Biomechanical Effects on Cervical Spinal Cord and Nerve Root Following Laminoplasty for Ossification of the Posterior Longitudinal Ligament in the Cervical Spine: A Comparison Between Open-Door and Double-Door Laminoplasty Using Finite Element Analysis

Many clinical case series have reported the predisposing factors for C5 palsy and have presented comparisons of the two types of laminoplasty. However, there have been no biomechanical studies focusing on cervical spinal cord and nerve root following laminoplasty. The purpose of this study is to investigate biomechanical changes in the spinal cord and nerve roots following the two most common types of laminoplasty, open-door and double-door laminoplasty, for cervical ossification of the posterior longitudinal ligament (OPLL). A finite element (FE) model of the cervical spine and spinal cord with nerve root complex structures was developed. Stress changes in the spinal cord and nerve roots, posterior shift of the spinal cord, and displacement of the cervical nerve roots were analyzed with two types of cervical laminoplasty models for variations in the degree of canal occupying ratio and shape of the OPLL. The shape and degree of spinal cord compression caused by the OPLL had more influence on the changes in stress, posterior shift of the spinal cord, and displacement of the nerve root than the type of laminoplasty. The lateral-type OPLL resulted in imbalanced stress on the nerve roots and the highest nerve root displacement. Type of laminoplasty and shape and degree of spinal cord compression caused by OPLL were found to influence the changes in stress and posterior displacement of the cervical spinal cord and nerve roots. Lateral-type OPLL might contribute to the development of C5 palsy due to the imbalanced stress and tension on the nerve roots after laminoplasty.

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Case report of ervical myelopathy due to ossification of the posterior longitudinal ligament in association with flavum ligament ossification: MRI and CT appearance

Acta medica Lituanica ◽

10.6001/actamedica.v20i2.2696 ◽

2013 ◽

Vol 20 (2) ◽

pp. 79-83

Author(s):

Monique Boukobza ◽

Jurgita Ušinskienė ◽

Simona Letautienė

Keyword(s):

Spinal Cord ◽

Cervical Spine ◽

Double Layer ◽

Spinal Canal ◽

Mixed Type ◽

Cervical Spinal Cord ◽

Asian Population ◽

Posterior Longitudinal Ligament ◽

Cord Compression ◽

Cord Injury

Background. Our objective is to analyze the cervical spinal cord damage and spinal canal stenosis due to OPLL which usually affects the cervical spine and leads to progressive myelopathy in 50–60s in Asian population; to demonstrate the mixed type OPLL and to show OPLL specific dural penetration signs: “double- layer” and “C-sign” on imaging. Materials and methods. Subacute cord compression developed over a 3-month period in a 43-year-old Japanese patient. Severe spinal canal narrowing was related to the mixed type OPLL at C3–C4 through C6–C7 associated to flavum ligament ossification at T3–T4. Lateral radiograph of the cervical spine showed intraspinal ossification, CT demonstrated specific dural penetration signs, and MRI disclosed spinal cord compression. Laminectomy at C3–C7 was performed and decompression of the spinal cord was confirmed by postoperative MRI. Conclusions. Absolute cervical stenosis and association with other diseases (like calcification of flavum ligament) predispose the patient to develop more severe deficit earlier in the clinical course. Specific CT signs, “double-layer” and “C-sign”, show dural involvement. MRI is a very useful modality to identify the precise level and extent of the spinal cord injury. OPLL must be included in the differential diagnosis of subacute cervical myelopathy.

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Evaluation of Cervical Spine Surgery by Postoperative Myelography

Neurosurgery ◽

10.1227/00006123-198304000-00008 ◽

1983 ◽

Vol 12 (4) ◽

pp. 416-421 ◽

Cited By ~ 8

Author(s):

Charles A. Fager

Keyword(s):

Spinal Cord ◽

Cervical Spine ◽

Nerve Root ◽

Spontaneous Remission ◽

Cord Compression ◽

Cervical Disc ◽

Nerve Root Compression ◽

Cervical Fusion ◽

Cervical Spine Surgery ◽

Cervical Spine Fusion

Abstract After spontaneous remission of nerve root compression, a myelographic defect may persist. Similarly, myelopathy may remain nonprogressive for long periods despite appreciable myelographic deformity. Although operation may arrest or improve the symptoms of cervical disc lesions and spondylosis, the ultimate confirmation that entrapped neural elements have been relieved permanently can only be provided by postoperative myelography. Preoperative and postoperative myelography documents the significant improvement that can be achieved by using posterolateral and posterior approaches to the cervical spine in patients with nerve root or spinal cord compression. The results in this group of patients were achieved with none of the disadvantages or complications of cervical spine fusion or of the interbody removal of cervical disc tissue, also leading to cervical fusion.

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Biomechanical effects of spinal cord compression due to ossification of posterior longitudinal ligament and ligamentum flavum: A finite element analysis

Medical Engineering & Physics ◽

10.1016/j.medengphy.2013.01.006 ◽

2013 ◽

Vol 35 (9) ◽

pp. 1266-1271 ◽

Cited By ~ 11

Author(s):

Yoon Hyuk Kim ◽

Batbayar Khuyagbaatar ◽

Kyungsoo Kim

Keyword(s):

Spinal Cord ◽

Finite Element Analysis ◽

Finite Element ◽

Spinal Cord Compression ◽

Ligamentum Flavum ◽

Posterior Longitudinal Ligament ◽

Cord Compression ◽

Element Analysis

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Analysis of myelomalacia and posterior longitudinal Ligament ossification as prognostic factors in patients with cervical spondylotic myelopathy submitted to laminoplasty

JBNC - JORNAL BRASILEIRO DE NEUROCIRURGIA ◽

10.22290/jbnc.v32i2.1957 ◽

2021 ◽

Vol 32 (2) ◽

pp. 297-301

Author(s):

Desirée Elizabeth Pasqualetto Antikievicz ◽

Giulio Bartié Rossi ◽

Marcos Vinicius Calfatt Maldaun ◽

Paulo Henrique Pires de Aguiar ◽

Daniel Gripp ◽

...

Keyword(s):

Spinal Cord ◽

Prognostic Factors ◽

Cervical Spondylotic Myelopathy ◽

Cervical Spinal Cord ◽

Posterior Longitudinal Ligament ◽

The Elderly ◽

Cervical Canal ◽

Open Door ◽

Cord Injury ◽

Posterior Longitudinal Ligament Ossification

Background: Cervical spondylotic myelopathy is a degenerative disease of the intervertebral disc and vertebral body of the spine that causes cervical spinal cord injury due to central vertebral canal stenosis. Its prevalence is higher in the elderly. Treatment is usually surgical when the spinal cord is affected either clinically with pyramidal release or radiologically with the altered spinal cord. Objective: The rationale of this study is to analyze the myelomalacia and the ossification of posterior longitudinal ligament as prognostic factors in the postoperative evolution of patients with cervical canal compression who underwent laminoplasty by open-door or french-door techniques. Methods: We performed a retrospective analysis of 18 surgical cases of spondylotic cervical myelopathy of the same senior neurosurgeon, using the chi-square test to analyze prognostic factors for patients’ postoperative evolution in the Nurick scale, after open-door or french-door laminoplasty. Results: The comparison between pre and postoperative showed an improvement of 71.43% of cases that did not have ligament ossification compared to 45.45% of cases that presented posterior longitudinal ligament ossification. Also, there was a better prognosis in patients without myelomalacia, as 71.43% of them improved their condition against only 45.45% improvement in those with myelomalacia. Conclusion: There is a need for further studies with larger samples to expressively prove that the presence of longitudinal ligament ossification and the previous presence of myelomalacia are factors of worse prognosis in the postoperative evolution of patients with cervical spondylotic myelopathy submitted to laminoplasty.

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Analysis of risk factors for C5 nerve root paralysis after posterior cervical decompression

BMC Musculoskeletal Disorders ◽

10.1186/s12891-021-04434-y ◽

2021 ◽

Vol 22 (1) ◽

Author(s):

Bo Liu ◽

Yanchen Chu ◽

Jinfeng Ma ◽

Xiaojie Tang ◽

Junpeng Pan ◽

...

Keyword(s):

Risk Factors ◽

Spinal Cord ◽

Cervical Spine ◽

Nerve Root ◽

Posterior Longitudinal Ligament ◽

Spine Curvature ◽

Independent Risk Factors ◽

T2 Hyperintensity ◽

Intervertebral Foramina ◽

Posterior Longitudinal Ligament Ossification

Abstract Background C5 nerve root paralysis is a nonnegligible complication after posterior cervical spine surgery (PCSS). The cause of its occurrence remains controversial. The purpose of this study was to analyse the incidence of and risk factors for C5 nerve root paralysis after posterior cervical decompression. Methods We retrospectively analysed the clinical data of 640 patients who underwent PCSS in the Department of Orthopaedics, Affiliated Hospital of Qingdao University from September 2013 to September 2019. According to the status of C5 nerve root paralysis after surgery, all patients were divided into paralysis and normal groups. Univariate and multivariate analyses were used to determine the independent risk factors for C5 nerve root paralysis. A receiver operating characteristic (ROC) curve was used to demonstrate the discrimination of all independent risk factors. Results Multivariate logistic regression analysis revealed that male sex, preoperative cervical spine curvature, posterior longitudinal ligament ossification, and preoperative C4/5 spinal cord hyperintensity were independent risk factors for paralysis, whereas the width of the intervertebral foramina was an independent protective factor for paralysis. The area under the curve (AUC) values of the T2 signal change at C4-C5, sex, cervical foramina width, curvature and posterior longitudinal ligament ossification were 0.706, 0.633, 0.617, 0.637, and 0.569, respectively. Conclusions Male patients with C4-C5 intervertebral foramina stenosis, preoperative C4-C5 spinal cord T2 high signal, combined with OPLL, and higher preoperative cervical spine curvature are more likely to develop C5 nerve root paralysis after surgery. Among the above five risk factors, T2 hyperintensity change in C4-C5 exhibits the highest correlation with C5 paralysis and strong diagnostic power. It seems necessary to inform patients who have had cervical spine T2 hyperintensity before surgery of C5 nerve root paralysis after surgery, especially those with altered spinal cord T2 signals in the C4-C5 segment.

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