Segmental Instability in Cervical Spondylotic Myelopathy With Severe Disc Degeneration

Abstract Background: Dynamic somatosensory evoked potentials (DSSEP) can be used to disclose abnormalities of ascending sensory pathways at dynamic positions and diagnose cervical spondylotic myelopathy (CSM). However, radiographic tests including magnetic resonance imaging (MRI) and dynamic X-ray are used much more widely in the management of CSM. Our study aims to clarify the correlations between several radiographic parameters and the DSSEP results, and further determine their reliability with clinical data.Methods: We retrospectively enrolled 38 CSM patients with surgical intervention. DSSEP tests were performed before surgery. Amplitude ratios of DSSEP N13 and N20 waves at extension and flexion were calculated and recorded as N13_E, N20_E, N13_F, N20_F respectively. Baseline severity was evaluated with the modified Japanese Orthopedic Association (mJOA) score and the Nurick grades. Prognosis was evaluated based on the 2-year recovery rate. Sagittal diameter and transverse areas of the cord and canal were measured and the Spinal cord/Canal Area Ratio were calculated. The compressive ratios at the compressed site (Compression_Ratio), central (Central_Ratio) and 1/4-lateral points (1/4-Lateral_Compression_Ratio), and intramedullary T2 hyperintensity patterns (Ax-CCM types) were also collected from MRI axial images. Dynamic X-rays were used to test for segmental instability of the cervical spine. The correlations between radiologic findings, DSSEP data, and clinical assessments were investigated.Results: We found that DSSEP N13_E and N13_F correlated with the Compression_Ratio, Central_Ratio, 1/4-Lateral_Compression_Ratio (Pearson, p<0.05) and Ax-CCM types (ANOVA, p<0.05) in MRI axial images and cervical segmental instability in dynamic X-ray (t-test, p<0.05). Apart from the 1/4-Lateral_Compression_Ratio, these radiographic parameters above also correlated with the baseline clinical assessments (Spearman or ANOVA or t-test, p<0.05) and postoperative recovery rate (Pearson or ANOVA or t-test, p<0.05).Conclusions: We found that the preoperative Compression_Ratio, Central_Ratio and 1/4-Lateral_Compression_Ratio in MRI and cervical segmental instability in dynamic X-ray could reflect the dynamic neural dysfunction of the spinal cord. Different Ax-CCM types corresponded to different DSSEP results at extension and flexion, suggesting divergent pathophysiology. These radiographic parameters could help evaluate disease severity and predict postoperative prognosis.Trial registration: The trial "动态诱发电位对脊髓型颈椎病诊断和预后评估(Dynamic Somatosensory Evoked Potentials for the diagnostic and prognostic evaluation for Cervical Spondylotic Myelopathy)" was retrospectively registered on April 30th, 2020 and the registration number is "伦审[2020]151号".

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An independent agreement study of modified Pfirrmann grading system for cervical inter-vertebral disc degeneration in cervical spondylotic myelopathy

British Journal of Neurosurgery ◽

10.1080/02688697.2020.1861431 ◽

2020 ◽

pp. 1-5

Author(s):

Chongqing Xu ◽

Mengchen Yin ◽

Wen Mo

Keyword(s):

Disc Degeneration ◽

Cervical Spondylotic Myelopathy ◽

Grading System ◽

Vertebral Disc ◽

Agreement Study

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An Independent Agreement Study of Modified Pfirrmann Grading System for Cervical Inter-vertebral Disc Degeneration in Cervical Spondylotic Myelopathy

10.21203/rs.3.rs-107456/v1 ◽

2020 ◽

Author(s):

Chongqing Xu ◽

Mengchen Yin ◽

Wen Mo

Keyword(s):

Disc Degeneration ◽

Cervical Spondylotic Myelopathy ◽

Clinical Care ◽

Weighted Kappa ◽

Motor Dysfunction ◽

Observer Agreement ◽

Grading System ◽

Observer Reliability ◽

Vertebral Disc ◽

Agreement Study

Abstract Background Neck pain, sensory disturbance and motor dysfunction in most patients suffered cervical spondylotic myelopathy (CSM). For CSM surgery, it is necessary to evaluate preoperative inter-vertebral disc degeneration (IDD) which determines whether to adopt fusion strategy, and postoperative IDD which is one of the main reasons for reoperation. Modified Pfirrmann grading system is commonly used to evaluate IDD. The objective of this study is to evaluate its reliability and reproducibility on cervical IDD in CSM patients, and to explore its clinical application value. Methods/Design: All 165 patients with CSM were enrolled. 6 physicians (3 spine surgeons and 3 radiologists) who have certain clinical experience were selected. They graded cervical inter-vertebral disc according to modified Pfirrmann grading system, we used intra-class correlation coefficient (ICC) and weighted kappa (wκ) to assess the inter- and intra-observer agreement. After 12 weeks, we repeated the analysis. Results The inter-observer reliability of modified Pfirrmann grading system was excellent with ICC value of 0.76 and near perfect with wκ value of 0.82. The intra-observer reproducibility of modified Pfirrmann grading system was excellent with ICC values ranging from 0.80–0.91, and near perfect with wκ values ranging from 0.83–0.92. Conclusion Modified Pfirrmann grading system has excellent inter-observer reliability and intra-observer reproducibility on cervical IDD in CSM. In addition, it indicates a good appliance among spine surgeons and radiologists, clinical and radiological studies applying it should be deemed accurate. Thus, modified Pfirrmann grading system can be widely used as an appropriate instrument in clinical care.

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Kinematics of an intervertebral disc with type 1 Modic change: mechanical and non-mechanical causes

10.21203/rs.3.rs-690484/v1 ◽

2021 ◽

Author(s):

Yuji Yamada ◽

Masatoshi Morimoto ◽

Toru Maeda ◽

Syogo Tomiyama ◽

Hirofumi Takami ◽

...

Keyword(s):

Disc Degeneration ◽

Magnetic Resonance Images ◽

Low Back ◽

Modic Change ◽

Segmental Instability ◽

The Difference ◽

Pfirrmann Grade ◽

The Relationship

Abstract BackgroundType 1 Modic change (MC) is associated with chronic low back pain and attributed to segmental instability. However, the relationship between type 1 MC and segmental instability is unclear. This study sought to clarify the role of mechanical abnormalities in type 1 MC.MethodReview of magnetic resonance images obtained for 727 patients over a 1-year period at our institution revealed 161 cases of type 1 MC. In 86 of these, the following indicators of mechanical abnormality could be evaluated on dynamic radiographs: segmental scoliosis (> 5°), forward slippage (> 1%), and posterior disc opening in flexion. Patients with one or more of these abnormalities were allocated to a mechanical group (n = 62, 70%) and those with no abnormality to a non-mechanical group (n = 26, 30%). The Pfirrmann grade of disc degeneration at the affected level was compared between the groups.ResultsSegmental scoliosis, slippage, and posterior opening was observed in 34, 21 and 37 cases, respectively. Severe disc degeneration (grade IV or V) was present in 43 cases (69%) in the mechanical group and in 12 cases (46%) in the non-mechanical group; the difference was statistically significant (p = 0.04).ConclusionWe propose that there are mechanical and non-mechanical variants of type 1 MC.

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Effect of Anulus Fibrosus Repair on Lumbar Spine Biomechanics

ASME 2009 Summer Bioengineering Conference, Parts A and B ◽

10.1115/sbc2009-205806 ◽

2009 ◽

Author(s):

S. Kode ◽

M. Gudipally ◽

T. Takigawa ◽

A. A. Espinoza Orías ◽

R. Natarajan ◽

...

Keyword(s):

United States ◽

Low Back Pain ◽

Back Pain ◽

Lumbar Spine ◽

Disc Degeneration ◽

Annual Incidence ◽

Low Back ◽

Spine Biomechanics ◽

Anulus Fibrosus ◽

Segmental Instability

Low back pain is sometimes related to, but not necessarily caused by, anulus fibrosus (AF) ruptures. Studies on low back pain have estimated an annual incidence of 5% and prevalence of 15% to 20% in United States alone [1]. Disc degeneration with or without herniation is frequently implicated in low back pain and sciatica, and is believed to be associated with segmental instability of the spine [2].

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LAMINOPLASTY AND CORPECTOMY IN THE TREATMENT OF CERVICAL SPONDYLOTIC MYELOPATHY

Coluna/Columna ◽

10.1590/s1808-185120181703193258 ◽

2018 ◽

Vol 17 (3) ◽

pp. 174-179

Author(s):

Dreval’ Maxim Dmitrievich ◽

Arestov Sergey Olegovich ◽

Petrosyan David Vazgenovich ◽

Kashcheev Alexey Alexeevich ◽

Vershinin Andrey Vyacheslavovich ◽

...

Keyword(s):

Cervical Spondylotic Myelopathy ◽

Clinical Symptoms ◽

Complete Recovery ◽

Neurological Dysfunction ◽

Level Of Evidence ◽

Segmental Instability ◽

History Of ◽

Prospective Comparative Study ◽

Initial Severity ◽

Significant Regression

ABSTRACT Introduction: Cervical Spondylotic myelopathy (CSM) is a disabling manifestation of extended cervical stenosis characterized by pronounced neurological dysfunction. Decompressive interventions contribute to significant regression of symptoms and, in some cases, complete recovery can be achieved. Objective: To explore the potential of laminoplasty in patients with extended cervical spondylotic stenoses complicated by myelopathy, and to develop approaches for surgical intervention in these patients. Methods: Fifty-six patients were included in the study. Laminoplasty was performed in 34 patients. Corpectomy was performed in 22 patients who made up the comparison group. The frequency and initial severity of concomitant non-neurological disorders in both groups were comparable. Results: Indications for laminoplasty were determined. They include: symptoms of spondylotic myelopathy, three or more levels of compression, preservation of lordosis, absence of signs of segmental instability, inability to perform anterior decompression, and age over 55 years. The presence of signs of segmental instability, kyphotic deformation, and history of mental disorders may be considered as contraindications for this surgery. Conclusions: Due to a number of advantages, laminoplasty is the treatment of choice for extended cervical spondylotic stenosis. Adequate selection of patients based on the evaluation of clinical symptoms, extension of stenosis, neurological signs and neuroimaging features enable excellent results to be achieved. Level of Evidence: II. Type of Study: Prospective comparative study.

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Magnetic Resonance Imaging and Dynamic X-ray's correlations with Dynamic Electrophysiological Findings in Cervical Spondylotic Myelopathy: a retrospective cohort study.

10.21203/rs.3.rs-41406/v2 ◽

2020 ◽

Author(s):

Zhengran Yu ◽

Kaiyuan Lin ◽

Jiacheng Chen ◽

Kuan-Hung Chen ◽

Yuguang Chen ◽

...

Keyword(s):

Magnetic Resonance Imaging ◽

Spinal Cord ◽

Magnetic Resonance ◽

Cervical Spondylotic Myelopathy ◽

T Test ◽

Resonance Imaging ◽

Segmental Instability ◽

X Ray ◽

Clinical Assessments ◽

Radiographic Parameters

Abstract Background: Dynamic somatosensory evoked potentials (DSSEP) can be used to disclose abnormalities of ascending sensory pathways at dynamic positions and diagnose cervical spondylotic myelopathy (CSM). However, radiographic tests including magnetic resonance imaging (MRI) and dynamic X-ray are used much more widely in the management of CSM. Our study aims to clarify the correlations between several radiographic parameters and the DSSEP results, and further determine their reliability with clinical data.Methods: We retrospectively enrolled 38 CSM patients with surgical intervention. DSSEP tests were performed before surgery. Amplitude ratios of DSSEP N13 and N20 waves at extension and flexion were calculated and recorded as N13_E, N20_E, N13_F, N20_F, respectively. Baseline severity was evaluated with the modified Japanese Orthopedic Association (mJOA) score and the Nurick grades. Prognosis was evaluated based on the 2-year recovery rate. Sagittal diameter and transverse areas of the cord and canal were measured and the the compressive ratios at the compressed site (Compression_Ratio), central (Central_Ratio), and 1/4-lateral points (1/4-Lateral_Compression_Ratio), and spinal cord/Canal Area Ratio were calculated. The intramedullary T2 hyperintensity patterns (Ax-CCM types) were also collected from MRI axial images. Dynamic X-rays were used to test for segmental instability of the cervical spine. The correlations between radiologic findings, DSSEP data, and clinical assessments were investigated.Results: We found that DSSEP N13_E and N13_F correlated with the Compression_Ratio, Central_Ratio, 1/4-Lateral_Compression_Ratio (Pearson, p<0.05) and Ax-CCM types (ANOVA, p<0.05) in MRI axial images and cervical segmental instability in dynamic X-ray (t-test, p<0.05). Apart from the 1/4-Lateral_Compression_Ratio, these radiographic parameters above also correlated with the baseline clinical assessments (Spearman or ANOVA or t-test, p<0.05) and postoperative recovery rate (Pearson or ANOVA or t-test, p<0.05).Conclusions: We found that the preoperative Compression_Ratio, Central_Ratio and 1/4-Lateral_Compression_Ratio in MRI and cervical segmental instability in dynamic X-ray could reflect the dynamic neural dysfunction of the spinal cord. Different Ax-CCM types corresponded to different DSSEP results at extension and flexion, suggesting divergent pathophysiology. These radiographic parameters could help evaluate disease severity and predict postoperative prognosis.Trial registration: The trial "动态诱发电位对脊髓型颈椎病诊断和预后评估(Dynamic Somatosensory Evoked Potentials for the diagnostic and prognostic evaluation for Cervical Spondylotic Myelopathy)" was retrospectively registered on April 30th, 2020 and the registration number is "伦审[2020]151号".

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Magnetic resonance imaging and dynamic X-ray’s correlations with dynamic electrophysiological findings in cervical spondylotic myelopathy: a retrospective cohort study

BMC Neurology ◽

10.1186/s12883-020-01945-4 ◽

2020 ◽

Vol 20 (1) ◽

Author(s):

Zhengran Yu ◽

Kaiyuan Lin ◽

Jiacheng Chen ◽

Kuan-Hung Chen ◽

Wei Guo ◽

...

Keyword(s):

Magnetic Resonance Imaging ◽

Spinal Cord ◽

Magnetic Resonance ◽

Cervical Spondylotic Myelopathy ◽

T Test ◽

Resonance Imaging ◽

Segmental Instability ◽

X Ray ◽

Clinical Assessments ◽

Radiographic Parameters

Abstract Background Dynamic somatosensory evoked potentials (DSSEP) can be used to disclose abnormalities of ascending sensory pathways at dynamic positions and diagnose cervical spondylotic myelopathy (CSM). However, radiographic tests including magnetic resonance imaging (MRI) and dynamic X-ray are used much more widely in the management of CSM. Our study aims to clarify the correlations between several radiographic parameters and the DSSEP results, and further determine their reliability with clinical data. Methods We retrospectively enrolled 38 CSM patients with surgical intervention. DSSEP tests were performed before surgery. Amplitude ratios of DSSEP N13 and N20 waves at extension and flexion were calculated and recorded as N13_E, N20_E, N13_F, N20_F, respectively. Baseline severity was evaluated with the modified Japanese Orthopedic Association (mJOA) score and the Nurick grades. Prognosis was evaluated based on the 2-year recovery rate. Sagittal diameter and transverse areas of the cord and canal were measured and the the compressive ratios at the compressed site (Compression_Ratio), central (Central_Ratio), and 1/4-lateral points (1/4-Lateral_Compression_Ratio), and spinal cord/Canal Area Ratio were calculated. The intramedullary T2 hyperintensity patterns (Ax-CCM types) were also collected from MRI axial images. Dynamic X-rays were used to test for segmental instability of the cervical spine. The correlations between radiologic findings, DSSEP data, and clinical assessments were investigated. Results We found that DSSEP N13_E and N13_F correlated with the Compression_Ratio, Central_Ratio, 1/4-Lateral_Compression_Ratio (Pearson, p < 0.05) and Ax-CCM types (ANOVA, p < 0.05) in MRI axial images and cervical segmental instability in dynamic X-ray (t-test, p < 0.05). Apart from the 1/4-Lateral_Compression_Ratio, these radiographic parameters above also correlated with the baseline clinical assessments (Spearman or ANOVA or t-test, p < 0.05) and postoperative recovery rate (Pearson or ANOVA or t-test, p < 0.05). Conclusions We found that the preoperative Compression_Ratio, Central_Ratio and 1/4-Lateral_Compression_Ratio in MRI and cervical segmental instability in dynamic X-ray could reflect the dynamic neural dysfunction of the spinal cord. Different Ax-CCM types corresponded to different DSSEP results at extension and flexion, suggesting divergent pathophysiology. These radiographic parameters could help evaluate disease severity and predict postoperative prognosis.

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Cervical spondylotic myelopathy associated with kyphosis or sagittal sigmoid alignment: outcome after anterior or posterior decompression

Journal of Neurosurgery Spine ◽

10.3171/2009.2.spine08385 ◽

2009 ◽

Vol 11 (5) ◽

pp. 521-528 ◽

Cited By ~ 112

Author(s):

Kenzo Uchida ◽

Hideaki Nakajima ◽

Ryuichiro Sato ◽

Takafumi Yayama ◽

Erisa S. Mwaka ◽

...

Keyword(s):

Cervical Spine ◽

Mechanical Stress ◽

Cervical Spondylotic Myelopathy ◽

Sagittal Alignment ◽

Japanese Orthopaedic Association ◽

Neutral Position ◽

Kyphotic Angle ◽

Segmental Instability ◽

The Mean

Object The effects of sagittal kyphotic deformities or mechanical stress on the development of cervical spondylotic myelopathy, or the reduction and fusion of kyphotic sagittal alignment have not been consistently documented. The aim in this study was to determine the effects of kyphotic sagittal alignment of the cervical spine in terms of neurological morbidity and outcome after 2 types of surgical intervention. Methods The authors retrospectively reviewed the records of 476 patients who underwent cervical spine surgeries for spondylotic myelopathy between 1993 and 2006 at their university medical center. Among these were identified 43 patients—30 men and 13 women, with a mean age of 58.8 years—who had cervical kyphosis exceeding 10° on preoperative sagittal lateral radiographs obtained in the neutral position, and their cases were analyzed in this study. Anterior decompression with interbody fusion was conducted in 28 patients, and en bloc open-door C3–7 laminoplasty in 15 patients. Both pre- and postoperative neurological, radiographic, and MR imaging findings were assessed in both surgical groups. Results The mean preoperative kyphotic angle in all 43 patients was 15.9 ± 5.9° in the neutral position. Segmental instability was noted in 26 patients (61%) and reversed dynamic spinal canal stenosis at the level above the local kyphosis in 22 (51%). Preoperative T2-weighted MR images showed high-intensity signal within the cord at and around the level of maximal compression or segmental instability in 28 patients (65%). The mean kyphotic angle in both the neutral and flexion positions was significantly smaller at 4–6 weeks after surgery in the anterior spondylectomy group than in the laminoplasty group (p < 0.001). Furthermore, the angle in the neutral position was significantly smaller on follow-up in the anterior spondylectomy group than in the laminoplasty group (p = 0.034). The transverse area of the spinal cord was significantly larger in the anterior spondylectomy group than in the laminoplasty group on follow-up (p = 0.037). Preoperative neurological scores (assessed using the Japanese Orthopaedic Association scale) and improvement on follow-up ≥ 2 years after treatment (average 3.3 years) were not significantly different between the 2 groups; however, there was a significant difference in Japanese Orthopaedic Association score at 4–6 weeks postoperatively (p = 0.047). Conclusions Kyphotic deformity and mechanical stress in the cervical spine may play an important role in neurological dysfunction. In a select group of patients with kyphotic deformity ≥ 10°, adequate correction of local sagittal alignment may help to maximize the chance of neurological improvement.

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