The Length of the Cervical Cord: Effects of Postural Changes in Healthy Volunteers Using Positional Magnetic Resonance Imaging

Kuwazawa, Yasuyuki; Pope, Malcolm H.; Bashir, Waseem; Takahashi, Keisuke; Smith, Francis W.

doi:10.1097/01.brs.0000229228.62627.75

Cited by 47 publications

(28 citation statements)

References 11 publications

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“…MRI studies have measured the cord length in cervical flexion, extension, and neutral position in healthy [17] and CSM [18] patients. These studies consistently reported lengthening of the cord in flexion as compared to neutral or extension.…”

Section: Discussionmentioning

confidence: 99%

Addressing Stretch Myelopathy in Multilevel Cervical Kyphosis with Posterior Surgery Using Cervical Pedicle Screws

et al. 2016

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Study DesignTechnique description and retrospective data analysis.PurposeTo describe the technique of cervical kyphosis correction with partial facetectomies and evaluate the outcome of single-stage posterior decompression and kyphosis correction in multilevel cervical myelopathy.Overview of LiteratureKyphosis correction in multilevel cervical myelopathy involves anterior and posterior surgery. With the advent of cervical pedicle screw-rod instrumentation, single-stage posterior kyphosis correction is feasible and can address stretch myelopathy by posterior shortening.MethodsNine patients underwent single-stage posterior decompression and kyphosis correction for multilevel cervical myelopathy using cervical pedicle screw instrumentation from March 2011 to February 2014 and were evaluated preoperatively and postoperatively with modified Japanese Orthopaedic Association (mJOA) scoring and computed tomography scans for radiological measurements. Kyphosis assessment was made with Ishihara curvature index and C2–C7 Cobb's angle. The linear length of the spinal canal and the actual spinal canal length were also evaluated. The average follow-up was 40.56 months (range, 20 to 53 months).ResultsThe average preoperative C2–7 Cobb's angle of 6.3° (1° to 12°) improved to 2° (10° to −9°). Ishihara index improved from −15.8% (−30.5% to −4.7%) to −3.66% (−14.5% to +12.6%). The actual spinal canal length decreased from 83.64 mm (range, 76.8 to 91.82 mm) to 82.68 mm (range, 75.85 to 90.78 mm). The preoperative mJOA score of 7.8 (range, 3 to 11) improved to 15.0 (range, 13 to 17).ConclusionsSingle-stage posterior decompression and kyphosis correction using cervical pedicle screws for multilevel cervical myelopathy may address stretch myelopathy, in addition to decompression in the transverse plane. However, cervical lordosis was not achieved with this method as predictably as by the anterior approach. The present study shows evidence of mild shortening of cervical spinal canal and a positive correlation between canal shortening and clinical improvement.

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Section: Discussionmentioning

confidence: 99%

Addressing Stretch Myelopathy in Multilevel Cervical Kyphosis with Posterior Surgery Using Cervical Pedicle Screws

et al. 2016

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“…Additionally, Kuwazawa et al [9, 10] demonstrated the dynamic effects of postural changes on the cervical cord using positional MRI.…”

Section: Discussionmentioning

confidence: 99%

The relationship between the cervical spinal canal diameter and the pathological changes in the cervical spine

et al. 2009

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A congenitally narrow cervical spinal canal has been established as an important risk factor for the development of cervical spondylotic myelopathy. However, few reports have described the mechanism underlying this risk. In this study, we investigate the relationship between cervical spinal canal narrowing and pathological changes in the cervical spine using positional magnetic resonance imaging (MRI). Two hundred and ninety-five symptomatic patients underwent cervical MRI in the weight-bearing position with dynamic motion (flexion, neutral, and extension) of the cervical spine. The sagittal cervical spinal canal diameter and cervical segmental angular motion were measured and calculated. Each segment was assessed for the extent of intervertebral disc degeneration and cervical cord compression. Based on the sagittal canal diameter, the subjects were classified into three groups: A, subjects with a congenitally narrow canal, diameter of less than 13 mm; B, subjects with a normal canal, diameter of 13–15 mm; C, subjects with a wide canal, diameter of more than 15 mm. When compared with Groups A and B, the disc degeneration grades at the C3-4, C5-6, and C6-7 segments and the cervical cord compression scores at the C3-4 and C5-6 segments showed significant differences. Additionally, when compare with Groups A and C, the disc degeneration grades at all segments, except C2-3, and the cervical cord compression scores at all segments, except C2-3, showed significant differences. With respect to the cervical kinematics, few differences in the kinematics were observed between Groups B and C, however, the kinematics in Group A was different with other two groups. In Group A, the segmental mobility at the C4-5 and C6-7 segments were significantly higher than those observed in Group B, and the segmental mobility at the C3-4 segment was significantly lower than that observed in Groups B or C. We demonstrated the unique pathological and kinematic traits of cervical spine that exist in a congenitally narrow canal. We hypothesize that kinematic trait associated with a congenitally narrow canal may greatly contribute to pathological changes in the cervical spine. Our results suggest that cervical spinal canal diameter of less than 13 mm may be associated with an increased risk for development of pathological changes in cervical intervertebral discs. Subsequently, the presence of a congenitally narrow canal can expose individuals to a greater risk of developing cervical spinal stenosis.

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“…2,[7][8][9][10][11] It may also help in understanding the true nature of spinal pathologies. In addition, it can demonstrate the mobility of each motion segment and finally, relate the mobility to the changes in sagittal alignment and disc degeneration.…”

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confidence: 99%

Kinematic Analysis of the Relationship Between Sagittal Alignment and Disc Degeneration in the Cervical Spine

Miyazaki¹,

Hymanson²,

Morishita³

et al. 2008

Spine

117

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The Length of the Cervical Cord: Effects of Postural Changes in Healthy Volunteers Using Positional Magnetic Resonance Imaging

Abstract: We found posture-dependent differences of the length of the cervical cord in the recumbent and erect series. These results may be important when assessing the dynamic factor in cervical spondylotic myelopathy.

Cited by 47 publications

References 11 publications

Addressing Stretch Myelopathy in Multilevel Cervical Kyphosis with Posterior Surgery Using Cervical Pedicle Screws

Addressing Stretch Myelopathy in Multilevel Cervical Kyphosis with Posterior Surgery Using Cervical Pedicle Screws

The relationship between the cervical spinal canal diameter and the pathological changes in the cervical spine

Kinematic Analysis of the Relationship Between Sagittal Alignment and Disc Degeneration in the Cervical Spine

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