neck flexion (increased C2-7 angle in flexion) and worse Nurick grade (R = 0.189, p = 0.048), with no significant correlations in extension. Focal parameters, including increased C-7 sagittal translation overT-1 (slip), were significantly correlated with greater myelopathy severity (mJOA score, Flexion R = -0.377, p = 0.003; mJOA score, Extension R = -0.261, p = 0.027). Sagittal slip at C-2 and C-4 also correlated with worse HRQOL measures. Reduced flexion/extension motion cones, a more posterior COR, and smaller range of motion correlated with worse general health SF-36 PCS and Nurick grade. CONCLUSIONS: Dynamic motion analysis may play an important role in understanding CSM. Focal parameters demonstrated a significant correlation with worse HRQOL measures, especially increased C-7 sagittal slip in flexion and extension. Novel methods of motion analysis demonstrating reduced motion cones correlated with worse myelopathy grades. More posterior COR and smaller range of motion were both correlated with worse general health scores (SF-36 PCS and Nurick grade). To our knowledge, this is the first study to demonstrate correlation of dynamic motion and listhesis with disability and myelopathy in CSM.

Duke Scholars

Published In

J Neurosurg Spine

DOI

EISSN

1547-5646

Publication Date

December 2015

Volume

23

Issue

6

Start / End Page

690 / 700

Location

United States

Related Subject Headings

  • Spondylosis
  • Spinal Cord Diseases
  • Range of Motion, Articular
  • Quality of Life
  • Prospective Studies
  • Orthopedics
  • Middle Aged
  • Male
  • Humans
  • Female
 

Citation

APA
Chicago
ICMJE
MLA
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Liu, S., Lafage, R., Smith, J. S., Protopsaltis, T. S., Lafage, V. C., Challier, V., … Ames, C. P. (2015). Impact of dynamic alignment, motion, and center of rotation on myelopathy grade and regional disability in cervical spondylotic myelopathy. J Neurosurg Spine, 23(6), 690–700. https://doi.org/10.3171/2015.2.SPINE14414
Liu, Shian, Renaud Lafage, Justin S. Smith, Themistocles S. Protopsaltis, Virginie C. Lafage, Vincent Challier, Christopher I. Shaffrey, et al. “Impact of dynamic alignment, motion, and center of rotation on myelopathy grade and regional disability in cervical spondylotic myelopathy.J Neurosurg Spine 23, no. 6 (December 2015): 690–700. https://doi.org/10.3171/2015.2.SPINE14414.
Liu S, Lafage R, Smith JS, Protopsaltis TS, Lafage VC, Challier V, et al. Impact of dynamic alignment, motion, and center of rotation on myelopathy grade and regional disability in cervical spondylotic myelopathy. J Neurosurg Spine. 2015 Dec;23(6):690–700.
Liu, Shian, et al. “Impact of dynamic alignment, motion, and center of rotation on myelopathy grade and regional disability in cervical spondylotic myelopathy.J Neurosurg Spine, vol. 23, no. 6, Dec. 2015, pp. 690–700. Pubmed, doi:10.3171/2015.2.SPINE14414.
Liu S, Lafage R, Smith JS, Protopsaltis TS, Lafage VC, Challier V, Shaffrey CI, Radcliff K, Arnold PM, Chapman JR, Schwab FJ, Massicotte EM, Yoon ST, Fehlings MG, Ames CP. Impact of dynamic alignment, motion, and center of rotation on myelopathy grade and regional disability in cervical spondylotic myelopathy. J Neurosurg Spine. 2015 Dec;23(6):690–700.

Published In

J Neurosurg Spine

DOI

EISSN

1547-5646

Publication Date

December 2015

Volume

23

Issue

6

Start / End Page

690 / 700

Location

United States

Related Subject Headings

  • Spondylosis
  • Spinal Cord Diseases
  • Range of Motion, Articular
  • Quality of Life
  • Prospective Studies
  • Orthopedics
  • Middle Aged
  • Male
  • Humans
  • Female